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Classifications

Mechanistic Nosology

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Mappings

MONDO

MONDO:0016342 familial isolated arrhythmogenic right ventricular dysplasia Not Yet Curated

MONDO:0016342 is the familial, isolated (non-syndromic) presentation of ARVC, defined as intersection_of MONDO:0016587 plus RO:0000053 MONDO:0021128 (has an isolated presentation), and is_a the MONDO:0016587 anchor of this entry. It is the direct parent of the numbered ARVD series mapped below. This entry curates the familial autosomal-dominant desmosomal disease it denotes, so the term is covered here. narrowMatch rather than exactMatch because the MONDO:0016587 anchor also subsumes the syndromic cardiocutaneous recessive forms (Naxos, Carvajal), which are curated as their own entries and which the "isolated presentation" restriction of MONDO:0016342 excludes.

MONDO:0011459 arrhythmogenic right ventricular dysplasia 5 Not Yet Curated

ARVD5 is defined as the TMEM43 form (intersection_of RO:0004003 HGNC:28472) and sits under MONDO:0016342 (familial isolated ARVD), which is_a the MONDO:0016587 anchor of this entry. This entry curates TMEM43 (hgnc:28472), so the child term is covered here. narrowMatch because the anchor subsumes the whole numbered ARVD series.

MONDO:0012434 arrhythmogenic right ventricular dysplasia 10 Not Yet Curated

ARVD10 is defined as the DSG2 form (intersection_of RO:0004003 HGNC:3049) and sits under MONDO:0016342, which is_a the MONDO:0016587 anchor of this entry. This entry curates DSG2 (hgnc:3049), so the child term is covered here. narrowMatch because the anchor subsumes the whole numbered series.

MONDO:0012506 arrhythmogenic right ventricular dysplasia 11 Not Yet Curated

ARVD11 is defined as the DSC2 form (intersection_of RO:0004003 HGNC:3036) and sits under MONDO:0016342, which is_a the MONDO:0016587 anchor of this entry. This entry curates DSC2 (hgnc:3036), so the child term is covered here. narrowMatch because the anchor subsumes the whole numbered series.

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Inheritance

1

Autosomal dominant inheritance HP:0000006

Most familial ARVC is inherited in an autosomal dominant fashion with reduced penetrance and variable expressivity.

Autosomal dominant inheritance Penetrance: INCOMPLETE Expressivity: VARIABLE

Show evidence (2 references)

PMID:18662195 SUPPORT Human Clinical

"ARVC is associated with autosomal dominant mutations of desmosomal proteins, including plakophilin-2 (PKP-2), desmoplakin (DSP), junctional plakoglobin (JUP), desmoglein-2 (DSG-2) and desmocollin-2 (DSC-2) [9–11]."

This directly supports autosomal-dominant inheritance across the canonical desmosomal gene spectrum.

PMID:24817548 SUPPORT Human Clinical

"incorporating genetic results in AC risk stratification is hampered by incomplete penetrance and an extremely variable clinical expression. Mutation carriers may present with SCD but can also remain without signs and symptoms of the disease into old age."

This directly supports the incomplete penetrance and variable expressivity that characterise the inherited, autosomal dominant ARVC substrate.

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Mechanistic Hypotheses

1

Anti-DSG2 Causal Injury Driver or Amplifier

anti_dsg2_causal_injury_driver_or_amplifier EMERGING

Evidence balance 12 support 2 refute

Anti-DSG2 antibodies may causally worsen genetically vulnerable myocardium either as antecedent drivers or as injury-dependent amplifiers. Candidate mechanisms are direct impairment of junctional adhesion or electrical coupling and Fc-receptor- or complement-dependent injury. A signal that merely follows tissue damage without antigen-specific functional activity is the null, biomarker-only alternative and refutes this causal hypothesis. DAMP-mediated innate activation remains a separately tested possible upstream or parallel branch rather than a presumed linear cascade. Current evidence does not warrant wiring this emerging hypothesis to a causal pathophysiology edge, defining a clinical biomarker, or proposing an immune-directed treatment.

Deep research

OpenScientist citations 18 citations 2026-07-26T08:24:52.655852

Show evidence (14 references)

PMID:42406223 SUPPORT Other

"While these observations support a possible role for autoimmunity, the causal contribution of these autoantibodies to myocardial injury and disease progression remains incompletely established and constitutes a proposed rather than confirmed model."

The seed narrative review explicitly identifies the causal autoimmune interpretation as a working model while emphasizing that it remains unconfirmed. This supports testing an emerging causal hypothesis, not treating an injury-associated antibody signal as part of that hypothesis.

PMID:30239670 SUPPORT Human Clinical

"We identified anti-DSG2 antibodies in 12/12 and 25/25 definite ARVC cohorts and 7/8 borderline subjects."

The original small discovery and validation cohorts support antibody occurrence in clinically defined ARVC. The study lacked myocarditis and inflammatory-cardiomyopathy comparators, so these case-control results do not establish disease specificity, temporal order, or causality.

PMID:30239670 SUPPORT In Vitro

"antibodies caused gap junction dysfunction, a common feature of ARVC, in vitro."

Purified IgG from two ARVC patients and a commercial anti-DSG2 antibody provide an initial functional signal in human iPSC-derived cardiomyocytes. The experiment did not use antigen-specific depletion and add-back for patient IgG or establish Fc or complement dependence, necessity, or sufficiency in vivo.

+ 11 more references

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Discussions and Knowledge Gaps

1

Are anti-DSG2 or broader anti-intercalated-disc antibodies antecedent drivers, injury-dependent amplifiers, or non-pathogenic markers of desmosomal cardiomyocyte damage, and is DAMP-mediated innate activation an upstream cause of adaptive autoimmunity or a parallel injury-response branch?

KNOWLEDGE GAP OPEN gap_arvc_anti_dsg2_autoimmune_causality

Attached to

mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier pathophysiology#Intercalated-disc adhesion failure pathophysiology#Gap-junction and sodium-channel remodeling pathophysiology#Cardiomyocyte apoptosis and loss pathophysiology#Fibrofatty myocardial replacement

Cross-sectional serology and small functional studies leave several mutually exclusive interpretations open. The 2018 report found anti-DSG2 in 12 of 12 and 25 of 25 definite ARVC cases and related antibody density to premature ventricular contractions, but its controls did not include myocarditis and functional testing used purified total IgG from only two patients. Two independent 2026 Boxer cohorts then found anti-DSG2 to be nearly ubiquitous or non-discriminatory between affected and screened controls, while troponin and NT-proBNP outperformed the antibody in one study. These findings refute the original model-specific diagnostic anchor without deciding whether a pathogenic human subset exists. A later 15-patient study found catalytic activity against DSG2 and N-cadherin and reduced cohesion in murine culture systems, yet its ELISAs did not detect anti-DSG2 binding, only six IgG fractions reduced cellular cohesion, and no antigen-specific depletion and add-back or in-vivo transfer established that a DSG2-reactive clone was responsible. Family data associate broader anti-heart and anti-intercalated-disc antibodies with severity but cannot establish whether they precede disease. A 2026 follow-up found higher anti-DSG2 levels in 101 definite ARVC cases than in selected Ebstein-anomaly, Eisenmenger-syndrome, and healthy controls, but the diagnostic cutoff was derived in that same single-centre cohort. Its separate higher prognostic threshold tracked cardiac death or transplantation rather than arrhythmic events, and no longitudinal samples or myocarditis/DCM comparators were included. This is compatible with, rather than a refutation of, the 2024 multicenter primary study (PMID:39597880), which found 56% anti-DSG2 positivity among 77 ARVC cases and 48% among 91 myocarditis or DCM cases, with no titer difference between those disease groups and no ARVC clinical correlate for anti-DSG2 positivity. Persistent anti-DSG2 signals after COVID-19 further show that the response is not confined to ARVC. A newer functional study found cohesion loss for total IgG from only three of six broader ACM donors; GSK-3β inhibition rescued the responder phenotype but did not identify DSG2-specific activity or establish a treatment target. Separately, cytosolic-DNA–cGAS epistasis in a Dsp-deletion mouse, TLR hypersensitivity in human DSP engineered heart tissue, and IL-1β neutralization in a Dsg2-mutant mouse support causal or sensitizing innate branches. None measured antibody generation or antibody-dependent injury, and their DSP, broader ACM, or homozygous-mouse scope cannot be generalized to a human ARVC DAMP-to-autoantibody sequence. Resolving temporal order, antigen specificity, target accessibility, and necessity or sufficiency is therefore required before adding a causal immune edge, clinical biomarker, immunosuppressive treatment, or a single DAMP-to-autoantibody cascade.

Proposed experiments

Genotype-stratified longitudinal autoantibody origin and function study

prospective longitudinal mechanistic cohort study

exp_arvc_longitudinal_antibody_origin_and_function

Prospectively follow genotype-positive and gene-elusive ARVC participants, including unaffected variant-positive relatives, through quiescent, myocarditis-like hot-phase, and recovery intervals. Sample clinically matched inflammatory and structural cardiac controls on the same schedule, use orthogonal blinded antibody assays, and connect within-person antibody trajectories to injury, imaging, rhythm, and ex-vivo IgG function.

Model systems

Genotype-stratified ARVC natural-history cohort

Enroll DSP-, PKP2-, DSG2-, and other genotype-positive ARVC participants, gene-elusive cases, and phenotype-negative variant carriers. Include both sexes, pediatric and adult strata, and prespecified exercise and infection exposures without pooling distinct genotypes as though they share one inflammatory trajectory.

human NCBITaxon:9606

Clinically relevant cardiac comparator cohort

Match acute myocarditis, dilated cardiomyopathy, cardiac sarcoidosis, right-ventricular pressure or volume overload, post-infection cardiac injury, and healthy controls by age, sex, sampling phase, and injury burden where feasible.

human NCBITaxon:9606

Perturbations

Within-person injury and recovery time course

mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier

Obtain scheduled baseline specimens plus event-triggered samples before treatment where possible, during peak troponin or imaging activity, and through recovery. Record infection, exercise, immunomodulation, heart failure therapy, and arrhythmia procedures as time-varying exposures.

Antigen-specific IgG depletion and add-back

mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier

Purify total IgG from serial samples, affinity-deplete DSG2-reactive fractions with independently verified native extracellular DSG2, and add the eluted fraction back at its measured concentration. Compare intact IgG with matched Fab and Fc fragments and heat-inactivated or complement-reconstituted conditions.

Readouts

Orthogonal antibody identity and trajectory

mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier

Compare preregistered ELISA, immunofluorescence, native-cell binding, immunoprecipitation, and cleavage assays. Map epitope, isotype, affinity, glycosylation, clonotype, and cross-reactivity to N-cadherin and other intercalated-disc antigens at every longitudinal phase.

orthogonal autoantibody profiling B-cell receptor repertoire sequencing

Direction: THRESHOLD DEPENDENT

Necrotic injury and innate immune chronology

discussions#gap_arvc_anti_dsg2_autoimmune_causality

Quantify troponin, cell-free cardiac DNA, HMGB1 and other candidate DAMPs, cytokines, complement products, cardiac magnetic resonance edema and scar, positron-emission tomography inflammation, ventricular function, and biopsy findings when clinically obtained. Where tissue permits, distinguish necrotic injury from apoptosis rather than mapping all cardiomyocyte loss to the existing apoptosis-only node.

serial cardiac magnetic resonance imaging plasma injury and immune mediator profiling

Direction: THRESHOLD DEPENDENT

Electrical and adhesion effect of serial IgG

pathophysiology#Gap-junction and sodium-channel remodeling

At participant-matched concentrations, test intact, depleted, and add-back IgG in mechanically loaded human cardiomyocyte cultures for DSG2 accessibility and cleavage, cell-cell adhesion, Cx43 localization, conduction velocity, gap-junction transfer, cell death, complement deposition, and immune-cell recruitment.

cardiomyocyte adhesion and conduction assay antigen-specific immunoadsorption and add-back assay

Direction: NEGATIVE

Controls

Assay and temporal-bias controls

Lock cutoffs before outcome analysis, blind laboratories to diagnosis and phase, include bridge samples and calibrators across sites, verify native antigen folding and Fc-tag artifacts, and repeat decisive results with a second antigen preparation and laboratory.

Disease and injury-burden controls

Analyze each comparator separately and match or adjust for troponin, scar, ventricular function, renal function, infection timing, exercise, genotype, age, sex, and immunomodulatory exposure. Do not derive a diagnostic cutoff and test it in the same cohort.

Decision criterion

An antecedent pathogenic contribution requires a reproducible antibody clone or activity to be present or rise before objective injury within individuals, predict subsequent injury beyond genotype and prior disease burden, bind native cardiomyocyte DSG2, and produce an effect lost by antigen-specific depletion and restored by concentration-matched add-back. An amplifier is supported when the activity appears after structural injury but specifically worsens adhesion, conduction, or immune injury. A marker is favored when titers follow troponin, DAMP, or scar burden but depletion and add-back do not alter function. Similar phase- and injury-matched trajectories in myocarditis, sarcoidosis, post-infection injury, or right-ventricular overload support an injury-nonspecific response; failure of orthogonal assays supports assay artifact. Either biomarker-only result is the null outcome and refutes the causal driver-or-amplifier hypothesis. This study can establish temporal and ex-vivo support but is not alone sufficient for clinical biomarker adoption or therapeutic targeting.

Would support

mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier

Would refute

mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier

Antigen-specific anti-DSG2 causal epistasis under mechanical stress

antigen-specific cardiac autoantibody causal epistasis study

exp_arvc_anti_dsg2_causal_epistasis

Reconstruct patient antibody activity in isogenic human cardiac microtissues and genotype-specific animal models. Separate antigen binding or catalytic effects from Fc-receptor, complement, cellular cytotoxicity, and DAMP-sensing pathways using adsorption and add-back, monoclonal reconstruction, rescue, and branch-specific epistasis.

Model systems

Isogenic human mechanically loaded cardiac immune microtissue

Combine ventricular iPSC-derived cardiomyocytes with cardiac fibroblasts, endothelial cells, macrophages, and natural killer cells in an electrically paced, mechanically loaded format. Use multiple donor backgrounds and matched wild-type, DSP-, PKP2-, and DSG2-variant lines.

human NCBITaxon:9606

Genotype-specific arrhythmogenic cardiomyopathy models

Use sex-balanced, age-matched Dsp-, Pkp2-, and Dsg2-perturbed mice with longitudinal telemetry and imaging. Include wild-type recipients and prespecified low- and high-mechanical-load conditions while separating developmental from adult-onset injury. Before antibody transfer, demonstrate binding to native murine Dsg2 and the intended epitope. For Fc- or complement-dependent questions, use variable regions reformatted onto a species-compatible murine Fc with murine complement, or validated human DSG2/Fc-gamma-receptor/complement-humanized recipients.

house mouse NCBITaxon:10090

Perturbations

Patient anti-DSG2 loss-and-add-back series

mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier

Compare total patient IgG, DSG2-depleted IgG, the affinity-eluted add-back fraction, nonbinding IgG, matched Fab and Fc fragments, and sequence-defined monoclonal antibodies reconstructed from expanded DSG2-reactive B-cell clonotypes. Confirm binding to intact cardiomyocyte DSG2 and exclude N-cadherin or unrelated protease activity. In mice, interpret only reagents with verified native Dsg2 cross-reactivity and species-compatible effector handling, or use the validated humanized recipients.

Antigen and effector-pathway epistasis

pathophysiology#Intercalated-disc adhesion failure

Alter the mapped DSG2 epitope without disrupting baseline adhesion, then independently block Fc-gamma receptors, complement, natural-killer cell cytotoxicity, candidate catalytic activity, GSK-3β, and p38 signaling. Rescue with an antibody-insensitive but adhesion-competent DSG2 allele. Treat rescue at a shared downstream signaling node as mechanistically non-specific unless antigen-specific loss and add-back also identify the initiating antibody activity.

Parallel DAMP-sensing branch perturbation

discussions#gap_arvc_anti_dsg2_autoimmune_causality

Manipulate HMGB1 or nucleic-acid release and cGAS-STING, selected TLR, NLRP3, or IL-1β signaling independently of antibody exposure. Cross these perturbations with antigen-specific antibody loss and add-back so a parallel innate branch is distinguishable from a required DAMP-to-antibody sequence. Quantify necrotic and apoptotic cell death separately rather than presuming that DAMP release reports apoptosis.

Readouts

Junctional target engagement and function

pathophysiology#Intercalated-disc adhesion failure

Quantify native DSG2 occupancy or cleavage, desmosomal ultrastructure, intercellular force, Cx43 and Nav1.5 localization, dye coupling, conduction velocity, triggered activity, and mechanical-load-dependent cell loss with blinded longitudinal analysis.

super-resolution junctional imaging force spectroscopy and multielectrode mapping

Direction: NEGATIVE

Immune injury and remodeling

pathophysiology#Fibrofatty myocardial replacement

Resolve complement deposition, Fc-receptor activation, cytotoxicity, macrophage states, cytokines, DAMPs, fibrosis, adipose replacement, ventricular function, and arrhythmia from acute exposure through remodeling.

spatial single-cell immune profiling telemetry, imaging, and quantitative histopathology

Direction: THRESHOLD DEPENDENT

Controls

Antigen and immunoglobulin specificity controls

Use participant-matched control IgG, myocarditis and post-infection IgG, irrelevant antigen adsorption, sham elution, isotype-matched monoclonal controls, endotoxin testing, complement-free and reconstituted media, and blinded replication with independently prepared antibody.

Model and branch controls

Include no-load and matched-load conditions, genotype-matched untreated controls, wild-type recipients, Fc-receptor and complement single perturbations, DAMP-pathway perturbations without antibody, and antibody exposure without immune cells. Measure antibody pharmacokinetics and myocardial access rather than assuming surface epitope availability.

Cross-species antigen and effector compatibility controls

Before interpreting an in-vivo transfer, verify binding and antigen occupancy for the native DSG2 ortholog expressed in that recipient, plus Fc-gamma-receptor engagement and complement activation for the exact antibody format. Where recipients express murine Dsg2, demonstrate cross-reactivity directly; otherwise validate that the humanized target and effector components are functional. Treat an incompatible format as a failed model-transfer control, not as evidence against causality.

Decision criterion

A direct autoantibody driver requires a sequence-defined anti-DSG2 antibody or affinity-purified fraction to reproduce junctional, electrical, and tissue injury by itself; loss of effect after DSG2-specific adsorption or epitope alteration; restoration by add-back; and the predicted antigen or effector-pathway rescue in both human tissue and an independent in-vivo model. The in-vivo arm counts toward this criterion only after antigen and Fc/complement compatibility are verified; otherwise effector inference is bounded to the human microtissue and a negative mouse result is non-informative. Activity only after pre-existing desmosomal injury or mechanical stress, with a reproducible increase in injury magnitude, supports an amplifier. Association without antigen-specific functional effects is the biomarker-only null and refutes this causal hypothesis. Persistence after DSG2 adsorption or epitope rescue, equal effects from control or inflammatory-disease IgG, failure to reach myocardium, or dependence on nonspecific protease contamination also refutes an anti-DSG2-specific mechanism. Independent DAMP effects after antibody removal establish a parallel innate branch; DAMP perturbation must alter antibody generation and antibody-dependent injury in order to support a serial cascade.

Would support

mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier

Would refute

mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier

Show evidence (3 references)

PMID:40608429 SUPPORT Model Organism

"Deletion of the Mb21d1 gene encoding CGAS in the Myh6-McmTam Dspfl/fl mice prolonged survival, improved cardiac function, attenuated fibrosis, and reduced cell death."

Genetic epistasis supports a causal cytosolic-DNA–cGAS contribution in a severe homozygous cardiomyocyte-Dsp deletion mouse, but systemic rather than cardiomyocyte-specific Mb21d1 deletion limits cell-of-origin inference and did not reduce arrhythmia or conduction defects. This is not human ARVC evidence, and the study did not test anti-DSG2 production or antibody-dependent injury.

PMID:38768074 SUPPORT In Vitro

"DSPtv EHTs displayed heightened sensitivity to TLR stimulation, and when subjected to strain, DSPtv EHTs developed functional deficits, indicating reduced contractile reserve compared with healthy controls."

Patient-derived engineered heart tissues with heterozygous DSP truncating variants support genotype-dependent susceptibility to innate stimulation. The study models DSP-associated myocarditis rather than exact ARVC, does not establish which endogenous DAMP, if any, initiates human ARVC, and contains no anti-DSG2 measurement or antibody perturbation. It therefore supports a parallel innate branch rather than a serial autoimmune cascade.

PMID:42090754 SUPPORT Model Organism

"we treated Dsg2mut/mut mice with an anti-IL1B neutralizing antibody and observed attenuated fibrosis, reduced levels of inflammatory cytokines and chemokines, preserved cardiac function, and diminished conduction slowing and automaticity"

The intervention portion of this mixed human-and-mouse study gives causal support to an IL-1β inflammatory branch in homozygous Dsg2-mutant mice. It did not measure or remove anti-DSG2 antibodies, establish a DAMP source, or test human treatment, so the result cannot be used to infer a DAMP-to-antibody chain or an immune-directed ARVC therapy.

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Pathophysiology

8

Intercalated-disc adhesion failure

Pathogenic variation in core desmosomal genes disrupts mechanical cell-cell adhesion at cardiomyocyte intercalated discs. PKP2, DSP, DSG2, DSC2, and JUP form the canonical desmosomal core represented here; the gene-level validity annotations below preserve the strength of each available assertion.

cardiac muscle cell CL:0000746

PKP2 hgnc:9024 DSP hgnc:3052 DSG2 hgnc:3049 DSC2 hgnc:3036 JUP hgnc:6207

cell-cell adhesion GO:0098609 ↓ DECREASED

myocardium UBERON:0002349

Experimental models

Heterozygous plakoglobin-deficient (plakoglobin+/-) mouse OTHER Plakoglobin haploinsufficiency reproduces the desmosomal adhesion defect in vivo, and endurance training accelerates its functional and arrhythmic consequences - the model system behind the exercise EXACERBATES edge on this node.

Downstream

Gap-junction and sodium-channel remodeling Desmosomal dysfunction changes connexin43 and Nav1.5 abundance or localization at the intercalated disc.

Cardiomyocyte apoptosis and loss Mechanical dissociation under repeated myocardial stress can progress to cardiomyocyte injury, apoptosis, and loss.

Nuclear plakoglobin and canonical Wnt suppression Desmosomal disruption can redistribute plakoglobin to the nucleus and reduce canonical Wnt/beta-catenin signaling.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Desmosomal dysfunction due to a gene mutation may give rise to loss of mechanical cell-cell adhesion"

This directly supports loss of mechanical cardiomyocyte adhesion as the proximal lesion.

Gap-junction and sodium-channel remodeling

Reduced connexin43 expression or intercalated-disc localization impairs electrical coupling, while altered Nav1.5 distribution slows ventricular conduction. Electrical remodeling can precede overt fibrofatty disease.

cardiac muscle cell CL:0000746

gap junction assembly GO:0016264 ↓ DECREASED transmembrane transport GO:0055085 ↓ DECREASED

Downstream

Arrhythmogenic slow-conduction substrate Electrical uncoupling and reduced sodium current create slow, heterogeneous activation that predisposes to ventricular tachyarrhythmia.

Show evidence (1 reference)

PMID:18662195 SUPPORT Human Clinical

"Reduced connexin43 expression and localization to the intercalated disk occurs in heterozygous human PKP-2 mutations, potentially explaining the delayed conduction and propensity to develop arrhythmias seen in this disease."

Human myocardial tissue directly demonstrates connexin43 remodeling in heterozygous PKP2-related ARVC.

Nuclear plakoglobin and canonical Wnt suppression

Nuclear plakoglobin can suppress canonical Wnt/beta-catenin signaling and increase adipogenic and fibrogenic gene expression. This branch is retained as provisional because its direct evidence is primarily experimental.

Wnt signaling pathway GO:0016055 ↓ DECREASED fat cell differentiation GO:0045444 ↑ INCREASED

Downstream

Fibrofatty myocardial replacement Increased adipogenic and fibrogenic programs promote the characteristic fibro-adipose tissue phenotype.

Show evidence (1 reference)

PMID:16823493 SUPPORT In Vitro

"suppression of DP expression leads to nuclear localization of the desmosomal protein plakoglobin and a 2-fold reduction in canonical Wnt/beta-catenin signaling through Tcf/Lef1 transcription factors. The ensuing phenotype is increased expression of adipogenic and fibrogenic genes and..."

This directly supports the experimental Wnt-suppression branch and its adipogenic and fibrogenic transcriptional consequences.

Cardiomyocyte apoptosis and loss

Repeated mechanical injury in desmosome-deficient myocardium can cause cardiomyocyte apoptosis and depletion, creating space for replacement tissue.

cardiac muscle cell CL:0000746

Downstream

Fibrofatty myocardial replacement Loss of cardiomyocytes is followed by fibrous and adipose replacement of the depleted myocardium.

Show evidence (1 reference)

PMID:16823493 SUPPORT Model Organism

"Heterozygous DP-deficient mice exhibited excess adipocytes and fibrosis in the myocardium, increased myocyte apoptosis, cardiac dysfunction, and ventricular arrhythmias, thus recapitulating the phenotype of human ARVC."

Desmoplakin-deficient mice support myocyte apoptosis as part of the fibrofatty cardiomyopathy phenotype.

Fibrofatty myocardial replacement

Progressive replacement of myocardium by fibrous and adipose tissue is the defining structural lesion. It often predominates in the right ventricle but may extend to the left ventricle.

cardiac muscle cell CL:0000746 fibroblast of cardiac tissue CL:0002548 adipocyte CL:0000136

tissue remodeling GO:0048771 ↑ INCREASED

heart right ventricle UBERON:0002080

Downstream

Scar-related conduction heterogeneity Fibrofatty architectural disruption forces discontinuous activation through zig-zag pathways and creates load mismatch.

Progressive ventricular contractile dysfunction Loss of functional myocardium and adverse chamber remodeling impair ventricular pump function.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Arrhythmogenic cardiomyopathy (AC), also known as arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C), is a hereditary disease characterised by ventricular arrhythmias, right ventricular and/or left ventricular dysfunction, and fibrofatty replacement of cardiomyocytes."

This directly identifies fibrofatty cardiomyocyte replacement as a defining human disease feature.

Arrhythmogenic slow-conduction substrate

Early intercalated-disc electrical remodeling and later fibrofatty architectural remodeling converge on slow, heterogeneous conduction that supports ventricular ectopy, reentry, and malignant tachyarrhythmia.

heart right ventricle UBERON:0002080

Downstream

Ventricular tachycardia Slow, heterogeneous ventricular activation supports reentrant ventricular tachycardia.

Premature ventricular contraction The arrhythmogenic myocardium produces frequent ventricular ectopy.

Palpitations Ventricular ectopy or tachycardia is perceived clinically as palpitations.

Syncope Sustained ventricular arrhythmia can cause transient cerebral hypoperfusion and syncope.

Sudden cardiac death Reentrant ventricular arrhythmia can progress through fast VT or ventricular fibrillation to sudden cardiac death.

Epsilon wave Delayed terminal right-ventricular activation can appear as an epsilon wave on the surface ECG.

T-wave inversion Right-precordial T-wave inversion is a repolarization manifestation of diseased right-ventricular myocardium, but its precise causal bridge from the slow-conduction substrate is not fully resolved.

Show evidence (1 reference)

PMID:18662195 SUPPORT Human Clinical

"The decrease of connexin43 among ARVC patients assessed in this study provides an explanation for the conduction delay and resultant arrhythmias seen in ARVC."

Human myocardial findings support delayed conduction as the substrate for arrhythmia.

Progressive ventricular contractile dysfunction

Loss and replacement of contractile myocardium impair right-ventricular and sometimes left-ventricular function, producing chamber remodeling and eventual heart failure.

heart right ventricle UBERON:0002080

Downstream

Right ventricular dilatation Loss of contractile myocardium and adverse remodeling enlarge the right ventricular chamber.

Congestive heart failure Advanced ventricular pump dysfunction culminates in symptomatic heart failure.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"AC can present in four clinical stages which do not necessarily proceed from one into the other: 1) concealed stage without or with minimal structural disease, although SCD may occur, 2) overt stage with structural alterations of primarily the right ventricle, and episodes of monomorphic VT, 3)..."

The clinical staging evidence supports progression from ventricular structural involvement to biventricular disease and end-stage failure.

✶

Histopathology

1

Fibrous replacement of right ventricular free wall myocardium

Endomyocardial biopsy can show marked loss of right-ventricular myocytes with fibrous replacement of the free wall myocardium.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Residual myocytes <60 % by morphometric analysis (or <50 % if estimated), with fibrous replacement of the RV free wall myocardium in ≥1 sample, with or without fatty replacement of tissue on endomyocardial biopsy"

This directly supports the characteristic biopsy finding of fibrous right ventricular wall replacement in ARVC.

⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

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Phenotypes

9

Cardiovascular 7

Ventricular tachycardia HP:0004756

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Patients with AC typically present between the second and the fourth decade of life with palpitations, lightheadedness, or syncope due to ventricular ectopy or (monomorphic) ventricular tachycardia (VT) with left bundle branch block (LBBB) morphology"

This directly supports ventricular tachycardia as a core phenotype.

Syncope HP:0001279

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Patients with AC typically present between the second and the fourth decade of life with palpitations, lightheadedness, or syncope due to ventricular ectopy or (monomorphic) ventricular tachycardia (VT) with left bundle branch block (LBBB) morphology"

This directly supports syncope as a characteristic presenting symptom.

Right ventricular dilatation HP:0005133

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Regional RV akinesia, dyskinesia, or aneurysm ○ And 1 of the following (end diastole): PLAX RVOT ≥32 mm"

The ARVC Task Force Criteria include enlarged right-ventricular outflow tract dimensions among structural right-ventricular abnormalities, supporting right ventricular dilatation.

T-wave inversion HP:0010872

Show evidence (1 reference)

PMID:34191271 SUPPORT Human Clinical

"Patients carrying a PKP2 mutation were younger at diagnosis (p = 0.003), more often had negative T waves in V1-V3 (p = 0.01)"

This directly supports right-precordial T-wave inversion as part of the ARVC ECG phenotype.

Sudden cardiac death HP:0001645

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"However, sudden cardiac death (SCD) may be the first manifestation, often at young age in the concealed stage of disease."

This directly supports sudden cardiac death as a major disease phenotype.

Congestive heart failure HP:0001635

Show evidence (1 reference)

PMID:34191271 SUPPORT Human Clinical

"Patients carrying a PKP2 mutation were younger at diagnosis (p = 0.003), more often had negative T waves in V1-V3 (p = 0.01), had higher left ventricular ejection fraction (p = 0.04), and were less likely to present symptoms of heart failure (p = 0.01)"

This supports heart failure as a clinically relevant phenotype within the ARVC spectrum.

Palpitations HP:0001962

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Patients with AC typically present between the second and the fourth decade of life with palpitations, lightheadedness, or syncope due to ventricular ectopy or (monomorphic) ventricular tachycardia (VT) with left bundle branch block (LBBB) morphology"

This directly identifies palpitations as a typical presenting symptom attributable to ventricular ectopy or VT.

Other 2

Premature ventricular contraction HP:0006682

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

">500 ventricular extrasystoles per 24 h (Holter)"

The Task Force criteria identify frequent ventricular extrasystoles on Holter monitoring as an ARVC arrhythmia criterion.

Epsilon wave HP:0034304

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Epsilon wave (reproducible low-amplitude signals after the end of the QRS complex to onset of the T wave) in right precordial leads (V1, V2, V3)"

This is the major Task Force depolarization criterion for an epsilon wave.

🧬

Genetic Associations

17

PKP2 (Definitive ClinGen gene-disease validity; common causative gene)

Gene: PKP2 hgnc:9024 relationship_type: CAUSATIVE variant_origin: GERMLINE

Show evidence (2 references)

PMID:34191271 SUPPORT Human Clinical

"Ten variants (5 frameshift, 2 nonsense, 2 splicing, and 1 missense) in PKP2 were found in 28 (50%) cases."

This directly supports PKP2 as a common established ARVC gene in this cohort.

CGGV:assertion_6f97b6cd-5225-4076-b67a-2f609908e6fe-2018-03-08T170000.000Z SUPPORT Other

ClinGen classifies the PKP2-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as definitive with autosomal dominant inheritance.

DSP (Reported autosomal-dominant desmosomal association)

Gene: DSP hgnc:3052 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

PMID:18662195 SUPPORT Human Clinical

"ARVC is associated with autosomal dominant mutations of desmosomal proteins, including plakophilin-2 (PKP-2), desmoplakin (DSP), junctional plakoglobin (JUP), desmoglein-2 (DSG-2) and desmocollin-2 (DSC-2) [9–11]."

The review reports autosomal-dominant DSP-associated ARVC. No controlled strong/definitive validity assertion for this exact disease root is available in the local snapshot, so relationship type remains unknown.

DSC2 (Reported autosomal-dominant desmosomal association)

Gene: DSC2 hgnc:3036 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

PMID:18662195 SUPPORT Human Clinical

"ARVC is associated with autosomal dominant mutations of desmosomal proteins, including plakophilin-2 (PKP-2), desmoplakin (DSP), junctional plakoglobin (JUP), desmoglein-2 (DSG-2) and desmocollin-2 (DSC-2) [9–11]."

The review reports autosomal-dominant DSC2-associated ARVC. No controlled strong/definitive validity assertion for this exact disease root is available in the local snapshot, so relationship type remains unknown.

JUP (Reported autosomal-dominant desmosomal association)

Gene: JUP hgnc:6207 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

PMID:18662195 SUPPORT Human Clinical

"ARVC is associated with autosomal dominant mutations of desmosomal proteins, including plakophilin-2 (PKP-2), desmoplakin (DSP), junctional plakoglobin (JUP), desmoglein-2 (DSG-2) and desmocollin-2 (DSC-2) [9–11]."

The review reports autosomal-dominant JUP-associated ARVC while also distinguishing recessive Naxos disease. Relationship type remains unknown without a strong/definitive assertion for this exact disease root.

TMEM43 (Reported non-desmosomal ARVC association)

Gene: TMEM43 hgnc:28472 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Mutations in the non-desmosomal transforming growth factor β3 (TGFβ3), transmembrane protein 43 (TMEM43), desmin (DES), titin (TTN), lamin A/C (LMNA), αT-catenin (CTNNA3), and phospholamban (PLN) genes have been related to index patients and/or families with AC"

The review reports TMEM43 mutations in index cases or families with arrhythmogenic cardiomyopathy; a controlled validity category for this exact disease root is not asserted here.

CDH2 (Limited ClinGen gene-disease validity)

Gene: CDH2 hgnc:1759 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

CGGV:assertion_c7a03805-bf73-4d2d-9756-c666c67be119-2018-07-13T160000.000Z SUPPORT Other

ClinGen classifies the CDH2-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.

CTNNA3 (Limited ClinGen gene-disease validity)

Gene: CTNNA3 hgnc:2511 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

CGGV:assertion_0f1dd946-f2bb-496f-8fea-3dea303e2e76-2019-08-06T160000.000Z SUPPORT Other

ClinGen classifies the CTNNA3-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.

DES (Moderate ClinGen gene-disease validity)

Gene: DES hgnc:2770 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

CGGV:assertion_aef9a60b-a94f-4318-824e-e748c5c20ecb-2018-09-11T160000.000Z SUPPORT Other

ClinGen classifies the DES-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as moderate with autosomal dominant inheritance.

DSG2 (Definitive ClinGen gene-disease validity)

Gene: DSG2 hgnc:3049 relationship_type: CAUSATIVE variant_origin: GERMLINE

Show evidence (1 reference)

CGGV:assertion_f679611d-6e25-45f9-aac3-4a8ad37b1592-2018-09-14T160000.000Z SUPPORT Other

ClinGen classifies the DSG2-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as definitive with autosomal dominant inheritance.

LMNA (Limited ClinGen gene-disease validity)

Gene: LMNA hgnc:6636 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

CGGV:assertion_ef503af9-9d10-4714-848b-34cfa0049c23-2019-09-06T160000.000Z SUPPORT Other

ClinGen classifies the LMNA-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.

MYBPC3 (Limited ClinGen gene-disease validity)

Gene: MYBPC3 hgnc:7551 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

CGGV:assertion_0639d989-8415-425c-ab89-e8a3a0b6ea49-2019-08-06T160000.000Z SUPPORT Other

ClinGen classifies the MYBPC3-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.

MYH7 (Limited ClinGen gene-disease validity)

Gene: MYH7 hgnc:7577 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

CGGV:assertion_0265f091-a67d-4521-b6bd-5a110bd5356f-2019-08-06T160000.000Z SUPPORT Other

ClinGen classifies the MYH7-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.

MYL3 (Limited ClinGen gene-disease validity)

Gene: MYL3 hgnc:7584 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

CGGV:assertion_b1d5e9bf-ca57-445a-a432-27fe221484bf-2019-09-13T160000.000Z SUPPORT Other

ClinGen classifies the MYL3-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.

PLN (Moderate ClinGen gene-disease validity)

Gene: PLN hgnc:9080 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

CGGV:assertion_13027de9-c84a-4968-936b-6356265193a6-2020-12-17T213224.631Z SUPPORT Other

ClinGen classifies the PLN-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as moderate with autosomal dominant inheritance.

SCN5A (Limited ClinGen gene-disease validity)

Gene: SCN5A hgnc:10593 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

CGGV:assertion_3c1cdce2-c8de-442d-b0c4-5936919b310f-2019-06-06T160000.000Z SUPPORT Other

ClinGen classifies the SCN5A-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.

TGFB3 (Limited ClinGen gene-disease validity)

Gene: TGFB3 hgnc:11769 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

CGGV:assertion_36ed9be9-2854-49e5-801c-a8fd65fec98e-2019-08-16T160000.000Z SUPPORT Other

ClinGen classifies the TGFB3-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.

TJP1 (Limited ClinGen gene-disease validity)

Gene: TJP1 hgnc:11827 relationship_type: UNKNOWN variant_origin: GERMLINE

Show evidence (1 reference)

CGGV:assertion_435951df-5a0d-4596-b112-ccd6d6204409-2019-02-08T170000.000Z SUPPORT Other

ClinGen classifies the TJP1-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.

💊

Medical Actions

4

Implantable cardioverter-defibrillator placement

Category: Therapeutic Action: implantable cardioverter-defibrillator placement Ontology label: Implantable Cardioverter-Defibrillator Placement NCIT:C80435

ICD implantation terminates fast ventricular tachycardia or ventricular fibrillation and is the proven life-saving modality for appropriately selected high-risk patients.

Target Phenotypes: Ventricular tachycardia HP:0004756 Sudden cardiac death HP:0001645

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"However, at present ICD implantation is the only proven lifesaving therapeutic modality for fast VT/VF."

This directly supports ICD implantation as the life-saving treatment for fast ventricular tachyarrhythmia.

Antiarrhythmic pharmacotherapy

Category: Therapeutic Action: Pharmacotherapy NCIT:C15986

Agent: sotalol CHEBI:63622 amiodarone CHEBI:2663 flecainide CHEBI:75984

Beta-blockers, sotalol, amiodarone, or flecainide may reduce ventricular arrhythmia burden and symptoms, including as adjuncts intended to reduce ICD shocks.

Target Phenotypes: Ventricular tachycardia HP:0004756 Premature ventricular contraction HP:0006682

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Since ventricular arrhythmias and cardiac arrest occur frequently during or after physical exercise or may be triggered by catecholamines, non-class III antiadrenergic beta-blockers are recommended. In the absence of adequate antiarrhythmic response, sotalol in an appropriate dose is the drug of..."

This directly supports antiarrhythmic pharmacotherapy and names the main drug options used in symptomatic ARVC.

Catheter ablation

Category: Therapeutic Action: cardiac radiofrequency ablation Ontology label: Cardiac Radiofrequency Ablation NCIT:C170884

Endocardial and/or epicardial catheter ablation uses a substrate-based approach to reduce recurrent ventricular tachycardia burden; it does not reverse the underlying cardiomyopathy.

Mechanism Target:

MODULATES Scar-related conduction heterogeneity — Substrate-based ablation modifies regions that sustain scar-related reentry rather than removing all fibrofatty tissue.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"The outcomes of VT ablation are improved with a combined endocardial and epicardial approach, incorporating a substrate-based strategy"

This supports a combined endocardial/epicardial substrate strategy for modifying scar-related reentry.

Target Phenotypes: Ventricular tachycardia HP:0004756 Premature ventricular contraction HP:0006682

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Catheter ablation is an alternative in patients who are refractory to drug treatment and have frequent VT episodes (with a predominantly single morphology)"

This directly supports catheter ablation as a treatment option for recurrent ventricular tachycardia in ARVC.

Avoidance of competitive and endurance exercise

Category: Therapeutic Action: avoid excessive exercise Ontology label: Lifestyle Therapy NCIT:C15900

Restricting competitive and high-intensity endurance exercise reduces mechanical stress and may lower ventricular tachyarrhythmia risk in affected people and pathogenic-variant carriers.

Mechanism Target:

INHIBITS Intercalated-disc adhesion failure — The therapeutic mirror image of the competitive/endurance-sports environmental edge: that exposure EXACERBATES this node by loading an already desmosomally weakened intercalated disc, and withdrawing the exposure removes that load. This is why exercise restriction is disease-modifying rather than merely symptomatic - it acts on the same upstream adhesion-failure node the exposure acts on, not on the arrhythmia readout alone.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"A reversible effect of reduction of sports activities, being a significant decrease in risk for VT or VF, was observed in those individuals who exercised the most (top quartile) [20]."

Reversibility is the key word: withdrawing the exercise exposure lowers arrhythmic risk in the carriers who were most exposed, which is what makes this an intervention on the exposure-sensitive mechanism rather than symptomatic arrhythmia suppression. Scope caveat: the quoted result is a risk reduction measured on the VT/VF readout, so it supports acting on this node by removing its aggravating input; it is not a direct measurement of restored desmosomal adhesion.

Target Phenotypes: Ventricular tachycardia HP:0004756 Sudden cardiac death HP:0001645

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"A reversible effect of reduction of sports activities, being a significant decrease in risk for VT or VF, was observed in those individuals who exercised the most (top quartile) [20]."

Human mutation-carrier data support a reduction in VT/VF risk after reducing sports activity among the highest exercisers.

🌍

Environmental Factors

1

Competitive and endurance sports

Vigorous exercise is an important disease modifier that accelerates progression and increases arrhythmic risk.

Show evidence (2 references)

PMID:24817548 SUPPORT Human Clinical

"Of 87 pathogenic AC mutation carriers, 56 were endurance athletes. Endurance athletes were more likely to have symptoms at young age, fulfil the 2010 TFC, and had lower survival free from VT, ventricular fibrillation (VF), and heart failure."

Human mutation-carrier data directly associate endurance athletics with earlier expression and worse arrhythmia- and heart-failure-free survival.

PMID:24817548 SUPPORT Human Clinical

"Sports participation has been shown to increase the risk of SCD fivefold in AC patients"

This quantifies the association between sports participation and sudden-death risk.

Mechanism Target:

EXACERBATES Intercalated-disc adhesion failure — Endurance and competitive exercise imposes repeated mechanical and haemodynamic load on an already desmosomally weakened intercalated disc. This is the gene-environment interaction that converts a genetically susceptible but structurally near-normal heart into overt disease: the same pathogenic desmosomal variant produces markedly earlier and more severe expression under high exercise exposure, which is why exercise restriction is a disease-modifying intervention rather than merely symptomatic advice.

Show evidence (2 references)

PMID:17030684 SUPPORT Model Organism

"Endurance training accelerated the development of right ventricular dysfunction and arrhythmias in plakoglobin+/- mice."

On a desmosomal (plakoglobin) haploinsufficiency background, endurance training accelerates right-ventricular dysfunction and arrhythmia, showing that exercise acts as a modifier of the adhesion defect rather than as an independent cause. Scope caveat preserved from the same abstract: the accelerated phenotype in these mice was functional and electrophysiologic, and histology and electron microscopy did not identify right-ventricular abnormalities, so this supports exercise acting on the adhesion-failure node but is not evidence for accelerated fibrofatty replacement.

PMID:24817548 SUPPORT Human Clinical

"Of 87 pathogenic AC mutation carriers, 56 were endurance athletes. Endurance athletes were more likely to have symptoms at young age, fulfil the 2010 TFC, and had lower survival free from VT, ventricular fibrillation (VF), and heart failure."

The human counterpart of the mouse result: among carriers of the same class of pathogenic desmosomal variant, endurance exposure shifts onset earlier and worsens arrhythmia-free survival, so the model-organism mechanism is not the sole support for this link.

🔬

Diagnosis

3

Task Force Criteria assessment

Diagnosis is based on international Task Force Criteria integrating imaging, ECG, arrhythmia, tissue, and family-history findings.

clinical assessment NCIT:C124351

Results: Fulfilment of Task Force Criteria supports the diagnosis of ARVC.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Clinical diagnosis is made according to international consensus-based Task Force Criteria"

This directly supports Task Force Criteria-based clinical diagnosis.

Cardiac magnetic resonance imaging

Cardiac MRI is used to evaluate right ventricular structure, function, and tissue abnormalities.

magnetic resonance imaging procedure NCIT:C16809

Results: Structural right ventricular abnormalities support the diagnosis.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Specific evaluations are recommended in all patients suspected of AC: detailed history and family history, physical examination, 12-lead ECG (while off medications), signal averaged ECG, 24-hour Holter monitoring, maximal exercise testing, two-dimensional echocardiography with quantitative wall..."

This directly supports cardiac MRI as part of the standard diagnostic workup.

Genetic testing

Genetic testing helps confirm a familial substrate and identify at-risk relatives.

genetic testing NCIT:C15709

Results: Identification of a pathogenic ARVC-associated variant supports the diagnosis.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"The TFC include six different categories: 1) global and/or regional dysfunction and structural RV alterations, 2) tissue characterisation, 3) depolarisation abnormalities, 4) repolarisation abnormalities, 5) arrhythmias, and 6) family history and genetics."

This directly supports genetics as part of formal ARVC diagnostic assessment.

🩻

Imaging Findings

2

Regional right-ventricular wall-motion abnormality on cardiac MRI

Regional right-ventricular akinesia, dyskinesia, or dyssynchronous contraction on cardiac MRI forms the wall-motion component of the major and minor structural Task Force criteria.

Mri Diagnostic Focal

Regional right-ventricular akinesia, dyskinesia, or dyssynchrony HP:6000664 heart right ventricle UBERON:0002080

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Regional RV akinesia or dyskinesia or dyssynchronous RV contraction"

This is the MRI wall-motion abnormality specified in the Task Force structural criteria.

Right-ventricular dilatation and reduced ejection fraction on cardiac MRI

Increased indexed right-ventricular end-diastolic volume and reduced right-ventricular ejection fraction provide quantitative MRI evidence of structural disease.

Mri Diagnostic

Right-ventricular systolic dysfunction HP:0033118 heart right ventricle UBERON:0002080 Right ventricular dilatation HP:0005133

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"ratio of RVEDV to BSA ≥110 mL/m2 (male) or ≥100 mL/m2 (female), or RV ejection fraction ≤40 %"

These indexed volume and ejection-fraction thresholds define a major MRI structural criterion.

📈

Progression

4

Concealed stage

Structural disease may be absent or minimal, but sudden cardiac death can occur. The four reported stages do not necessarily proceed sequentially.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"AC can present in four clinical stages which do not necessarily proceed from one into the other: 1) concealed stage without or with minimal structural disease, although SCD may occur, 2) overt stage with structural alterations of primarily the right ventricle, and episodes of monomorphic VT, 3)..."

This directly defines the concealed stage and cautions against assuming a fixed sequential course.

Overt right-ventricular stage

Structural abnormalities predominantly affect the right ventricle and are accompanied by episodes of monomorphic ventricular tachycardia.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"AC can present in four clinical stages which do not necessarily proceed from one into the other: 1) concealed stage without or with minimal structural disease, although SCD may occur, 2) overt stage with structural alterations of primarily the right ventricle, and episodes of monomorphic VT, 3)..."

This directly defines the overt stage dominated by right-ventricular structural disease and monomorphic VT.

Overt biventricular stage

More extensive disease has obvious structural involvement of both ventricles.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"AC can present in four clinical stages which do not necessarily proceed from one into the other: 1) concealed stage without or with minimal structural disease, although SCD may occur, 2) overt stage with structural alterations of primarily the right ventricle, and episodes of monomorphic VT, 3)..."

This directly identifies a clinically overt biventricular stage.

End-stage heart failure

Advanced ventricular dysfunction can culminate in heart failure.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"AC can present in four clinical stages which do not necessarily proceed from one into the other: 1) concealed stage without or with minimal structural disease, although SCD may occur, 2) overt stage with structural alterations of primarily the right ventricle, and episodes of monomorphic VT, 3)..."

This directly identifies heart failure as the end-stage presentation.

📊

Prevalence

1

General population

Point Prevalence 20.0–100.0 per 100,000 1–9 per 10,000

Published estimates range from 1 in 5,000 to 1 in 1,000 (20 to 100 per 100,000). The true prevalence is uncertain and may be higher because cases can remain undiagnosed or be misdiagnosed.

Show evidence (2 references)

PMID:24817548 SUPPORT Human Clinical

"Estimations of the prevalence of AC in the general population vary from 1:1000 to 1:5000"

The review provides the numeric range, normalized here to rates per 100,000.

PMID:24817548 SUPPORT Human Clinical

"The real prevalence of AC, however, is unknown and is presumably higher due to many non-diagnosed and misdiagnosed cases."

The review explicitly qualifies the estimate and explains likely underascertainment.

🔀

Differential Diagnoses

5

Conditions with similar clinical presentations that must be differentiated from arrhythmogenic right ventricular cardiomyopathy:

Idiopathic right ventricular outflow tract ventricular tachycardia

Overlapping Features Idiopathic RVOT ventricular tachycardia can mimic ARVC arrhythmias but lacks the familial structural cardiomyopathy substrate.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"In particular, differentiation from idiopathic VT originating from the RV outflow tract (RVOT) can be challenging."

This directly supports idiopathic RVOT VT as an important differential diagnosis.

Cardiac sarcoidosis MONDO:0001707

Overlapping Features Cardiac sarcoidosis can mimic ARVC clinically, on imaging, and even on some molecular markers.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Another disease mimicking AC is cardiac sarcoidosis"

This directly supports cardiac sarcoidosis as a key differential.

Myocarditis MONDO:0004496

Overlapping Features Myocarditis can mimic ARVC clinically and histologically; endomyocardial biopsy may be required to distinguish the disorders.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Myocarditis might also be considered in the differential diagnosis. In general, endomyocardial biopsy is required to distinguish myocarditis from AC."

This directly identifies myocarditis as a differential and describes the role of biopsy in distinguishing it from ARVC.

Brugada syndrome MONDO:0015263

Overlapping Features Brugada syndrome can overlap through right-precordial ECG abnormalities or right-ventricular arrhythmias but lacks the defining fibrofatty cardiomyopathy substrate.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"Brugada syndrome with similar electrocardiographic or RV arrhythmias"

The review explicitly identifies Brugada syndrome as a rare differential because of overlapping ECG or right-ventricular arrhythmias.

Dilated cardiomyopathy MONDO:0005021

Overlapping Features Advanced ARVC can mimic dilated cardiomyopathy, but arrhythmia-first presentation should prompt ARVC consideration.

Show evidence (1 reference)

PMID:24817548 SUPPORT Human Clinical

"AC may also mimic dilated cardiomyopathy (DCM), especially in the more advanced stages of disease."

This directly supports dilated cardiomyopathy as a differential diagnosis.

📊

Related Datasets

3

Pericardial fluid microRNAs in patients with arrhythmogenic right ventricular cardiomyopathy or ischemic heart disease geo:GSE164490

Pericardial fluid is enriched by biologically active molecules of cardiovascular origin including microRNAs. Investigation of the disease-specific extracellular microRNAs could shed light on the molecular processes underlying disease development. Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart disease characterized by life-threatening arrhythmias and progressive heart failure development. The current data about the association between microRNAs and ARVC development are limited.

human BULK RNA SEQ n=9

PMID:33816578

Identified by GEO DataSets index search for arrhythmogenic right ventricular cardiomyopathy (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.

Myocardial transcriptome analysis of human arrhythmogenic right ventricular cardiomyopathy (ARVC) geo:GSE29819

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy primarily of the right ventricle characterized through fibrofatty replacement of cardiomyocytes. The genetic etiology in ARVC patients is most commonly caused by dominant inheritance and high genetic heterogeneity. Though histological examinations of ARVC affected human myocardium reveals fibrolipomatous replacement, the molecular mechanisms leading to loss of cardiomyocytes are largely unknown.

human MICROARRAY n=38

PMID:22085907

Identified by GEO DataSets index search for arrhythmogenic right ventricular cardiomyopathy (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.

PKP2 Gene Therapy Improves Heart Function and Reduces Mortality in a Pkp2-deficient Mouse Model of Arrhythmogenic Right Ventricular Cardiomyopathy geo:GSE253226

BULK RNA SEQ n=112

PMID:38499690

Identified by GEO DataSets index search for arrhythmogenic right ventricular cardiomyopathy (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.

🧫

Experimental Models

1

Heterozygous plakoglobin-deficient (plakoglobin+/-) mouse OTHER

Mice heterozygous for a plakoglobin (Jup) null allele, modelling the desmosomal haploinsufficiency mechanism of ARVC. By ten months they show increased right-ventricular volume, reduced right-ventricular function and spontaneous ventricular ectopy with preserved left-ventricular size and function, and isolated perfused hearts show ventricular tachycardia of right-ventricular origin with prolonged right-ventricular conduction times. The model is the principal in vivo demonstration that endurance training accelerates the ARVC phenotype on a desmosomal-deficiency background, which is why it anchors the exercise exposure edge in this entry. Important scope limit: histology and electron microscopy did not identify right-ventricular abnormalities in affected animals, so the model recapitulates the functional, conduction and arrhythmic arms of the disease but NOT the fibrofatty replacement that defines its histopathology - it must not be cited as evidence for accelerated fibrofatty remodelling.

Organism

house mouse NCBITaxon:10090

Publication

PMID:17030684

Pathograph links

Intercalated-disc adhesion failure Plakoglobin haploinsufficiency reproduces the desmosomal adhesion defect in vivo, and endurance training accelerates its functional and arrhythmic consequences - the model system behind the exercise EXACERBATES edge on this node.

Show evidence (1 reference)

PMID:17030684 SUPPORT Model Organism

"Heterozygous plakoglobin deficiency provokes ARVC. Manifestation of the phenotype is accelerated by endurance training."

States both halves of what this model contributes: desmosomal haploinsufficiency is sufficient to provoke the phenotype, and exercise accelerates its manifestation.

Show evidence (1 reference)

PMID:17030684 SUPPORT Model Organism

"Ten-month-old heterozygous plakoglobin-deficient mice (plakoglobin+/-) had increased right ventricular volume, reduced right ventricular function, and spontaneous ventricular ectopy (all P<0.05). Left ventricular size and function were not altered."

Documents the model's defining right-ventricular-selective phenotype, which is what makes it a model of ARVC specifically rather than of generalised cardiomyopathy.

{ }

Source YAML

click to show

name: arrhythmogenic right ventricular cardiomyopathy
creation_date: '2026-04-14T12:00:00Z'
category: Mendelian
description: >-
  Arrhythmogenic right ventricular cardiomyopathy is a hereditary
  cardiomyopathy characterized by ventricular arrhythmias, right ventricular
  and sometimes left ventricular dysfunction, and progressive fibrofatty
  replacement of cardiomyocytes. The disease is most often driven by defects in
  desmosomal adhesion proteins at the cardiomyocyte intercalated disc, causing
  mechanical uncoupling, electrical conduction abnormalities, and an
  arrhythmogenic substrate that can lead to syncope or sudden cardiac death.
disease_term:
  preferred_term: arrhythmogenic right ventricular cardiomyopathy
  term:
    id: MONDO:0016587
    label: arrhythmogenic right ventricular cardiomyopathy
classifications:
  mechanistic_category:
  - classification_value: desmosomopathy
    notes: >-
      Applies to the predominant desmosomal-gene forms of ARVC
      (PKP2, DSP, DSG2, DSC2, JUP). A minority of ARVC is caused by
      non-desmosomal loci (e.g. TMEM43, LMNA, PLN, DES, CTNNA3, TGFB3),
      which this mechanistic category does not cover.
mappings:
  mondo_mappings:
  - term:
      id: MONDO:0016342
      label: familial isolated arrhythmogenic right ventricular dysplasia
    mapping_predicate: skos:narrowMatch
    mapping_source: MONDO
    mapping_justification: >
      MONDO:0016342 is the familial, isolated (non-syndromic) presentation of
      ARVC, defined as intersection_of MONDO:0016587 plus RO:0000053
      MONDO:0021128 (has an isolated presentation), and is_a the MONDO:0016587
      anchor of this entry. It is the direct parent of the numbered ARVD series
      mapped below. This entry curates the familial autosomal-dominant
      desmosomal disease it denotes, so the term is covered here. narrowMatch
      rather than exactMatch because the MONDO:0016587 anchor also subsumes the
      syndromic cardiocutaneous recessive forms (Naxos, Carvajal), which are
      curated as their own entries and which the "isolated presentation"
      restriction of MONDO:0016342 excludes.
  - term:
      id: MONDO:0011459
      label: arrhythmogenic right ventricular dysplasia 5
    mapping_predicate: skos:narrowMatch
    mapping_source: MONDO
    mapping_justification: >
      ARVD5 is defined as the TMEM43 form (intersection_of RO:0004003
      HGNC:28472) and sits under MONDO:0016342 (familial isolated ARVD), which
      is_a the MONDO:0016587 anchor of this entry. This entry curates TMEM43
      (hgnc:28472), so the child term is covered here. narrowMatch because the
      anchor subsumes the whole numbered ARVD series.
  - term:
      id: MONDO:0012434
      label: arrhythmogenic right ventricular dysplasia 10
    mapping_predicate: skos:narrowMatch
    mapping_source: MONDO
    mapping_justification: >
      ARVD10 is defined as the DSG2 form (intersection_of RO:0004003 HGNC:3049)
      and sits under MONDO:0016342, which is_a the MONDO:0016587 anchor of this
      entry. This entry curates DSG2 (hgnc:3049), so the child term is covered
      here. narrowMatch because the anchor subsumes the whole numbered series.
  - term:
      id: MONDO:0012506
      label: arrhythmogenic right ventricular dysplasia 11
    mapping_predicate: skos:narrowMatch
    mapping_source: MONDO
    mapping_justification: >
      ARVD11 is defined as the DSC2 form (intersection_of RO:0004003 HGNC:3036)
      and sits under MONDO:0016342, which is_a the MONDO:0016587 anchor of this
      entry. This entry curates DSC2 (hgnc:3036), so the child term is covered
      here. narrowMatch because the anchor subsumes the whole numbered series.
gene_sets:
- gene_set: MYGENESET:KEGG_ARRHYTHMOGENIC_RIGHT_VENTRICULAR_CARDIOMYOPATHY_ARVC
  relationship: CANONICAL_PATHWAY
  note: >-
    KEGG ARVC pathway.
synonyms:
- arrhythmogenic right ventricular dysplasia/cardiomyopathy
- ARVC
- arrhythmogenic cardiomyopathy
references:
- reference: PMID:20301310
  title: "Arrhythmogenic Right Ventricular Cardiomyopathy Overview."
  tags:
  - GeneReviews
mechanistic_hypotheses:
- hypothesis_group_id: anti_dsg2_causal_injury_driver_or_amplifier
  hypothesis_label: Anti-DSG2 Causal Injury Driver or Amplifier
  status: EMERGING
  description: >-
    Anti-DSG2 antibodies may causally worsen genetically vulnerable myocardium
    either as antecedent drivers or as injury-dependent amplifiers. Candidate
    mechanisms are direct impairment of junctional adhesion or electrical
    coupling and Fc-receptor- or complement-dependent injury. A signal that
    merely follows tissue damage without antigen-specific functional activity
    is the null, biomarker-only alternative and refutes this causal hypothesis.
    DAMP-mediated innate activation remains a separately tested possible
    upstream or parallel branch rather than a presumed linear cascade. Current
    evidence does not warrant wiring this emerging hypothesis to a causal
    pathophysiology edge, defining a clinical biomarker, or proposing an
    immune-directed treatment.
  evidence:
  - reference: PMID:42406223
    reference_title: >-
      From inflammation to inheritance: rethinking myocarditis as the first
      signal of desmosomal cardiomyopathy.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      While these observations support a possible role for autoimmunity, the
      causal contribution of these autoantibodies to myocardial injury and
      disease progression remains incompletely established and constitutes a
      proposed rather than confirmed model.
    explanation: >-
      The seed narrative review explicitly identifies the causal autoimmune
      interpretation as a working model while emphasizing that it remains
      unconfirmed. This supports testing an emerging causal hypothesis, not
      treating an injury-associated antibody signal as part of that hypothesis.
  - reference: PMID:30239670
    reference_title: >-
      An autoantibody identifies arrhythmogenic right ventricular
      cardiomyopathy and participates in its pathogenesis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We identified anti-DSG2 antibodies in 12/12 and 25/25 definite ARVC
      cohorts and 7/8 borderline subjects.
    explanation: >-
      The original small discovery and validation cohorts support antibody
      occurrence in clinically defined ARVC. The study lacked myocarditis and
      inflammatory-cardiomyopathy comparators, so these case-control results do
      not establish disease specificity, temporal order, or causality.
  - reference: PMID:30239670
    reference_title: >-
      An autoantibody identifies arrhythmogenic right ventricular
      cardiomyopathy and participates in its pathogenesis.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      antibodies caused gap junction dysfunction, a common feature of ARVC, in
      vitro.
    explanation: >-
      Purified IgG from two ARVC patients and a commercial anti-DSG2 antibody
      provide an initial functional signal in human iPSC-derived
      cardiomyocytes. The experiment did not use antigen-specific depletion and
      add-back for patient IgG or establish Fc or complement dependence,
      necessity, or sufficiency in vivo.
  - reference: PMID:41351822
    reference_title: >-
      Anti-desmoglein-2 autoantibodies do not discriminate between UK boxer
      dogs with and without arrhythmogenic right ventricular cardiomyopathy.
    supports: REFUTE
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Serum anti-DSG2 autoantibodies were detected in all dogs, bar one healthy
      dog.
    explanation: >-
      In an independent 40-Boxer cohort, anti-DSG2 was nearly ubiquitous across
      healthy, preclinical-ARVC, and clinical-ARVC groups. This fails to
      reproduce the original Boxer-model disease-specificity anchor. It does
      not by itself exclude a pathogenic human antibody subset or an
      injury-dependent amplifier, but directly refutes using Boxer seropositivity
      as evidence that anti-DSG2 distinguishes affected from unaffected animals.
  - reference: PMID:42160918
    reference_title: >-
      Evaluation of anti-desmoglein-2 antibodies and cardiac biomarkers in
      Boxer dogs with arrhythmogenic right ventricular cardiomyopathy.
    supports: REFUTE
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Anti-desmoglein-2 antibody concentrations did not differ between groups by
      either method (enzyme-linked immunosorbent assay: P=0.687; Western blot:
      P=0.293).
    explanation: >-
      A separate prospective study of 28 affected and 24 screened-control
      Boxers found poor anti-DSG2 discrimination by ELISA and Western blot,
      while troponin and NT-proBNP performed substantially better and tracked
      ventricular premature-complex burden. This independently refutes the
      model-specific diagnostic premise and favors conventional injury or
      dysfunction markers, while remaining non-decisive about a causal human
      antibody subset.
  - reference: PMID:37450050
    reference_title: >-
      Catalytic antibodies in arrhythmogenic cardiomyopathy patients cleave
      desmoglein 2 and N-cadherin and impair cardiomyocyte cohesion.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      IgG fractions were purified from 15 AC patients and 4 healthy controls.
    explanation: >-
      The donor series was small, comprised only DSP- or PKP2-variant
      arrhythmogenic cardiomyopathy cases, and pooled IgG from four healthy
      controls. It included no inflammatory cardiac comparator, serial samples,
      or clinical test of whether the activity preceded injury.
  - reference: PMID:37450050
    reference_title: >-
      Catalytic antibodies in arrhythmogenic cardiomyopathy patients cleave
      desmoglein 2 and N-cadherin and impair cardiomyocyte cohesion.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Immunostainings revealed that autoantibodies against ICD proteins are
      prevalent in AC and most autoantibody fractions have catalytic properties
      and cleave the ICD adhesion molecules DSG2 and N-cadherin, thereby
      reducing cadherin interactions as revealed by AFM.
    explanation: >-
      In biochemical and murine atrial cell-line assays, 11 of 15 IgG fractions
      cleaved recombinant DSG2, six reduced cellular cohesion, and p38
      inhibition rescued cohesion for selected fractions. The fractions also
      targeted N-cadherin, the study could not detect anti-DSG2 binding by its
      ELISAs, and it used no antigen-specific adsorption, monoclonal
      reconstruction, or intact-animal transfer.
  - reference: PMID:42219531
    reference_title: >-
      Autoantibodies in Patients With Arrhythmogenic Cardiomyopathy Activate
      GSK-3β, Resulting in a Loss of Cardiomyocyte Cohesion.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Three out of six ACM patients derived IgGs that reduced cardiomyocyte
      cohesion.
    explanation: >-
      Total polyclonal IgG from only half of the six broader arrhythmogenic
      cardiomyopathy donors reduced cohesion in cell and tissue assays, and
      healthy-relative IgG also stained intercalated discs. GSK-3β inhibition
      rescued the responder-IgG phenotype, but the study did not use
      DSG2-specific depletion and add-back, a sequence-defined monoclonal,
      epitope rescue, or intact-animal transfer. It therefore supports a
      reproducible functional signal in a subset, not an anti-DSG2-specific
      causal axis or a treatment claim.
  - reference: PMID:39597880
    reference_title: >-
      Prevalence and Correlates of Anti-DSG2 Antibodies in Arrhythmogenic Right
      Ventricular Cardiomyopathy and Myocarditis: Immunological Insights from a
      Multicenter Study.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Anti-DSG2-ab titer was not different between ARVC and myocarditis/DCM
      patients (48% anti-DSG-ab positive).
    explanation: >-
      In 77 ARVC cases, 91 myocarditis or DCM cases, 27 systemic
      immune-mediated disease cases, and 50 controls, 56% of ARVC cases were
      positive, but titers did not distinguish ARVC from myocarditis or DCM and
      anti-DSG2 positivity had no ARVC clinical correlates. This argues against
      treating the antibody as ARVC-specific or as an established mediator.
  - reference: url:https://www.ebi.ac.uk/europepmc/webservices/rest/PMC13256025/fullTextXML
    reference_title: "Introduction"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Anti-DSG2 antibody levels were not associated with major arrhythmic
      events.
    explanation: >-
      In 101 definite ARVC cases, antibody levels separated cases from 37
      selected Ebstein-anomaly or Eisenmenger-syndrome controls and 31 healthy
      controls. A separately derived higher threshold correlated with cardiac
      death or transplantation but not arrhythmic events. The single-centre
      study lacked longitudinal antibody measurements and myocarditis or DCM
      comparators, so its favorable internally derived cutoffs do not reverse
      the comparator-rich PMID:39597880 finding or establish temporal order,
      disease specificity, or causality.
  - reference: url:https://www.ebi.ac.uk/europepmc/webservices/rest/PMC13256025/fullTextXML
    reference_title: "Introduction"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      As comparisons were limited to right ventricular disease controls,
      diagnostic specificity relative to other non-ischaemic cardiomyopathies
      more commonly entering the ARVC remains to be established.
    explanation: >-
      The investigators explicitly bound their specificity claim to the
      selected comparison set. This supports testing antibody utility in
      harmonized, prospectively thresholded cohorts that include myocarditis,
      DCM, and other non-ischaemic cardiomyopathies rather than treating the
      internally estimated specificity as a general ARVC property.
  - reference: PMID:32114801
    reference_title: >-
      Evidence From Family Studies for Autoimmunity in Arrhythmogenic Right
      Ventricular Cardiomyopathy: Associations of Circulating Anti-Heart and
      Anti-Intercalated Disk Autoantibodies With Disease Severity and Family
      History.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Longitudinal studies are needed to clarify whether they may predict ARVC
      development in healthy relatives or if they be a result of manifest
      ARVC.
    explanation: >-
      Anti-heart and anti-intercalated-disc antibodies were enriched in ARVC
      families and associated cross-sectionally with severity features, but the
      investigators explicitly could not distinguish antecedent autoimmunity
      from a response to manifest disease.
  - reference: PMID:35764120
    reference_title: High frequency of anti-DSG 2 antibodies in post COVID-19 serum samples.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Of note, 29.3% of the post COVID-19 infection samples demonstrated a
      signal higher than the 90th percentile of the control population and
      8.7% were higher than the median found in ARVC patients.
    explanation: >-
      Sustained anti-DSG2 signals after COVID-19 show that antibody elevation
      can follow a non-ARVC inflammatory or injury context. The study did not
      phenotype cardiac injury deeply, so it establishes neither a common
      mechanism nor harmlessness, but materially weakens disease specificity.
  - reference: PMID:19635863
    reference_title: >-
      Myocyte necrosis underlies progressive myocardial dystrophy in mouse
      dsg2-related arrhythmogenic right ventricular cardiomyopathy.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      We demonstrate for the first time that myocyte necrosis is the key
      initiator of myocardial injury, triggering progressive myocardial damage,
      including an inflammatory response and massive calcification within the
      myocardium, followed by injury repair with fibrous tissue replacement,
      and myocardial atrophy.
    explanation: >-
      A transgenic Dsg2 model supports primary structural injury followed by
      inflammation and fibrosis. It does not test DAMP necessity or
      autoantibodies, and therefore supports a plausible injury-first branch
      without establishing the proposed adaptive immune sequence in humans.
parents:
- hereditary disease
- cardiomyopathy
prevalence:
- population: General population
  measure_type: POINT_PREVALENCE
  prevalence_class: BAND_1_5_PER_10000
  rate_low: 20.0
  rate_high: 100.0
  notes: >-
    Published estimates range from 1 in 5,000 to 1 in 1,000 (20 to 100 per
    100,000). The true prevalence is uncertain and may be higher because cases
    can remain undiagnosed or be misdiagnosed.
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Estimations of the prevalence of AC in the general population vary from
      1:1000 to 1:5000
    explanation: >-
      The review provides the numeric range, normalized here to rates per
      100,000.
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The real prevalence of AC, however, is unknown and is presumably higher
      due to many non-diagnosed and misdiagnosed cases.
    explanation: >-
      The review explicitly qualifies the estimate and explains likely
      underascertainment.
progression:
- phase: Concealed stage
  notes: >-
    Structural disease may be absent or minimal, but sudden cardiac death can
    occur. The four reported stages do not necessarily proceed sequentially.
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      AC can present in four clinical stages which do not necessarily proceed
      from one into the other: 1) concealed stage without or with minimal
      structural disease, although SCD may occur, 2) overt stage with structural
      alterations of primarily the right ventricle, and episodes of monomorphic
      VT, 3) overt stage with obvious structural biventricular involvement, and
      4) the end-stage of the disease with heart failure [1, 26, 27].
    explanation: >-
      This directly defines the concealed stage and cautions against assuming a
      fixed sequential course.
- phase: Overt right-ventricular stage
  notes: >-
    Structural abnormalities predominantly affect the right ventricle and are
    accompanied by episodes of monomorphic ventricular tachycardia.
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      AC can present in four clinical stages which do not necessarily proceed
      from one into the other: 1) concealed stage without or with minimal
      structural disease, although SCD may occur, 2) overt stage with structural
      alterations of primarily the right ventricle, and episodes of monomorphic
      VT, 3) overt stage with obvious structural biventricular involvement, and
      4) the end-stage of the disease with heart failure [1, 26, 27].
    explanation: >-
      This directly defines the overt stage dominated by right-ventricular
      structural disease and monomorphic VT.
- phase: Overt biventricular stage
  notes: >-
    More extensive disease has obvious structural involvement of both
    ventricles.
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      AC can present in four clinical stages which do not necessarily proceed
      from one into the other: 1) concealed stage without or with minimal
      structural disease, although SCD may occur, 2) overt stage with structural
      alterations of primarily the right ventricle, and episodes of monomorphic
      VT, 3) overt stage with obvious structural biventricular involvement, and
      4) the end-stage of the disease with heart failure [1, 26, 27].
    explanation: >-
      This directly identifies a clinically overt biventricular stage.
- phase: End-stage heart failure
  notes: >-
    Advanced ventricular dysfunction can culminate in heart failure.
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      AC can present in four clinical stages which do not necessarily proceed
      from one into the other: 1) concealed stage without or with minimal
      structural disease, although SCD may occur, 2) overt stage with structural
      alterations of primarily the right ventricle, and episodes of monomorphic
      VT, 3) overt stage with obvious structural biventricular involvement, and
      4) the end-stage of the disease with heart failure [1, 26, 27].
    explanation: >-
      This directly identifies heart failure as the end-stage presentation.
inheritance:
- name: Autosomal dominant inheritance
  inheritance_term:
    preferred_term: Autosomal dominant inheritance
    term:
      id: HP:0000006
      label: Autosomal dominant inheritance
  penetrance: INCOMPLETE
  expressivity: VARIABLE
  description: >-
    Most familial ARVC is inherited in an autosomal dominant fashion with
    reduced penetrance and variable expressivity.
  evidence:
  - reference: PMID:18662195
    reference_title: >-
      Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy
      caused by plakophilin-2 mutations.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      ARVC is associated with autosomal dominant mutations of desmosomal
      proteins, including plakophilin-2 (PKP-2), desmoplakin (DSP), junctional
      plakoglobin (JUP), desmoglein-2 (DSG-2) and desmocollin-2 (DSC-2)
      [9–11].
    explanation: >-
      This directly supports autosomal-dominant inheritance across the
      canonical desmosomal gene spectrum.
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      incorporating genetic results in AC risk stratification is hampered by
      incomplete penetrance and an extremely variable clinical expression.
      Mutation carriers may present with SCD but can also remain without signs
      and symptoms of the disease into old age.
    explanation: >-
      This directly supports the incomplete penetrance and variable
      expressivity that characterise the inherited, autosomal dominant ARVC
      substrate.
pathophysiology:
- name: Intercalated-disc adhesion failure
  biological_scale: CELLULAR
  mechanism_confidence: ESTABLISHED
  description: >-
    Pathogenic variation in core desmosomal genes disrupts mechanical
    cell-cell adhesion at cardiomyocyte intercalated discs. PKP2, DSP, DSG2,
    DSC2, and JUP form the canonical desmosomal core represented here; the
    gene-level validity annotations below preserve the strength of each
    available assertion.
  genes:
  - preferred_term: PKP2
    term:
      id: hgnc:9024
      label: PKP2
  - preferred_term: DSP
    term:
      id: hgnc:3052
      label: DSP
  - preferred_term: DSG2
    term:
      id: hgnc:3049
      label: DSG2
  - preferred_term: DSC2
    term:
      id: hgnc:3036
      label: DSC2
  - preferred_term: JUP
    term:
      id: hgnc:6207
      label: JUP
  cell_types:
  - preferred_term: cardiac muscle cell
    term:
      id: CL:0000746
      label: cardiac muscle cell
  biological_processes:
  - preferred_term: cell-cell adhesion
    term:
      id: GO:0098609
      label: cell-cell adhesion
    modifier: DECREASED
  locations:
  - preferred_term: myocardium
    term:
      id: UBERON:0002349
      label: myocardium
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Desmosomal dysfunction due to a gene mutation may give rise to loss of
      mechanical cell-cell adhesion
    explanation: >-
      This directly supports loss of mechanical cardiomyocyte adhesion as the
      proximal lesion.
  downstream:
  - target: Gap-junction and sodium-channel remodeling
    description: >-
      Desmosomal dysfunction changes connexin43 and Nav1.5 abundance or
      localization at the intercalated disc.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:24817548
      reference_title: >-
        Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
        management.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Desmosomal dysfunction due to a gene mutation may give rise to loss of
        mechanical cell-cell adhesion, and leads to down-regulation and/or
        altered distribution of other intercalated disk proteins, i.e. gap
        junction proteins (Connexin43) and sodium channels (Nav1.5) [43–45].
      explanation: >-
        This directly links desmosomal dysfunction to secondary remodeling of
        gap-junction and sodium-channel proteins.
  - target: Cardiomyocyte apoptosis and loss
    description: >-
      Mechanical dissociation under repeated myocardial stress can progress to
      cardiomyocyte injury, apoptosis, and loss.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Mechanical dissociation of cardiomyocytes under repetitive wall stress
    evidence:
    - reference: PMID:16823493
      reference_title: >-
        Suppression of canonical Wnt/beta-catenin signaling by nuclear
        plakoglobin recapitulates phenotype of arrhythmogenic right ventricular
        cardiomyopathy.
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        Heterozygous DP-deficient mice exhibited excess adipocytes and fibrosis
        in the myocardium, increased myocyte apoptosis, cardiac dysfunction,
        and ventricular arrhythmias, thus recapitulating the phenotype of human
        ARVC.
      explanation: >-
        A desmoplakin-deficient mouse model supports apoptosis downstream of
        desmosomal deficiency, but the edge remains indirect for human ARVC.
  - target: Nuclear plakoglobin and canonical Wnt suppression
    description: >-
      Desmosomal disruption can redistribute plakoglobin to the nucleus and
      reduce canonical Wnt/beta-catenin signaling.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Release and nuclear redistribution of plakoglobin after desmosomal disruption
    evidence:
    - reference: PMID:16823493
      reference_title: >-
        Suppression of canonical Wnt/beta-catenin signaling by nuclear
        plakoglobin recapitulates phenotype of arrhythmogenic right ventricular
        cardiomyopathy.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: >-
        suppression of DP expression leads to nuclear localization of the
        desmosomal protein plakoglobin and a 2-fold reduction in canonical
        Wnt/beta-catenin signaling through Tcf/Lef1 transcription factors.
      explanation: >-
        Desmoplakin knockdown directly produced nuclear plakoglobin and reduced
        canonical Wnt signaling in cultured atrial myocytes.
- name: Gap-junction and sodium-channel remodeling
  biological_scale: MOLECULAR
  mechanism_confidence: ESTABLISHED
  description: >-
    Reduced connexin43 expression or intercalated-disc localization impairs
    electrical coupling, while altered Nav1.5 distribution slows ventricular
    conduction. Electrical remodeling can precede overt fibrofatty disease.
  cell_types:
  - preferred_term: cardiac muscle cell
    term:
      id: CL:0000746
      label: cardiac muscle cell
  biological_processes:
  - preferred_term: gap junction assembly
    term:
      id: GO:0016264
      label: gap junction assembly
    modifier: DECREASED
  - preferred_term: transmembrane transport
    term:
      id: GO:0055085
      label: transmembrane transport
    modifier: DECREASED
  evidence:
  - reference: PMID:18662195
    reference_title: >-
      Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy
      caused by plakophilin-2 mutations.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Reduced connexin43 expression and localization to the intercalated disk
      occurs in heterozygous human PKP-2 mutations, potentially explaining the
      delayed conduction and propensity to develop arrhythmias seen in this
      disease.
    explanation: >-
      Human myocardial tissue directly demonstrates connexin43 remodeling in
      heterozygous PKP2-related ARVC.
  downstream:
  - target: Arrhythmogenic slow-conduction substrate
    description: >-
      Electrical uncoupling and reduced sodium current create slow,
      heterogeneous activation that predisposes to ventricular tachyarrhythmia.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:24817548
      reference_title: >-
        Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
        management.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        These alterations give rise to electrical cell-cell uncoupling and slow
        conduction, respectively, thereby providing a substrate for early
        activation delay resulting in ventricular tachyarrhythmia, a hallmark
        of AC [5, 12, 46, 47].
      explanation: >-
        The review explicitly links intercalated-disc electrical remodeling to
        slow conduction and the ventricular tachyarrhythmia substrate.
- name: Nuclear plakoglobin and canonical Wnt suppression
  biological_scale: MOLECULAR
  mechanism_confidence: PROVISIONAL
  description: >-
    Nuclear plakoglobin can suppress canonical Wnt/beta-catenin signaling and
    increase adipogenic and fibrogenic gene expression. This branch is retained
    as provisional because its direct evidence is primarily experimental.
  biological_processes:
  - preferred_term: Wnt signaling pathway
    term:
      id: GO:0016055
      label: Wnt signaling pathway
    modifier: DECREASED
  - preferred_term: fat cell differentiation
    term:
      id: GO:0045444
      label: fat cell differentiation
    modifier: INCREASED
  evidence:
  - reference: PMID:16823493
    reference_title: >-
      Suppression of canonical Wnt/beta-catenin signaling by nuclear
      plakoglobin recapitulates phenotype of arrhythmogenic right ventricular
      cardiomyopathy.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      suppression of DP expression leads to nuclear localization of the
      desmosomal protein plakoglobin and a 2-fold reduction in canonical
      Wnt/beta-catenin signaling through Tcf/Lef1 transcription factors. The
      ensuing phenotype is increased expression of adipogenic and fibrogenic
      genes and accumulation of fat droplets.
    explanation: >-
      This directly supports the experimental Wnt-suppression branch and its
      adipogenic and fibrogenic transcriptional consequences.
  downstream:
  - target: Fibrofatty myocardial replacement
    description: >-
      Increased adipogenic and fibrogenic programs promote the characteristic
      fibro-adipose tissue phenotype.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:16823493
      reference_title: >-
        Suppression of canonical Wnt/beta-catenin signaling by nuclear
        plakoglobin recapitulates phenotype of arrhythmogenic right ventricular
        cardiomyopathy.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: >-
        The ensuing phenotype is increased expression of adipogenic and
        fibrogenic genes and accumulation of fat droplets.
      explanation: >-
        The cell model directly links Wnt suppression to adipogenic and
        fibrogenic expression and fat accumulation.
- name: Cardiomyocyte apoptosis and loss
  biological_scale: CELLULAR
  mechanism_confidence: PROVISIONAL
  description: >-
    Repeated mechanical injury in desmosome-deficient myocardium can cause
    cardiomyocyte apoptosis and depletion, creating space for replacement
    tissue.
  cell_types:
  - preferred_term: cardiac muscle cell
    term:
      id: CL:0000746
      label: cardiac muscle cell
  evidence:
  - reference: PMID:16823493
    reference_title: >-
      Suppression of canonical Wnt/beta-catenin signaling by nuclear
      plakoglobin recapitulates phenotype of arrhythmogenic right ventricular
      cardiomyopathy.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Heterozygous DP-deficient mice exhibited excess adipocytes and fibrosis
      in the myocardium, increased myocyte apoptosis, cardiac dysfunction, and
      ventricular arrhythmias, thus recapitulating the phenotype of human ARVC.
    explanation: >-
      Desmoplakin-deficient mice support myocyte apoptosis as part of the
      fibrofatty cardiomyopathy phenotype.
  downstream:
  - target: Fibrofatty myocardial replacement
    description: >-
      Loss of cardiomyocytes is followed by fibrous and adipose replacement of
      the depleted myocardium.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Clearance of injured cardiomyocytes and repair by fibro-adipose tissue
    evidence:
    - reference: PMID:18662195
      reference_title: >-
        Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy
        caused by plakophilin-2 mutations.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Fibrofatty replacement of myocardium is likely a later phenomenon in the
        majority of patients with ARVC, representing a reaction to more
        complete mechanical dissociation as a result of desmosomal failure, or
        an additional molecular mechanism such as Wnt signalling [20].
      explanation: >-
        Human-tissue interpretation places fibrofatty replacement after more
        complete mechanical dissociation, while leaving the exact repair steps
        indirect.
- name: Fibrofatty myocardial replacement
  biological_scale: TISSUE
  mechanism_confidence: ESTABLISHED
  conforms_to: "cardiomyopathy_maladaptive_remodeling#Ventricular Remodeling"
  description: >-
    Progressive replacement of myocardium by fibrous and adipose tissue is the
    defining structural lesion. It often predominates in the right ventricle
    but may extend to the left ventricle.
  cell_types:
  - preferred_term: cardiac muscle cell
    term:
      id: CL:0000746
      label: cardiac muscle cell
  - preferred_term: fibroblast of cardiac tissue
    term:
      id: CL:0002548
      label: fibroblast of cardiac tissue
  - preferred_term: adipocyte
    term:
      id: CL:0000136
      label: adipocyte
  biological_processes:
  - preferred_term: tissue remodeling
    term:
      id: GO:0048771
      label: tissue remodeling
    modifier: INCREASED
  locations:
  - preferred_term: heart right ventricle
    term:
      id: UBERON:0002080
      label: heart right ventricle
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Arrhythmogenic cardiomyopathy (AC), also known as arrhythmogenic right
      ventricular dysplasia/cardiomyopathy (ARVD/C), is a hereditary disease
      characterised by ventricular arrhythmias, right ventricular and/or left
      ventricular dysfunction, and fibrofatty replacement of cardiomyocytes.
    explanation: >-
      This directly identifies fibrofatty cardiomyocyte replacement as a
      defining human disease feature.
  downstream:
  - target: Scar-related conduction heterogeneity
    description: >-
      Fibrofatty architectural disruption forces discontinuous activation
      through zig-zag pathways and creates load mismatch.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:24817548
      reference_title: >-
        Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
        management.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Presumably, at a later stage myocyte loss and fibrofatty replacement
        will have a major impact on tissue architecture, giving rise to zig-zag
        conduction pathways and load mismatch, further contributing to enhanced
        activation delay [32, 48].
      explanation: >-
        This directly connects the structural lesion to discontinuous
        conduction and activation delay.
  - target: Progressive ventricular contractile dysfunction
    description: >-
      Loss of functional myocardium and adverse chamber remodeling impair
      ventricular pump function.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Loss of contractile myocardium and adverse ventricular remodeling
    evidence:
    - reference: PMID:24817548
      reference_title: >-
        Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
        management.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Arrhythmogenic cardiomyopathy (AC), also known as arrhythmogenic right
        ventricular dysplasia/cardiomyopathy (ARVD/C), is a hereditary disease
        characterised by ventricular arrhythmias, right ventricular and/or left
        ventricular dysfunction, and fibrofatty replacement of cardiomyocytes.
      explanation: >-
        The defining clinical description co-occurs with fibrofatty replacement
        and ventricular dysfunction; the omitted remodeling steps are stated
        explicitly as intermediates.
- name: Scar-related conduction heterogeneity
  biological_scale: TISSUE
  mechanism_confidence: ESTABLISHED
  description: >-
    Fibrofatty tissue architecture creates discontinuous, slow activation and
    load mismatch, adding a later structural substrate to the earlier
    intercalated-disc electrical phenotype.
  locations:
  - preferred_term: myocardium
    term:
      id: UBERON:0002349
      label: myocardium
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Presumably, at a later stage myocyte loss and fibrofatty replacement will
      have a major impact on tissue architecture, giving rise to zig-zag
      conduction pathways and load mismatch, further contributing to enhanced
      activation delay [32, 48].
    explanation: >-
      This directly supports a late scar-related conduction mechanism.
  downstream:
  - target: Arrhythmogenic slow-conduction substrate
    description: >-
      Zig-zag activation and load mismatch reinforce conduction delay and
      reentry.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:18662195
      reference_title: >-
        Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy
        caused by plakophilin-2 mutations.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Areas of slow conduction are one predisposing factor for re-entrant
        ventricular arrhythmias, which are seen in this disease and responsible
        in this patient group for sudden cardiac death.
      explanation: >-
        Human ARVC observations connect slow-conduction areas to reentrant
        ventricular arrhythmias.
- name: Arrhythmogenic slow-conduction substrate
  biological_scale: TISSUE
  mechanism_confidence: ESTABLISHED
  description: >-
    Early intercalated-disc electrical remodeling and later fibrofatty
    architectural remodeling converge on slow, heterogeneous conduction that
    supports ventricular ectopy, reentry, and malignant tachyarrhythmia.
  locations:
  - preferred_term: heart right ventricle
    term:
      id: UBERON:0002080
      label: heart right ventricle
  evidence:
  - reference: PMID:18662195
    reference_title: >-
      Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy
      caused by plakophilin-2 mutations.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The decrease of connexin43 among ARVC patients assessed in this study
      provides an explanation for the conduction delay and resultant
      arrhythmias seen in ARVC.
    explanation: >-
      Human myocardial findings support delayed conduction as the substrate
      for arrhythmia.
  downstream:
  - target: Ventricular tachycardia
    description: >-
      Slow, heterogeneous ventricular activation supports reentrant
      ventricular tachycardia.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:24817548
      reference_title: >-
        Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
        management.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        These alterations give rise to electrical cell-cell uncoupling and slow
        conduction, respectively, thereby providing a substrate for early
        activation delay resulting in ventricular tachyarrhythmia, a hallmark
        of AC [5, 12, 46, 47].
      explanation: >-
        The review directly links slow conduction and activation delay to
        ventricular tachyarrhythmia.
  - target: Premature ventricular contraction
    description: >-
      The arrhythmogenic myocardium produces frequent ventricular ectopy.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:24817548
      reference_title: >-
        Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
        management.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        >500 ventricular extrasystoles per 24 h (Holter)
      explanation: >-
        Frequent ventricular extrasystoles are an explicit Task Force
        arrhythmia criterion.
  - target: Palpitations
    description: >-
      Ventricular ectopy or tachycardia is perceived clinically as
      palpitations.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Ventricular ectopy or tachycardia perceived as an abnormal heartbeat
    evidence:
    - reference: PMID:24817548
      reference_title: >-
        Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
        management.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Patients with AC typically present between the second and the fourth
        decade of life with palpitations, lightheadedness, or syncope due to
        ventricular ectopy or (monomorphic) ventricular tachycardia (VT) with
        left bundle branch block (LBBB) morphology
      explanation: >-
        This directly attributes the presenting symptoms to ventricular ectopy
        or monomorphic VT.
  - target: Syncope
    description: >-
      Sustained ventricular arrhythmia can cause transient cerebral
      hypoperfusion and syncope.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Transient loss of cardiac output and cerebral hypoperfusion during arrhythmia
    evidence:
    - reference: PMID:24817548
      reference_title: >-
        Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
        management.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Patients with AC typically present between the second and the fourth
        decade of life with palpitations, lightheadedness, or syncope due to
        ventricular ectopy or (monomorphic) ventricular tachycardia (VT) with
        left bundle branch block (LBBB) morphology
      explanation: >-
        The review explicitly attributes syncope to ventricular ectopy or VT.
  - target: Sudden cardiac death
    description: >-
      Reentrant ventricular arrhythmia can progress through fast VT or
      ventricular fibrillation to sudden cardiac death.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Fast ventricular tachycardia or ventricular fibrillation causing cardiac arrest
    evidence:
    - reference: PMID:18662195
      reference_title: >-
        Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy
        caused by plakophilin-2 mutations.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Areas of slow conduction are one predisposing factor for re-entrant
        ventricular arrhythmias, which are seen in this disease and responsible
        in this patient group for sudden cardiac death.
      explanation: >-
        Human ARVC data link slow-conduction reentry to sudden cardiac death.
  - target: Epsilon wave
    description: >-
      Delayed terminal right-ventricular activation can appear as an epsilon
      wave on the surface ECG.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Delayed terminal activation of right-ventricular myocardium
    evidence:
    - reference: PMID:18662195
      reference_title: >-
        Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy
        caused by plakophilin-2 mutations.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Patient 3 showed epsilon waves, while Patients 1 and 2 were found to
        have late potentials on signal-averaged ECG, reflecting slow electrical
        conduction over the anterior right ventricle.
      explanation: >-
        The patient series relates epsilon waves and late potentials to slow
        right-ventricular conduction.
  - target: T-wave inversion
    description: >-
      Right-precordial T-wave inversion is a repolarization manifestation of
      diseased right-ventricular myocardium, but its precise causal bridge from
      the slow-conduction substrate is not fully resolved.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:24817548
      reference_title: >-
        Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
        management.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Inverted T waves in right precordial leads (V1, V2, V3) or beyond in
        individuals >14 years of age
      explanation: >-
        The Task Force criteria establish the ECG manifestation; the
        mechanistic intermediates linking it to the substrate remain uncertain.
- name: Progressive ventricular contractile dysfunction
  biological_scale: TISSUE
  mechanism_confidence: ESTABLISHED
  description: >-
    Loss and replacement of contractile myocardium impair right-ventricular and
    sometimes left-ventricular function, producing chamber remodeling and
    eventual heart failure.
  locations:
  - preferred_term: heart right ventricle
    term:
      id: UBERON:0002080
      label: heart right ventricle
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      AC can present in four clinical stages which do not necessarily proceed
      from one into the other: 1) concealed stage without or with minimal
      structural disease, although SCD may occur, 2) overt stage with structural
      alterations of primarily the right ventricle, and episodes of monomorphic
      VT, 3) overt stage with obvious structural biventricular involvement, and
      4) the end-stage of the disease with heart failure [1, 26, 27].
    explanation: >-
      The clinical staging evidence supports progression from ventricular
      structural involvement to biventricular disease and end-stage failure.
  downstream:
  - target: Right ventricular dilatation
    description: >-
      Loss of contractile myocardium and adverse remodeling enlarge the right
      ventricular chamber.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Loss of functional myocardium and adverse chamber remodeling
    evidence:
    - reference: PMID:24817548
      reference_title: >-
        Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
        management.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        ratio of RVEDV to BSA ≥110 mL/m2 (male) or ≥100 mL/m2 (female), or RV
        ejection fraction ≤40 %
      explanation: >-
        The MRI major criterion jointly captures increased right-ventricular
        end-diastolic volume and reduced ejection fraction.
  - target: Congestive heart failure
    description: >-
      Advanced ventricular pump dysfunction culminates in symptomatic heart
      failure.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Reduced cardiac output and systemic or pulmonary venous congestion
    evidence:
    - reference: PMID:24817548
      reference_title: >-
        Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
        management.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        the end-stage of the disease with heart failure
      explanation: >-
        This directly identifies heart failure as the end-stage clinical
        consequence.
histopathology:
- name: Fibrous replacement of right ventricular free wall myocardium
  diagnostic: true
  description: >-
    Endomyocardial biopsy can show marked loss of right-ventricular myocytes
    with fibrous replacement of the free wall myocardium.
  finding_term:
    preferred_term: fibrous replacement of right ventricular free wall myocardium
    term:
      id: NCIT:C3044
      label: Fibrosis
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Residual myocytes <60 % by morphometric analysis (or <50 % if estimated),
      with fibrous replacement of the RV free wall myocardium in ≥1 sample,
      with or without fatty replacement of tissue on endomyocardial biopsy
    explanation: >-
      This directly supports the characteristic biopsy finding of fibrous right
      ventricular wall replacement in ARVC.
phenotypes:
- category: Cardiovascular
  name: Ventricular tachycardia
  description: >-
    Monomorphic ventricular tachycardia with left bundle branch block
    morphology is a classic presentation.
  phenotype_term:
    preferred_term: Ventricular tachycardia
    term:
      id: HP:0004756
      label: Ventricular tachycardia
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Patients with AC typically present between the second and the fourth
      decade of life with palpitations, lightheadedness, or syncope due to
      ventricular ectopy or (monomorphic) ventricular tachycardia (VT) with
      left bundle branch block (LBBB) morphology
    explanation: >-
      This directly supports ventricular tachycardia as a core phenotype.
- category: Cardiovascular
  name: Syncope
  description: >-
    Syncope commonly reflects transient cerebral hypoperfusion from malignant
    ventricular arrhythmia.
  phenotype_term:
    preferred_term: Syncope
    term:
      id: HP:0001279
      label: Syncope
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Patients with AC typically present between the second and the fourth
      decade of life with palpitations, lightheadedness, or syncope due to
      ventricular ectopy or (monomorphic) ventricular tachycardia (VT) with
      left bundle branch block (LBBB) morphology
    explanation: >-
      This directly supports syncope as a characteristic presenting symptom.
- category: Cardiovascular
  name: Right ventricular dilatation
  description: >-
    Progressive structural disease produces right ventricular enlargement and
    wall-motion abnormalities.
  phenotype_term:
    preferred_term: Right ventricular dilatation
    term:
      id: HP:0005133
      label: Right ventricular dilatation
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Regional RV akinesia, dyskinesia, or aneurysm  ○ And 1 of the following (end diastole): PLAX RVOT ≥32 mm
    explanation: >-
      The ARVC Task Force Criteria include enlarged right-ventricular outflow
      tract dimensions among structural right-ventricular abnormalities,
      supporting right ventricular dilatation.
- category: Cardiovascular
  name: T-wave inversion
  description: >-
    T-wave inversion in right precordial leads is part of the diagnostic ECG
    phenotype.
  phenotype_term:
    preferred_term: T-wave inversion
    term:
      id: HP:0010872
      label: T-wave inversion
  evidence:
  - reference: PMID:34191271
    reference_title: >-
      Pathogenic variants in plakophilin-2 gene (PKP2) are associated with
      better survival in arrhythmogenic right ventricular cardiomyopathy.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Patients carrying a PKP2 mutation were younger at diagnosis (p = 0.003),
      more often had negative T waves in V1-V3 (p = 0.01)
    explanation: >-
      This directly supports right-precordial T-wave inversion as part of the
      ARVC ECG phenotype.
- category: Cardiovascular
  name: Sudden cardiac death
  description: >-
    Sudden death may be the first manifestation, including in the concealed
    stage.
  phenotype_term:
    preferred_term: Sudden cardiac death
    term:
      id: HP:0001645
      label: Sudden cardiac death
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      However, sudden cardiac death (SCD) may be the first manifestation, often
      at young age in the concealed stage of disease.
    explanation: >-
      This directly supports sudden cardiac death as a major disease phenotype.
- category: Cardiovascular
  name: Congestive heart failure
  description: >-
    Later disease stages can progress to clinically significant heart failure.
  phenotype_term:
    preferred_term: Congestive heart failure
    term:
      id: HP:0001635
      label: Congestive heart failure
  evidence:
  - reference: PMID:34191271
    reference_title: >-
      Pathogenic variants in plakophilin-2 gene (PKP2) are associated with
      better survival in arrhythmogenic right ventricular cardiomyopathy.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Patients carrying a PKP2 mutation were younger at diagnosis (p = 0.003),
      more often had negative T waves in V1-V3 (p = 0.01), had higher left
      ventricular ejection fraction (p = 0.04), and were less likely to present
      symptoms of heart failure (p = 0.01)
    explanation: >-
      This supports heart failure as a clinically relevant phenotype within the
      ARVC spectrum.
- category: Cardiovascular
  name: Premature ventricular contraction
  description: >-
    Frequent ventricular extrasystoles are a characteristic arrhythmic
    manifestation and form part of the Task Force diagnostic criteria.
  phenotype_term:
    preferred_term: Premature ventricular contraction
    term:
      id: HP:0006682
      label: Premature ventricular contraction
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      >500 ventricular extrasystoles per 24 h (Holter)
    explanation: >-
      The Task Force criteria identify frequent ventricular extrasystoles on
      Holter monitoring as an ARVC arrhythmia criterion.
- category: Cardiovascular
  name: Palpitations
  description: >-
    Palpitations commonly accompany ventricular ectopy or monomorphic
    ventricular tachycardia.
  phenotype_term:
    preferred_term: Palpitations
    term:
      id: HP:0001962
      label: Palpitations
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Patients with AC typically present between the second and the fourth
      decade of life with palpitations, lightheadedness, or syncope due to
      ventricular ectopy or (monomorphic) ventricular tachycardia (VT) with
      left bundle branch block (LBBB) morphology
    explanation: >-
      This directly identifies palpitations as a typical presenting symptom
      attributable to ventricular ectopy or VT.
- category: Cardiovascular
  name: Epsilon wave
  diagnostic: true
  description: >-
    A reproducible low-amplitude signal after the QRS complex in right
    precordial leads is a major depolarization criterion.
  phenotype_term:
    preferred_term: Epsilon wave
    term:
      id: HP:0034304
      label: Epsilon wave
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Epsilon wave (reproducible low-amplitude signals after the end of the QRS
      complex to onset of the T wave) in right precordial leads (V1, V2, V3)
    explanation: >-
      This is the major Task Force depolarization criterion for an epsilon
      wave.
biochemical: []
genetic:
- name: PKP2
  gene_term:
    preferred_term: PKP2
    term:
      id: hgnc:9024
      label: PKP2
  association: Definitive ClinGen gene-disease validity; common causative gene
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  evidence:
  - reference: PMID:34191271
    reference_title: >-
      Pathogenic variants in plakophilin-2 gene (PKP2) are associated with
      better survival in arrhythmogenic right ventricular cardiomyopathy.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Ten variants (5 frameshift, 2 nonsense, 2 splicing, and 1 missense) in PKP2 were found in 28 (50%) cases.
    explanation: >-
      This directly supports PKP2 as a common established ARVC gene in this
      cohort.
  - reference: CGGV:assertion_6f97b6cd-5225-4076-b67a-2f609908e6fe-2018-03-08T170000.000Z
    reference_title: "PKP2 / arrhythmogenic right ventricular cardiomyopathy (Definitive)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "PKP2 | HGNC:9024 | arrhythmogenic right ventricular cardiomyopathy | MONDO:0016587 | AD | Definitive"
    explanation: ClinGen classifies the PKP2-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as definitive with autosomal dominant inheritance.
- name: DSP
  gene_term:
    preferred_term: DSP
    term:
      id: hgnc:3052
      label: DSP
  association: Reported autosomal-dominant desmosomal association
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: PMID:18662195
    reference_title: >-
      Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy
      caused by plakophilin-2 mutations.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      ARVC is associated with autosomal dominant mutations of desmosomal
      proteins, including plakophilin-2 (PKP-2), desmoplakin (DSP), junctional
      plakoglobin (JUP), desmoglein-2 (DSG-2) and desmocollin-2 (DSC-2)
      [9–11].
    explanation: >-
      The review reports autosomal-dominant DSP-associated ARVC. No controlled
      strong/definitive validity assertion for this exact disease root is
      available in the local snapshot, so relationship type remains unknown.
- name: DSC2
  gene_term:
    preferred_term: DSC2
    term:
      id: hgnc:3036
      label: DSC2
  association: Reported autosomal-dominant desmosomal association
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: PMID:18662195
    reference_title: >-
      Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy
      caused by plakophilin-2 mutations.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      ARVC is associated with autosomal dominant mutations of desmosomal
      proteins, including plakophilin-2 (PKP-2), desmoplakin (DSP), junctional
      plakoglobin (JUP), desmoglein-2 (DSG-2) and desmocollin-2 (DSC-2)
      [9–11].
    explanation: >-
      The review reports autosomal-dominant DSC2-associated ARVC. No controlled
      strong/definitive validity assertion for this exact disease root is
      available in the local snapshot, so relationship type remains unknown.
- name: JUP
  gene_term:
    preferred_term: JUP
    term:
      id: hgnc:6207
      label: JUP
  association: Reported autosomal-dominant desmosomal association
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: PMID:18662195
    reference_title: >-
      Abnormal connexin43 in arrhythmogenic right ventricular cardiomyopathy
      caused by plakophilin-2 mutations.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      ARVC is associated with autosomal dominant mutations of desmosomal
      proteins, including plakophilin-2 (PKP-2), desmoplakin (DSP), junctional
      plakoglobin (JUP), desmoglein-2 (DSG-2) and desmocollin-2 (DSC-2)
      [9–11].
    explanation: >-
      The review reports autosomal-dominant JUP-associated ARVC while also
      distinguishing recessive Naxos disease. Relationship type remains
      unknown without a strong/definitive assertion for this exact disease
      root.
- name: TMEM43
  gene_term:
    preferred_term: TMEM43
    term:
      id: hgnc:28472
      label: TMEM43
  association: Reported non-desmosomal ARVC association
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Mutations in the non-desmosomal transforming growth factor β3 (TGFβ3),
      transmembrane protein 43 (TMEM43), desmin (DES), titin (TTN), lamin A/C
      (LMNA), αT-catenin (CTNNA3), and phospholamban (PLN) genes have been
      related to index patients and/or families with AC
    explanation: >-
      The review reports TMEM43 mutations in index cases or families with
      arrhythmogenic cardiomyopathy; a controlled validity category for this
      exact disease root is not asserted here.
- name: CDH2
  gene_term:
    preferred_term: CDH2
    term:
      id: hgnc:1759
      label: CDH2
  association: Limited ClinGen gene-disease validity
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: CGGV:assertion_c7a03805-bf73-4d2d-9756-c666c67be119-2018-07-13T160000.000Z
    reference_title: "CDH2 / arrhythmogenic right ventricular cardiomyopathy (Limited)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "CDH2 | HGNC:1759 | arrhythmogenic right ventricular cardiomyopathy | MONDO:0016587 | AD | Limited"
    explanation: ClinGen classifies the CDH2-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.
- name: CTNNA3
  gene_term:
    preferred_term: CTNNA3
    term:
      id: hgnc:2511
      label: CTNNA3
  association: Limited ClinGen gene-disease validity
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: CGGV:assertion_0f1dd946-f2bb-496f-8fea-3dea303e2e76-2019-08-06T160000.000Z
    reference_title: "CTNNA3 / arrhythmogenic right ventricular cardiomyopathy (Limited)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "CTNNA3 | HGNC:2511 | arrhythmogenic right ventricular cardiomyopathy | MONDO:0016587 | AD | Limited"
    explanation: ClinGen classifies the CTNNA3-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.
- name: DES
  gene_term:
    preferred_term: DES
    term:
      id: hgnc:2770
      label: DES
  association: Moderate ClinGen gene-disease validity
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: CGGV:assertion_aef9a60b-a94f-4318-824e-e748c5c20ecb-2018-09-11T160000.000Z
    reference_title: "DES / arrhythmogenic right ventricular cardiomyopathy (Moderate)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "DES | HGNC:2770 | arrhythmogenic right ventricular cardiomyopathy | MONDO:0016587 | AD | Moderate"
    explanation: ClinGen classifies the DES-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as moderate with autosomal dominant inheritance.
- name: DSG2
  gene_term:
    preferred_term: DSG2
    term:
      id: hgnc:3049
      label: DSG2
  association: Definitive ClinGen gene-disease validity
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  evidence:
  - reference: CGGV:assertion_f679611d-6e25-45f9-aac3-4a8ad37b1592-2018-09-14T160000.000Z
    reference_title: "DSG2 / arrhythmogenic right ventricular cardiomyopathy (Definitive)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "DSG2 | HGNC:3049 | arrhythmogenic right ventricular cardiomyopathy | MONDO:0016587 | AD | Definitive"
    explanation: ClinGen classifies the DSG2-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as definitive with autosomal dominant inheritance.
- name: LMNA
  gene_term:
    preferred_term: LMNA
    term:
      id: hgnc:6636
      label: LMNA
  association: Limited ClinGen gene-disease validity
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: CGGV:assertion_ef503af9-9d10-4714-848b-34cfa0049c23-2019-09-06T160000.000Z
    reference_title: "LMNA / arrhythmogenic right ventricular cardiomyopathy (Limited)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "LMNA | HGNC:6636 | arrhythmogenic right ventricular cardiomyopathy | MONDO:0016587 | AD | Limited"
    explanation: ClinGen classifies the LMNA-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.
- name: MYBPC3
  gene_term:
    preferred_term: MYBPC3
    term:
      id: hgnc:7551
      label: MYBPC3
  association: Limited ClinGen gene-disease validity
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: CGGV:assertion_0639d989-8415-425c-ab89-e8a3a0b6ea49-2019-08-06T160000.000Z
    reference_title: "MYBPC3 / arrhythmogenic right ventricular cardiomyopathy (Limited)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "MYBPC3 | HGNC:7551 | arrhythmogenic right ventricular cardiomyopathy | MONDO:0016587 | AD | Limited"
    explanation: ClinGen classifies the MYBPC3-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.
- name: MYH7
  gene_term:
    preferred_term: MYH7
    term:
      id: hgnc:7577
      label: MYH7
  association: Limited ClinGen gene-disease validity
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: CGGV:assertion_0265f091-a67d-4521-b6bd-5a110bd5356f-2019-08-06T160000.000Z
    reference_title: "MYH7 / arrhythmogenic right ventricular cardiomyopathy (Limited)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "MYH7 | HGNC:7577 | arrhythmogenic right ventricular cardiomyopathy | MONDO:0016587 | AD | Limited"
    explanation: ClinGen classifies the MYH7-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.
- name: MYL3
  gene_term:
    preferred_term: MYL3
    term:
      id: hgnc:7584
      label: MYL3
  association: Limited ClinGen gene-disease validity
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: CGGV:assertion_b1d5e9bf-ca57-445a-a432-27fe221484bf-2019-09-13T160000.000Z
    reference_title: "MYL3 / arrhythmogenic right ventricular cardiomyopathy (Limited)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "MYL3 | HGNC:7584 | arrhythmogenic right ventricular cardiomyopathy | MONDO:0016587 | AD | Limited"
    explanation: ClinGen classifies the MYL3-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.
- name: PLN
  gene_term:
    preferred_term: PLN
    term:
      id: hgnc:9080
      label: PLN
  association: Moderate ClinGen gene-disease validity
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: CGGV:assertion_13027de9-c84a-4968-936b-6356265193a6-2020-12-17T213224.631Z
    reference_title: "PLN / arrhythmogenic right ventricular cardiomyopathy (Moderate)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "PLN | HGNC:9080 | arrhythmogenic right ventricular cardiomyopathy | MONDO:0016587 | AD | Moderate"
    explanation: ClinGen classifies the PLN-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as moderate with autosomal dominant inheritance.
- name: SCN5A
  gene_term:
    preferred_term: SCN5A
    term:
      id: hgnc:10593
      label: SCN5A
  association: Limited ClinGen gene-disease validity
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: CGGV:assertion_3c1cdce2-c8de-442d-b0c4-5936919b310f-2019-06-06T160000.000Z
    reference_title: "SCN5A / arrhythmogenic right ventricular cardiomyopathy (Limited)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "SCN5A | HGNC:10593 | arrhythmogenic right ventricular cardiomyopathy | MONDO:0016587 | AD | Limited"
    explanation: ClinGen classifies the SCN5A-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.
- name: TGFB3
  gene_term:
    preferred_term: TGFB3
    term:
      id: hgnc:11769
      label: TGFB3
  association: Limited ClinGen gene-disease validity
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: CGGV:assertion_36ed9be9-2854-49e5-801c-a8fd65fec98e-2019-08-16T160000.000Z
    reference_title: "TGFB3 / arrhythmogenic right ventricular cardiomyopathy (Limited)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "TGFB3 | HGNC:11769 | arrhythmogenic right ventricular cardiomyopathy | MONDO:0016587 | AD | Limited"
    explanation: ClinGen classifies the TGFB3-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.
- name: TJP1
  gene_term:
    preferred_term: TJP1
    term:
      id: hgnc:11827
      label: TJP1
  association: Limited ClinGen gene-disease validity
  relationship_type: UNKNOWN
  variant_origin: GERMLINE
  evidence:
  - reference: CGGV:assertion_435951df-5a0d-4596-b112-ccd6d6204409-2019-02-08T170000.000Z
    reference_title: "TJP1 / arrhythmogenic right ventricular cardiomyopathy (Limited)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "TJP1 | HGNC:11827 | arrhythmogenic right ventricular cardiomyopathy | MONDO:0016587 | AD | Limited"
    explanation: ClinGen classifies the TJP1-arrhythmogenic right ventricular cardiomyopathy gene-disease relationship as limited with autosomal dominant inheritance.
environmental:
- name: Competitive and endurance sports
  exposure_term:
    preferred_term: strenuous exercise
    term:
      id: ECTO:6000031
      label: exposure to strenuous exercise
  description: >-
    Vigorous exercise is an important disease modifier that accelerates
    progression and increases arrhythmic risk.
  effect: EXACERBATES
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Of 87 pathogenic AC mutation carriers, 56 were endurance athletes.
      Endurance athletes were more likely to have symptoms at young age, fulfil
      the 2010 TFC, and had lower survival free from VT, ventricular fibrillation
      (VF), and heart failure.
    explanation: >-
      Human mutation-carrier data directly associate endurance athletics with
      earlier expression and worse arrhythmia- and heart-failure-free survival.
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Sports participation has been shown to increase the risk of SCD fivefold
      in AC patients
    explanation: >-
      This quantifies the association between sports participation and
      sudden-death risk.
  influences_mechanisms:
  - target: Intercalated-disc adhesion failure
    environmental_effect: EXACERBATES
    causal_link_type: DIRECT
    description: >-
      Endurance and competitive exercise imposes repeated mechanical and
      haemodynamic load on an already desmosomally weakened intercalated disc.
      This is the gene-environment interaction that converts a genetically
      susceptible but structurally near-normal heart into overt disease:
      the same pathogenic desmosomal variant produces markedly earlier and
      more severe expression under high exercise exposure, which is why
      exercise restriction is a disease-modifying intervention rather than
      merely symptomatic advice.
    evidence:
    - reference: PMID:17030684
      reference_title: >-
        Age- and training-dependent development of arrhythmogenic right
        ventricular cardiomyopathy in heterozygous plakoglobin-deficient mice.
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        Endurance training accelerated the development of right ventricular
        dysfunction and arrhythmias in plakoglobin+/- mice.
      explanation: >-
        On a desmosomal (plakoglobin) haploinsufficiency background, endurance
        training accelerates right-ventricular dysfunction and arrhythmia,
        showing that exercise acts as a modifier of the adhesion defect rather
        than as an independent cause. Scope caveat preserved from the same
        abstract: the accelerated phenotype in these mice was functional and
        electrophysiologic, and histology and electron microscopy did not
        identify right-ventricular abnormalities, so this supports exercise
        acting on the adhesion-failure node but is not evidence for accelerated
        fibrofatty replacement.
    - reference: PMID:24817548
      reference_title: >-
        Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
        management.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Of 87 pathogenic AC mutation carriers, 56 were endurance athletes.
        Endurance athletes were more likely to have symptoms at young age, fulfil
        the 2010 TFC, and had lower survival free from VT, ventricular fibrillation
        (VF), and heart failure.
      explanation: >-
        The human counterpart of the mouse result: among carriers of the same
        class of pathogenic desmosomal variant, endurance exposure shifts onset
        earlier and worsens arrhythmia-free survival, so the model-organism
        mechanism is not the sole support for this link.
treatments:
- name: Implantable cardioverter-defibrillator placement
  action_category: THERAPEUTIC
  therapeutic_modality: DEVICE
  treatment_term:
    preferred_term: implantable cardioverter-defibrillator placement
    term:
      id: NCIT:C80435
      label: Implantable Cardioverter-Defibrillator Placement
  description: >-
    ICD implantation terminates fast ventricular tachycardia or ventricular
    fibrillation and is the proven life-saving modality for appropriately
    selected high-risk patients.
  target_phenotypes:
  - preferred_term: Ventricular tachycardia
    term:
      id: HP:0004756
      label: Ventricular tachycardia
  - preferred_term: Sudden cardiac death
    term:
      id: HP:0001645
      label: Sudden cardiac death
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      However, at present ICD implantation is the only proven lifesaving
      therapeutic modality for fast VT/VF.
    explanation: >-
      This directly supports ICD implantation as the life-saving treatment for
      fast ventricular tachyarrhythmia.
- name: Antiarrhythmic pharmacotherapy
  action_category: THERAPEUTIC
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: sotalol
      term:
        id: CHEBI:63622
        label: sotalol
    - preferred_term: amiodarone
      term:
        id: CHEBI:2663
        label: amiodarone
    - preferred_term: flecainide
      term:
        id: CHEBI:75984
        label: flecainide
  description: >-
    Beta-blockers, sotalol, amiodarone, or flecainide may reduce ventricular
    arrhythmia burden and symptoms, including as adjuncts intended to reduce ICD
    shocks.
  target_phenotypes:
  - preferred_term: Ventricular tachycardia
    term:
      id: HP:0004756
      label: Ventricular tachycardia
  - preferred_term: Premature ventricular contraction
    term:
      id: HP:0006682
      label: Premature ventricular contraction
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Since ventricular arrhythmias and cardiac arrest occur frequently during
      or after physical exercise or may be triggered by catecholamines,
      non-class III antiadrenergic beta-blockers are recommended. In the
      absence of adequate antiarrhythmic response, sotalol in an appropriate
      dose is the drug of first choice. Alternatively, amiodarone and
      flecainide have been reported to be useful
    explanation: >-
      This directly supports antiarrhythmic pharmacotherapy and names the main
      drug options used in symptomatic ARVC.
- name: Catheter ablation
  action_category: THERAPEUTIC
  therapeutic_modality: SURGERY
  treatment_term:
    preferred_term: cardiac radiofrequency ablation
    term:
      id: NCIT:C170884
      label: Cardiac Radiofrequency Ablation
  description: >-
    Endocardial and/or epicardial catheter ablation uses a substrate-based
    approach to reduce recurrent ventricular tachycardia burden; it does not
    reverse the underlying cardiomyopathy.
  target_phenotypes:
  - preferred_term: Ventricular tachycardia
    term:
      id: HP:0004756
      label: Ventricular tachycardia
  - preferred_term: Premature ventricular contraction
    term:
      id: HP:0006682
      label: Premature ventricular contraction
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Catheter ablation is an alternative in patients who are refractory to
      drug treatment and have frequent VT episodes (with a predominantly single
      morphology)
    explanation: >-
      This directly supports catheter ablation as a treatment option for
      recurrent ventricular tachycardia in ARVC.
  target_mechanisms:
  - target: Scar-related conduction heterogeneity
    treatment_effect: MODULATES
    description: >-
      Substrate-based ablation modifies regions that sustain scar-related
      reentry rather than removing all fibrofatty tissue.
    evidence:
    - reference: PMID:24817548
      reference_title: >-
        Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
        management.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        The outcomes of VT ablation are improved with a combined endocardial
        and epicardial approach, incorporating a substrate-based strategy
      explanation: >-
        This supports a combined endocardial/epicardial substrate strategy for
        modifying scar-related reentry.
- name: Avoidance of competitive and endurance exercise
  action_category: THERAPEUTIC
  therapeutic_modality: BEHAVIORAL
  treatment_term:
    preferred_term: avoid excessive exercise
    term:
      id: NCIT:C15900
      label: Lifestyle Therapy
  description: >-
    Restricting competitive and high-intensity endurance exercise reduces
    mechanical stress and may lower ventricular tachyarrhythmia risk in
    affected people and pathogenic-variant carriers.
  target_phenotypes:
  - preferred_term: Ventricular tachycardia
    term:
      id: HP:0004756
      label: Ventricular tachycardia
  - preferred_term: Sudden cardiac death
    term:
      id: HP:0001645
      label: Sudden cardiac death
  target_mechanisms:
  - target: Intercalated-disc adhesion failure
    treatment_effect: INHIBITS
    description: >-
      The therapeutic mirror image of the competitive/endurance-sports
      environmental edge: that exposure EXACERBATES this node by loading an
      already desmosomally weakened intercalated disc, and withdrawing the
      exposure removes that load. This is why exercise restriction is
      disease-modifying rather than merely symptomatic - it acts on the same
      upstream adhesion-failure node the exposure acts on, not on the
      arrhythmia readout alone.
    evidence:
    - reference: PMID:24817548
      reference_title: >-
        Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
        management.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        A reversible effect of reduction of sports activities, being a
        significant decrease in risk for VT or VF, was observed in those
        individuals who exercised the most (top quartile) [20].
      explanation: >-
        Reversibility is the key word: withdrawing the exercise exposure lowers
        arrhythmic risk in the carriers who were most exposed, which is what
        makes this an intervention on the exposure-sensitive mechanism rather
        than symptomatic arrhythmia suppression. Scope caveat: the quoted
        result is a risk reduction measured on the VT/VF readout, so it
        supports acting on this node by removing its aggravating input; it is
        not a direct measurement of restored desmosomal adhesion.
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      A reversible effect of reduction of sports activities, being a
      significant decrease in risk for VT or VF, was observed in those
      individuals who exercised the most (top quartile) [20].
    explanation: >-
      Human mutation-carrier data support a reduction in VT/VF risk after
      reducing sports activity among the highest exercisers.
imaging_findings:
- name: Regional right-ventricular wall-motion abnormality on cardiac MRI
  modality: MRI
  imaging_finding_term:
    preferred_term: Regional right-ventricular akinesia, dyskinesia, or dyssynchrony
    term:
      id: HP:6000664
      label: Right ventricular regional wall motion abnormality
  description: >-
    Regional right-ventricular akinesia, dyskinesia, or dyssynchronous
    contraction on cardiac MRI forms the wall-motion component of the major and
    minor structural Task Force criteria.
  located_in:
    preferred_term: heart right ventricle
    term:
      id: UBERON:0002080
      label: heart right ventricle
  spatial_extent: FOCAL
  diagnostic: true
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Regional RV akinesia or dyskinesia or dyssynchronous RV contraction
    explanation: >-
      This is the MRI wall-motion abnormality specified in the Task Force
      structural criteria.
- name: Right-ventricular dilatation and reduced ejection fraction on cardiac MRI
  modality: MRI
  imaging_finding_term:
    preferred_term: Right-ventricular systolic dysfunction
    term:
      id: HP:0033118
      label: Abnormal right ventricular function
  description: >-
    Increased indexed right-ventricular end-diastolic volume and reduced
    right-ventricular ejection fraction provide quantitative MRI evidence of
    structural disease.
  located_in:
    preferred_term: heart right ventricle
    term:
      id: UBERON:0002080
      label: heart right ventricle
  phenotype_term:
    preferred_term: Right ventricular dilatation
    term:
      id: HP:0005133
      label: Right ventricular dilatation
  diagnostic: true
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      ratio of RVEDV to BSA ≥110 mL/m2 (male) or ≥100 mL/m2 (female), or RV
      ejection fraction ≤40 %
    explanation: >-
      These indexed volume and ejection-fraction thresholds define a major MRI
      structural criterion.
experimental_models:
- name: Heterozygous plakoglobin-deficient (plakoglobin+/-) mouse
  description: >-
    Mice heterozygous for a plakoglobin (Jup) null allele, modelling the
    desmosomal haploinsufficiency mechanism of ARVC. By ten months they show
    increased right-ventricular volume, reduced right-ventricular function and
    spontaneous ventricular ectopy with preserved left-ventricular size and
    function, and isolated perfused hearts show ventricular tachycardia of
    right-ventricular origin with prolonged right-ventricular conduction times.
    The model is the principal in vivo demonstration that endurance training
    accelerates the ARVC phenotype on a desmosomal-deficiency background, which
    is why it anchors the exercise exposure edge in this entry. Important scope
    limit: histology and electron microscopy did not identify right-ventricular
    abnormalities in affected animals, so the model recapitulates the
    functional, conduction and arrhythmic arms of the disease but NOT the
    fibrofatty replacement that defines its histopathology - it must not be
    cited as evidence for accelerated fibrofatty remodelling.
  experimental_model_type: OTHER
  organism:
    preferred_term: house mouse
    term:
      id: NCBITaxon:10090
      label: Mus musculus
  cell_types:
  - preferred_term: Cardiomyocyte
    term:
      id: CL:0000746
      label: cardiac muscle cell
  modeled_mechanisms:
  - target: Intercalated-disc adhesion failure
    description: >-
      Plakoglobin haploinsufficiency reproduces the desmosomal adhesion defect
      in vivo, and endurance training accelerates its functional and arrhythmic
      consequences - the model system behind the exercise EXACERBATES edge on
      this node.
    evidence:
    - reference: PMID:17030684
      reference_title: >-
        Age- and training-dependent development of arrhythmogenic right
        ventricular cardiomyopathy in heterozygous plakoglobin-deficient mice.
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        Heterozygous plakoglobin deficiency provokes ARVC. Manifestation of the
        phenotype is accelerated by endurance training.
      explanation: >-
        States both halves of what this model contributes: desmosomal
        haploinsufficiency is sufficient to provoke the phenotype, and exercise
        accelerates its manifestation.
  evidence:
  - reference: PMID:17030684
    reference_title: >-
      Age- and training-dependent development of arrhythmogenic right
      ventricular cardiomyopathy in heterozygous plakoglobin-deficient mice.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Ten-month-old heterozygous plakoglobin-deficient mice (plakoglobin+/-)
      had increased right ventricular volume, reduced right ventricular
      function, and spontaneous ventricular ectopy (all P<0.05). Left
      ventricular size and function were not altered.
    explanation: >-
      Documents the model's defining right-ventricular-selective phenotype,
      which is what makes it a model of ARVC specifically rather than of
      generalised cardiomyopathy.
  publication: PMID:17030684
diagnosis:
- name: Task Force Criteria assessment
  diagnosis_term:
    preferred_term: clinical assessment
    term:
      id: NCIT:C124351
      label: Clinical Evaluation
  description: >-
    Diagnosis is based on international Task Force Criteria integrating
    imaging, ECG, arrhythmia, tissue, and family-history findings.
  results: Fulfilment of Task Force Criteria supports the diagnosis of ARVC.
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Clinical diagnosis is made according to international consensus-based
      Task Force Criteria
    explanation: >-
      This directly supports Task Force Criteria-based clinical diagnosis.
- name: Cardiac magnetic resonance imaging
  diagnosis_term:
    preferred_term: magnetic resonance imaging procedure
    term:
      id: NCIT:C16809
      label: Magnetic Resonance Imaging
  description: >-
    Cardiac MRI is used to evaluate right ventricular structure, function, and
    tissue abnormalities.
  results: Structural right ventricular abnormalities support the diagnosis.
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Specific evaluations are recommended in all patients suspected of AC:
      detailed history and family history, physical examination, 12-lead ECG
      (while off medications), signal averaged ECG, 24-hour Holter monitoring,
      maximal exercise testing, two-dimensional echocardiography with
      quantitative wall motion analysis, and more detailed imaging by cardiac
      magnetic resonance imaging (MRI) with delayed enhancement analysis.
    explanation: >-
      This directly supports cardiac MRI as part of the standard diagnostic
      workup.
- name: Genetic testing
  diagnosis_term:
    preferred_term: genetic testing
    term:
      id: NCIT:C15709
      label: Genetic Testing
  description: >-
    Genetic testing helps confirm a familial substrate and identify at-risk
    relatives.
  results: Identification of a pathogenic ARVC-associated variant supports the diagnosis.
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The TFC include six different categories: 1) global and/or regional
      dysfunction and structural RV alterations, 2) tissue characterisation, 3)
      depolarisation abnormalities, 4) repolarisation abnormalities, 5)
      arrhythmias, and 6) family history and genetics.
    explanation: >-
      This directly supports genetics as part of formal ARVC diagnostic
      assessment.
differential_diagnoses:
- name: Idiopathic right ventricular outflow tract ventricular tachycardia
  description: >-
    Idiopathic RVOT ventricular tachycardia can mimic ARVC arrhythmias but
    lacks the familial structural cardiomyopathy substrate.
  notes: >-
    This differential is clinical and important even though a specific MONDO
    disease term is not used here.
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In particular, differentiation from idiopathic VT originating from the RV
      outflow tract (RVOT) can be challenging.
    explanation: >-
      This directly supports idiopathic RVOT VT as an important differential
      diagnosis.
- name: Cardiac sarcoidosis
  disease_term:
    preferred_term: cardiac sarcoidosis
    term:
      id: MONDO:0001707
      label: cardiac sarcoidosis
  description: >-
    Cardiac sarcoidosis can mimic ARVC clinically, on imaging, and even on some
    molecular markers.
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Another disease mimicking AC is cardiac sarcoidosis
    explanation: >-
      This directly supports cardiac sarcoidosis as a key differential.
- name: Myocarditis
  disease_term:
    preferred_term: myocarditis
    term:
      id: MONDO:0004496
      label: myocarditis
  description: >-
    Myocarditis can mimic ARVC clinically and histologically; endomyocardial
    biopsy may be required to distinguish the disorders.
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Myocarditis might also be considered in the differential diagnosis. In
      general, endomyocardial biopsy is required to distinguish myocarditis
      from AC.
    explanation: >-
      This directly identifies myocarditis as a differential and describes the
      role of biopsy in distinguishing it from ARVC.
- name: Brugada syndrome
  disease_term:
    preferred_term: Brugada syndrome
    term:
      id: MONDO:0015263
      label: Brugada syndrome
  description: >-
    Brugada syndrome can overlap through right-precordial ECG abnormalities or
    right-ventricular arrhythmias but lacks the defining fibrofatty
    cardiomyopathy substrate.
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Brugada syndrome with similar electrocardiographic or RV arrhythmias
    explanation: >-
      The review explicitly identifies Brugada syndrome as a rare differential
      because of overlapping ECG or right-ventricular arrhythmias.
- name: Dilated cardiomyopathy
  disease_term:
    preferred_term: dilated cardiomyopathy
    term:
      id: MONDO:0005021
      label: dilated cardiomyopathy
  description: >-
    Advanced ARVC can mimic dilated cardiomyopathy, but arrhythmia-first
    presentation should prompt ARVC consideration.
  evidence:
  - reference: PMID:24817548
    reference_title: >-
      Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk
      management.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: AC may also mimic dilated cardiomyopathy (DCM), especially in the more advanced stages of disease.
    explanation: >-
      This directly supports dilated cardiomyopathy as a differential diagnosis.
discussions:
- discussion_id: gap_arvc_anti_dsg2_autoimmune_causality
  prompt: >-
    Are anti-DSG2 or broader anti-intercalated-disc antibodies antecedent
    drivers, injury-dependent amplifiers, or non-pathogenic markers of
    desmosomal cardiomyocyte damage, and is DAMP-mediated innate activation an
    upstream cause of adaptive autoimmunity or a parallel injury-response
    branch?
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier
  - pathophysiology#Intercalated-disc adhesion failure
  - pathophysiology#Gap-junction and sodium-channel remodeling
  - pathophysiology#Cardiomyocyte apoptosis and loss
  - pathophysiology#Fibrofatty myocardial replacement
  rationale: >-
    Cross-sectional serology and small functional studies leave several
    mutually exclusive interpretations open. The 2018 report found anti-DSG2
    in 12 of 12 and 25 of 25 definite ARVC cases and related antibody density
    to premature ventricular contractions, but its controls did not include
    myocarditis and functional testing used purified total IgG from only two
    patients. Two independent 2026 Boxer cohorts then found anti-DSG2 to be
    nearly ubiquitous or non-discriminatory between affected and screened
    controls, while troponin and NT-proBNP outperformed the antibody in one
    study. These findings refute the original model-specific diagnostic anchor
    without deciding whether a pathogenic human subset exists. A later
    15-patient study found catalytic activity against DSG2 and N-cadherin and
    reduced cohesion in murine culture systems, yet its ELISAs did not detect
    anti-DSG2 binding, only six IgG fractions reduced cellular cohesion, and no
    antigen-specific depletion and add-back or in-vivo transfer established
    that a DSG2-reactive clone was responsible. Family data associate broader
    anti-heart and anti-intercalated-disc antibodies with severity but cannot
    establish whether they precede disease.
    A 2026 follow-up found higher anti-DSG2 levels in 101 definite ARVC cases
    than in selected Ebstein-anomaly, Eisenmenger-syndrome, and healthy controls,
    but the diagnostic cutoff was derived in that same single-centre cohort.
    Its separate higher prognostic threshold tracked cardiac death or
    transplantation rather than arrhythmic events, and no longitudinal samples
    or myocarditis/DCM comparators were included. This is compatible with,
    rather than a refutation of, the 2024 multicenter primary study
    (PMID:39597880), which found 56% anti-DSG2 positivity among 77 ARVC cases
    and 48% among 91 myocarditis or DCM cases, with no titer difference between
    those disease groups and no ARVC clinical correlate for anti-DSG2
    positivity. Persistent anti-DSG2 signals after COVID-19 further show that
    the response is not confined to ARVC. A newer functional study found
    cohesion loss for total IgG from only three of six broader ACM donors;
    GSK-3β inhibition rescued the responder phenotype but did not identify
    DSG2-specific activity or establish a treatment target. Separately,
    cytosolic-DNA–cGAS epistasis in a Dsp-deletion mouse, TLR hypersensitivity
    in human DSP engineered heart tissue, and IL-1β neutralization in a
    Dsg2-mutant mouse support causal or sensitizing innate branches. None
    measured antibody generation or antibody-dependent injury, and their DSP,
    broader ACM, or homozygous-mouse scope cannot be generalized to a human
    ARVC DAMP-to-autoantibody sequence. Resolving temporal order, antigen
    specificity, target accessibility, and necessity or sufficiency is
    therefore required before adding a causal immune edge, clinical biomarker,
    immunosuppressive treatment, or a single DAMP-to-autoantibody cascade.
  evidence:
  - reference: PMID:40608429
    reference_title: >-
      Cardiomyocyte cytosolic nuclear self-DNA contributes to the pathogenesis
      of desmoplakin cardiomyopathy.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Deletion of the Mb21d1 gene encoding CGAS in the Myh6-McmTam Dspfl/fl mice
      prolonged survival, improved cardiac function, attenuated fibrosis, and
      reduced cell death.
    explanation: >-
      Genetic epistasis supports a causal cytosolic-DNA–cGAS contribution in a
      severe homozygous cardiomyocyte-Dsp deletion mouse, but systemic rather
      than cardiomyocyte-specific Mb21d1 deletion limits cell-of-origin
      inference and did not reduce arrhythmia or conduction defects. This is
      not human ARVC evidence, and the study did not test anti-DSG2 production
      or antibody-dependent injury.
  - reference: PMID:38768074
    reference_title: >-
      Susceptibility to innate immune activation in genetically mediated
      myocarditis.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      DSPtv EHTs displayed heightened sensitivity to TLR stimulation, and when
      subjected to strain, DSPtv EHTs developed functional deficits, indicating
      reduced contractile reserve compared with healthy controls.
    explanation: >-
      Patient-derived engineered heart tissues with heterozygous DSP truncating
      variants support genotype-dependent susceptibility to innate stimulation.
      The study models DSP-associated myocarditis rather than exact ARVC, does
      not establish which endogenous DAMP, if any, initiates human ARVC, and
      contains no anti-DSG2 measurement or antibody perturbation. It therefore
      supports a parallel innate branch rather than a serial autoimmune cascade.
  - reference: PMID:42090754
    reference_title: >-
      Interleukin-1β Drives Disease Progression in Arrhythmogenic
      Cardiomyopathy.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      we treated Dsg2mut/mut mice with an anti-IL1B neutralizing antibody and
      observed attenuated fibrosis, reduced levels of inflammatory cytokines
      and chemokines, preserved cardiac function, and diminished conduction
      slowing and automaticity
    explanation: >-
      The intervention portion of this mixed human-and-mouse study gives causal
      support to an IL-1β inflammatory branch in homozygous Dsg2-mutant mice.
      It did not measure or remove anti-DSG2 antibodies, establish a DAMP
      source, or test human treatment, so the result cannot be used to infer a
      DAMP-to-antibody chain or an immune-directed ARVC therapy.
  proposed_experiments:
  - experiment_id: exp_arvc_longitudinal_antibody_origin_and_function
    name: >-
      Genotype-stratified longitudinal autoantibody origin and function study
    description: >-
      Prospectively follow genotype-positive and gene-elusive ARVC participants,
      including unaffected variant-positive relatives, through quiescent,
      myocarditis-like hot-phase, and recovery intervals. Sample clinically
      matched inflammatory and structural cardiac controls on the same schedule,
      use orthogonal blinded antibody assays, and connect within-person antibody
      trajectories to injury, imaging, rhythm, and ex-vivo IgG function.
    experiment_type:
      preferred_term: prospective longitudinal mechanistic cohort study
    model_systems:
    - name: Genotype-stratified ARVC natural-history cohort
      description: >-
        Enroll DSP-, PKP2-, DSG2-, and other genotype-positive ARVC
        participants, gene-elusive cases, and phenotype-negative variant
        carriers. Include both sexes, pediatric and adult strata, and
        prespecified exercise and infection exposures without pooling distinct
        genotypes as though they share one inflammatory trajectory.
      organism:
        preferred_term: human
        term:
          id: NCBITaxon:9606
          label: Homo sapiens
    - name: Clinically relevant cardiac comparator cohort
      description: >-
        Match acute myocarditis, dilated cardiomyopathy, cardiac sarcoidosis,
        right-ventricular pressure or volume overload, post-infection cardiac
        injury, and healthy controls by age, sex, sampling phase, and injury
        burden where feasible.
      organism:
        preferred_term: human
        term:
          id: NCBITaxon:9606
          label: Homo sapiens
    perturbations:
    - name: Within-person injury and recovery time course
      target: mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier
      description: >-
        Obtain scheduled baseline specimens plus event-triggered samples before
        treatment where possible, during peak troponin or imaging activity, and
        through recovery. Record infection, exercise, immunomodulation, heart
        failure therapy, and arrhythmia procedures as time-varying exposures.
    - name: Antigen-specific IgG depletion and add-back
      target: mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier
      description: >-
        Purify total IgG from serial samples, affinity-deplete DSG2-reactive
        fractions with independently verified native extracellular DSG2, and
        add the eluted fraction back at its measured concentration. Compare
        intact IgG with matched Fab and Fc fragments and heat-inactivated or
        complement-reconstituted conditions.
    readouts:
    - name: Orthogonal antibody identity and trajectory
      target: mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier
      description: >-
        Compare preregistered ELISA, immunofluorescence, native-cell binding,
        immunoprecipitation, and cleavage assays. Map epitope, isotype,
        affinity, glycosylation, clonotype, and cross-reactivity to N-cadherin
        and other intercalated-disc antigens at every longitudinal phase.
      assays:
      - preferred_term: orthogonal autoantibody profiling
      - preferred_term: B-cell receptor repertoire sequencing
      direction: THRESHOLD_DEPENDENT
    - name: Necrotic injury and innate immune chronology
      target: discussions#gap_arvc_anti_dsg2_autoimmune_causality
      description: >-
        Quantify troponin, cell-free cardiac DNA, HMGB1 and other candidate
        DAMPs, cytokines, complement products, cardiac magnetic resonance
        edema and scar, positron-emission tomography inflammation, ventricular
        function, and biopsy findings when clinically obtained. Where tissue
        permits, distinguish necrotic injury from apoptosis rather than mapping
        all cardiomyocyte loss to the existing apoptosis-only node.
      assays:
      - preferred_term: serial cardiac magnetic resonance imaging
      - preferred_term: plasma injury and immune mediator profiling
      direction: THRESHOLD_DEPENDENT
    - name: Electrical and adhesion effect of serial IgG
      target: pathophysiology#Gap-junction and sodium-channel remodeling
      description: >-
        At participant-matched concentrations, test intact, depleted, and
        add-back IgG in mechanically loaded human cardiomyocyte cultures for
        DSG2 accessibility and cleavage, cell-cell adhesion, Cx43 localization,
        conduction velocity, gap-junction transfer, cell death, complement
        deposition, and immune-cell recruitment.
      assays:
      - preferred_term: cardiomyocyte adhesion and conduction assay
      - preferred_term: antigen-specific immunoadsorption and add-back assay
      direction: NEGATIVE
    controls:
    - name: Assay and temporal-bias controls
      description: >-
        Lock cutoffs before outcome analysis, blind laboratories to diagnosis
        and phase, include bridge samples and calibrators across sites, verify
        native antigen folding and Fc-tag artifacts, and repeat decisive
        results with a second antigen preparation and laboratory.
    - name: Disease and injury-burden controls
      description: >-
        Analyze each comparator separately and match or adjust for troponin,
        scar, ventricular function, renal function, infection timing, exercise,
        genotype, age, sex, and immunomodulatory exposure. Do not derive a
        diagnostic cutoff and test it in the same cohort.
    decision_criterion: >-
      An antecedent pathogenic contribution requires a reproducible antibody
      clone or activity to be present or rise before objective injury within
      individuals, predict subsequent injury beyond genotype and prior disease
      burden, bind native cardiomyocyte DSG2, and produce an effect lost by
      antigen-specific depletion and restored by concentration-matched add-back.
      An amplifier is supported when the activity appears after structural
      injury but specifically worsens adhesion, conduction, or immune injury.
      A marker is favored when titers follow troponin, DAMP, or scar burden but
      depletion and add-back do not alter function. Similar phase- and
      injury-matched trajectories in myocarditis, sarcoidosis, post-infection
      injury, or right-ventricular overload support an injury-nonspecific
      response; failure of orthogonal assays supports assay artifact. Either
      biomarker-only result is the null outcome and refutes the causal
      driver-or-amplifier hypothesis. This study can establish temporal and
      ex-vivo support but is not alone sufficient for clinical biomarker
      adoption or therapeutic targeting.
    would_support:
    - mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier
    would_refute:
    - mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier
  - experiment_id: exp_arvc_anti_dsg2_causal_epistasis
    name: Antigen-specific anti-DSG2 causal epistasis under mechanical stress
    description: >-
      Reconstruct patient antibody activity in isogenic human cardiac
      microtissues and genotype-specific animal models. Separate antigen
      binding or catalytic effects from Fc-receptor, complement, cellular
      cytotoxicity, and DAMP-sensing pathways using adsorption and add-back,
      monoclonal reconstruction, rescue, and branch-specific epistasis.
    experiment_type:
      preferred_term: antigen-specific cardiac autoantibody causal epistasis study
    model_systems:
    - name: Isogenic human mechanically loaded cardiac immune microtissue
      description: >-
        Combine ventricular iPSC-derived cardiomyocytes with cardiac
        fibroblasts, endothelial cells, macrophages, and natural killer cells in
        an electrically paced, mechanically loaded format. Use multiple donor
        backgrounds and matched wild-type, DSP-, PKP2-, and DSG2-variant lines.
      organism:
        preferred_term: human
        term:
          id: NCBITaxon:9606
          label: Homo sapiens
    - name: Genotype-specific arrhythmogenic cardiomyopathy models
      description: >-
        Use sex-balanced, age-matched Dsp-, Pkp2-, and Dsg2-perturbed mice with
        longitudinal telemetry and imaging. Include wild-type recipients and
        prespecified low- and high-mechanical-load conditions while separating
        developmental from adult-onset injury. Before antibody transfer,
        demonstrate binding to native murine Dsg2 and the intended epitope. For
        Fc- or complement-dependent questions, use variable regions reformatted
        onto a species-compatible murine Fc with murine complement, or validated
        human DSG2/Fc-gamma-receptor/complement-humanized recipients.
      organism:
        preferred_term: house mouse
        term:
          id: NCBITaxon:10090
          label: Mus musculus
    perturbations:
    - name: Patient anti-DSG2 loss-and-add-back series
      target: mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier
      description: >-
        Compare total patient IgG, DSG2-depleted IgG, the affinity-eluted
        add-back fraction, nonbinding IgG, matched Fab and Fc fragments, and
        sequence-defined monoclonal antibodies reconstructed from expanded
        DSG2-reactive B-cell clonotypes. Confirm binding to intact
        cardiomyocyte DSG2 and exclude N-cadherin or unrelated protease
        activity. In mice, interpret only reagents with verified native Dsg2
        cross-reactivity and species-compatible effector handling, or use the
        validated humanized recipients.
    - name: Antigen and effector-pathway epistasis
      target: pathophysiology#Intercalated-disc adhesion failure
      description: >-
        Alter the mapped DSG2 epitope without disrupting baseline adhesion,
        then independently block Fc-gamma receptors, complement, natural-killer
        cell cytotoxicity, candidate catalytic activity, GSK-3β, and p38
        signaling. Rescue with an antibody-insensitive but adhesion-competent
        DSG2 allele. Treat rescue at a shared downstream signaling node as
        mechanistically non-specific unless antigen-specific loss and add-back
        also identify the initiating antibody activity.
    - name: Parallel DAMP-sensing branch perturbation
      target: discussions#gap_arvc_anti_dsg2_autoimmune_causality
      description: >-
        Manipulate HMGB1 or nucleic-acid release and cGAS-STING, selected TLR,
        NLRP3, or IL-1β signaling independently of antibody exposure. Cross
        these perturbations with antigen-specific antibody loss and add-back so
        a parallel innate branch is distinguishable from a required
        DAMP-to-antibody sequence. Quantify necrotic and apoptotic cell death
        separately rather than presuming that DAMP release reports apoptosis.
    readouts:
    - name: Junctional target engagement and function
      target: pathophysiology#Intercalated-disc adhesion failure
      description: >-
        Quantify native DSG2 occupancy or cleavage, desmosomal ultrastructure,
        intercellular force, Cx43 and Nav1.5 localization, dye coupling,
        conduction velocity, triggered activity, and mechanical-load-dependent
        cell loss with blinded longitudinal analysis.
      assays:
      - preferred_term: super-resolution junctional imaging
      - preferred_term: force spectroscopy and multielectrode mapping
      direction: NEGATIVE
    - name: Immune injury and remodeling
      target: pathophysiology#Fibrofatty myocardial replacement
      description: >-
        Resolve complement deposition, Fc-receptor activation, cytotoxicity,
        macrophage states, cytokines, DAMPs, fibrosis, adipose replacement,
        ventricular function, and arrhythmia from acute exposure through
        remodeling.
      assays:
      - preferred_term: spatial single-cell immune profiling
      - preferred_term: telemetry, imaging, and quantitative histopathology
      direction: THRESHOLD_DEPENDENT
    controls:
    - name: Antigen and immunoglobulin specificity controls
      description: >-
        Use participant-matched control IgG, myocarditis and post-infection IgG,
        irrelevant antigen adsorption, sham elution, isotype-matched monoclonal
        controls, endotoxin testing, complement-free and reconstituted media,
        and blinded replication with independently prepared antibody.
    - name: Model and branch controls
      description: >-
        Include no-load and matched-load conditions, genotype-matched untreated
        controls, wild-type recipients, Fc-receptor and complement single
        perturbations, DAMP-pathway perturbations without antibody, and
        antibody exposure without immune cells. Measure antibody
        pharmacokinetics and myocardial access rather than assuming surface
        epitope availability.
    - name: Cross-species antigen and effector compatibility controls
      description: >-
        Before interpreting an in-vivo transfer, verify binding and antigen
        occupancy for the native DSG2 ortholog expressed in that recipient,
        plus Fc-gamma-receptor engagement and complement activation for the
        exact antibody format. Where recipients express murine Dsg2, demonstrate
        cross-reactivity directly; otherwise validate that the humanized target
        and effector components are functional. Treat an incompatible format as
        a failed model-transfer control, not as evidence against causality.
    decision_criterion: >-
      A direct autoantibody driver requires a sequence-defined anti-DSG2
      antibody or affinity-purified fraction to reproduce junctional,
      electrical, and tissue injury by itself; loss of effect after
      DSG2-specific adsorption or epitope alteration; restoration by add-back;
      and the predicted antigen or effector-pathway rescue in both human tissue
      and an independent in-vivo model. The in-vivo arm counts toward this
      criterion only after antigen and Fc/complement compatibility are verified;
      otherwise effector inference is bounded to the human microtissue and a
      negative mouse result is non-informative. Activity only after
      pre-existing desmosomal injury or mechanical stress, with a reproducible
      increase in injury magnitude, supports an amplifier. Association without
      antigen-specific functional effects is the biomarker-only null and
      refutes this causal hypothesis. Persistence after DSG2 adsorption or
      epitope rescue, equal effects from control or inflammatory-disease IgG,
      failure to reach myocardium, or dependence on nonspecific protease
      contamination also refutes an anti-DSG2-specific mechanism. Independent
      DAMP effects after antibody removal establish a parallel innate branch;
      DAMP perturbation must alter antibody generation and antibody-dependent
      injury in order to support a serial cascade.
    would_support:
    - mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier
    would_refute:
    - mechanistic_hypotheses#anti_dsg2_causal_injury_driver_or_amplifier
clinical_trials: []
datasets:
- accession: geo:GSE164490
  title: Pericardial fluid microRNAs in patients with arrhythmogenic right ventricular cardiomyopathy or ischemic heart disease
  description: Pericardial fluid is enriched by biologically active molecules of cardiovascular origin including microRNAs. Investigation of the disease-specific extracellular microRNAs could shed light on the molecular processes underlying disease development. Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart disease characterized by life-threatening arrhythmias and progressive heart failure development. The current data about the association between microRNAs and ARVC development are limited.
  organism:
    preferred_term: human
    term:
      id: NCBITaxon:9606
      label: Homo sapiens
  data_type: BULK_RNA_SEQ
  sample_count: 9
  publication: PMID:33816578
  notes: Identified by GEO DataSets index search for arrhythmogenic right ventricular cardiomyopathy (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
- accession: geo:GSE29819
  title: Myocardial transcriptome analysis of human arrhythmogenic right ventricular cardiomyopathy (ARVC)
  description: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy primarily of the right ventricle characterized through fibrofatty replacement of cardiomyocytes. The genetic etiology in ARVC patients is most commonly caused by dominant inheritance and high genetic heterogeneity. Though histological examinations of ARVC affected human myocardium reveals fibrolipomatous replacement, the molecular mechanisms leading to loss of cardiomyocytes are largely unknown.
  organism:
    preferred_term: human
    term:
      id: NCBITaxon:9606
      label: Homo sapiens
  data_type: MICROARRAY
  sample_count: 38
  publication: PMID:22085907
  notes: Identified by GEO DataSets index search for arrhythmogenic right ventricular cardiomyopathy (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
- accession: geo:GSE253226
  title: PKP2 Gene Therapy Improves Heart Function and Reduces Mortality in a Pkp2-deficient Mouse Model of Arrhythmogenic Right Ventricular Cardiomyopathy
  data_type: BULK_RNA_SEQ
  sample_count: 112
  publication: PMID:38499690
  notes: Identified by GEO DataSets index search for arrhythmogenic right ventricular cardiomyopathy (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
notes: >-
  Asta deep research was completed for this disorder. Final curation
  prioritized disease-root mechanisms and management supported by disorder-
  specific ARVC reviews already present in the local cache.

📚

References & Deep Research

References

1

PMID:20301310

Arrhythmogenic Right Ventricular Cardiomyopathy Overview.

No top-level findings curated for this source.

Deep Research

3

Asta ▸

Asta Literature Retrieval: Pathophysiology and clinical mechanisms of arrhythmogenic right ventricular cardiomyopathy. Core disease mechanisms,...

Asta Scientific Corpus Retrieval 20 citations 2026-04-14T16:27:15.581565

Asta Literature Retrieval: Pathophysiology and clinical mechanisms of arrhythmogenic right ventricular cardiomyopathy. Core disease mechanisms,...

This report is retrieval-only and is generated directly from Asta results.

Papers retrieved: 20
Snippets retrieved: 20

Relevant Papers

[1] Special issue Heidelberg Heart II: Abstracts of oral and poster presentations

Authors: W. Franke
Year: 2012
Venue: Cell and Tissue Research
URL: https://www.semanticscholar.org/paper/969e98278c5ef7588af320ca0f980b09522c21e7
DOI: 10.1007/s00441-012-1412-x
PMCID: 3349853
Citations: 1
Summary: Interference with the architectural roles of desmosome molecules has been assumed to make an important contribution to tissue responses that lead to disease pathogenesis, functions that transcend their well-established roles in adhesion and IF-anchorage are emerging.
Evidence snippets:
Snippet 1 (score: 0.691) > A 16 -Disease mechanisms in arrhythmogenic cardiomyopathy: immunohistochemistry and beyond Jeffrey E. Saffitz Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA, USA jsaffitz@bidmc.harvard.edu Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a primary myocardial disorder characterized by an especially high incidence of ventricular arrhythmias and sudden death. The identification of desmosomal gene mutations in ∼50 % of patients has led to the idea that ARVC is a disease of abnormal cell-cell adhesion. However, recent insights gained largely from studies of the human disease suggest a greater degree of complexity. These insights include observations that: (1) plakoglobin (γ-catenin) is consistently redistributed from desmosomes to intracellular/nuclear sites in all forms of ARVC regardless of the underlying mutation, (2) ARVC patients have elevated circulating cytokine levels and myocardial production of cytokines, and (3) disease flares often follow strenuous exercise in ARVC patients. Objective: to define the genetic and mechanistic basis of arrhythmogenic cardiomyopathy. Background: arrhythmogenic cardiomyopathy, previously known as arrhythmogenic right ventricular dysplasia (ARVD) or arrhythmogenic right ventricular cardiomyopathy (ARVC), is characterized by myocardial fibrofatty replacement, ventricular dysfunction, and arrhythmias associated with sudden death. Autosomal dominant inheritance is most common, and reduced penetrance is the rule of thumb, but the underlying basis of low penetrance is poorly understood. The causative genes identified to date are generally associated with desmosome function, the "final common pathway" of this disease. We previously described compound and digenic heterozygosity as a feature of this disorder which plays a role in the development of the clinical phenotype and the severity of disease.

[2] Prediction of Ventricular Arrhythmias in Patients at Risk of Sudden Cardiac Death

Authors: K. Haugaa, J. Amlie, T. Edvardsen
Year: 2011
Venue: Unknown venue
URL: https://www.semanticscholar.org/paper/366318c37e6eff3d2740558b56fc30d650950fd1
DOI: 10.5772/20670
Summary: In this report, a novel echocardiographic method will be presented in order to evaluate the cardiac contractility pattern in patients at increased risk of life-threatening arrhythmias.
Evidence snippets:
Snippet 1 (score: 0.652) > Arrhythmogenic right ventricular cardiomyopathy is an inheritable, chronic and progressive cardiomyopathy and is one of the leading causes of sudden unexpected cardiac death in previously healthy young individuals (Sen-Chowdhry, 2010a; Thiene, 1988). Prevalence has been estimated to be at least 1 in 1000 (Sen-Chowdhry, 2010a). Recent molecular genetic reports have revealed arrhythmogenic right ventricular cardiomyopathy as mainly a desmosomal disease (Xu, 2010). Mutations in one of the 5 desmosomal or 3 extra desmosomal genes so far identified, lead to progressive loss of myocytes, followed by fibro-fatty replacement. Penetrance is age and gender dependent and the progressive clinical picture is highly variable (Dalal, 2006). Four clinical stages have been documented: An early concealed phase, overt electrical disorder, isolated right heart failure (Fig 4a), and biventricular pump failure (Fig 4b) (Basso, 1996;Sen-Chowdhry, 2007;Sen-Chowdhry, 2010a). Importantly, life-threatening arrhythmias can occur with only discrete or even absent myocardial structural changes (Senwww.intechopen.com Chowdhry, 2010b). Risk stratification of ventricular arrhythmias and sudden cardiac death is therefore challenging. Mechanisms of arrhythmias in early stages of arrhythmogenic right ventricular cardiomyopathy are probably due to dysfunction of desmosomal proteins and disturbed cell to cell coupling (Saffitz, 2009). In later stages of arrhythmogenic right ventricular cardiomyopathy when structural abnormalities in the myocardium have developed, reentrant ventricular arrhythmias can occur in tissue with fibro fatty replacement. Therefore, electrical conduction delay with consequent electrical dispersion has been suggested as an important mechanism of ventricular arrhythmias (Amlie, 1997;Turrini, 2001). In a recent study we investigated if arrhythmogenic right ventricular cardiomyopathy patients had cardiac contraction heterogeneity assessed as mechanical dispersion and

[3] Update on Genes Associated with Arrhythmogenic Cardiomyopathy

Authors: M. Vallverdú-Prats, M. Alcalde, G. Sarquella-Brugada, S. César, E. Arbelo et al.
Year: 2020
Venue: Cardiomyopathy - Disease of the Heart Muscle [Working Title]
URL: https://www.semanticscholar.org/paper/1ffe68704d6dcbf0977f3587844705d96df69259
DOI: 10.5772/INTECHOPEN.95332
Citations: 1
Summary: Recent advances in the knowledge regarding the genetic basis of arrhythmogenic cardiomyopathy are focused on, suggesting the existence of unknown genes as well as other genome alterations not yet discovered.
Evidence snippets:
Snippet 1 (score: 0.623) > Arrhythmogenic cardiomyopathy is an inherited rare cardiac disease characterized by progressive replacement of myocardium by fibrofatty tissue, leading to ventricular arrhythmias and sudden cardiac death. Structural abnormalities mainly occur in the right ventricle, but it is well recognized that also sole left ventricular involvement and even biventricular substitution is common, particularly in advanced stages of the disease. Several molecular mechanisms are involved in the phenotype of ACM such as myocardial inflammation and signaling pathways that cause fibrosis and adipogenesis. Today, most of these mechanisms are not completely understood. Task Force Criteria for the diagnosis of arrhythmogenic cardiomyopathy include several clinical tests and also genetic data. Despite progressive improvement in diagnosis, it is difficult to obtain conclusive risk stratification in families suffering from arrhythmogenic cardiomyopathy. Hundreds of rare alterations are reported in mainly genes encoding desmosomal proteins, but there are also other causal genes with several functions within the cardiac tissue. A comprehensive genetic analysis may identify the potential genetic cause of the disease in nearly 60% of cases. Genetic testing is especially useful in families with at least one affected member that carries a potential deleterious alteration because it allows early identification and adoption of therapeutic measures among relatives at risk of malignant arrhythmias. Currently, one of main challenges is the genetic interpretation and clinical translation of amount of genetic data generated by new genetic technologies. > Update on Genes Associated with Arrhythmogenic Cardiomyopathy DOI: http://dx.doi.org/10.5772/intechopen.95332

[4] Focus on arrhythmogenic right ventricular cardiomyopathy

Authors: G. Sinagra, C. Cappelletto, A. de Luca, S. Romani, A. Paldino et al.
Year: 2020
Venue: European Heart Journal Supplements : Journal of the European Society of Cardiology
URL: https://www.semanticscholar.org/paper/e4392c990ad29851d1c76e19a03845d6db0c611a
DOI: 10.1093/eurheartj/suaa152
PMID: 33239987
PMCID: 7673615
Citations: 7
Summary: The main goal in the management of patients is the prevention of sudden cardiac death, where implantable cardioverter-defibrillator is the only effective therapeutic strategy.
Evidence snippets:
Snippet 1 (score: 0.615) > Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is a primary heart muscle disease, characterized by progressive epi-endocardial replacement of cardiomyocytes with fibro-adipose tissue. Clinically, ARVC is characterized by ventricular arrhythmias, heart failure (HF), and sudden cardiac death (SCD). 1 The first descriptions of the disease were reported in the '70 s of the last century but only in 1995 ARVC become part of the WHO/IFSC (World Health Organization/International Society and Federation of Cardiology) Classification of Cardiomyopathies. > Originally the disease was known as 'Arrhythmogenic Dysplasia of the Right Ventricle' and was considered as a developmental defect of the right ventricle (RV) myocardium. > Since then, significant progress has been made in knowledge of pathogenetic mechanisms, natural history and clinical management of the disease. > Arrhythmogenic right ventricular cardiomyopathy is caused by a genetic defects, mainly affecting cell junction proteins (desmosomes). Structural alterations may be absent or mild in the initial stages of the disease, confined to a limited regions of the RV, the so called 'triangle of dysplasia'. With the progression of the disease also the left ventricle (LV) may be involved. > ][3][4][5][6] Growing evidences of genotypic overlap between ARVC and 'arrhythmic' Dilated Cardiomyopathy (caused by mutations of desmosomal genes, filamin or lamin) led to the definition of 'Arrhythmogenic Cardiomyopathy' (AC). 3,5,6 rrhythmogenic cardiomyopathy includes a heterogeneous spectrum of phenotypes, ranging from isolated involvement of the RV to exclusive involvement of the LV, sharing a common genetic basis and clinically characterized by electrical instability, that could lead to atrial or ventricular tachyarrhythmias and bradyarrhythmias.

[5] Arrhythmogenic Cardiomyopathy: Genetic Pathology, Inflammatory Syndrome, or both?

Authors: Héctor O. Rodríguez
Year: 2017
Venue: EMJ Cardiology
URL: https://www.semanticscholar.org/paper/a13b5f1adff7a0f90200a5d30040b7263a5f2f9b
DOI: 10.33590/emjcardiol/10314768
Summary: Findings taken from other sudden death-causing cardiomyopathies allow us to propose proinflammatory cytokines, such as tumour necrosis factor and interleukins 17 and 2, as possible serological markers of sudden death and/or ventricular dysfunction in order to conduct further research and identify diagnosis/prognosis markers for ACM.
Evidence snippets:
Snippet 1 (score: 0.596) > Arrhythmogenic cardiomyopathy (ACM), previously called arrhythmogenic right ventricular cardiomyopathy or arrhythmogenic right ventricular dysplasia, was classically defined as a fibro-fatty substitution of ventricular myocardium. Recent advances have given a more complete view of its pathophysiology, including genetic and electrophysiological criteria to classify the disease. Therefore, we can consider ACM as a ventricular arrhythmogenic syndrome with a structural substrate associated to intercalated disc protein mutations. The possible role of ionic disturbances in lethal arrhythmias make it challenging to specify a precise definition and adopt a rational approach to prevention and therapeutics and this should be acknowledged. > Initially, ACM was reported mainly in the right ventricle, 1 but may also implicate the left ventricle, as well as both ventricles simultaneously. ACM principally affects young men and can cause sudden death by ventricular arrhythmias, 2 especially in athletes, which is not always associated to structural changes in ventricular walls. As a result of these variables, we can classify ACM into ionic and non-ionic-associated origin by the presence or absence of structural ventricular changes. In this review, we explore the possible role of inflammation as a concomitant cause in ACM, a mechanism poorly explored in the literature and one that possibly should be included in further classifications. > ACM was first described early in the 1980s. Initially, it was reported as hypokinetic cardiomyopathy associated with non-ischaemic tachycardia. 1 Progressively, ACM was described as being in association with lethal arrhythmias, 3 functional myocardial involvement, 4 and biventricular affectation. 5,6 0][11][12][13] In the next sections, we briefly describe the most recent advances in the comprehension of the pathophysiology of ACM.

[6] Molecular Mechanisms of Inherited Arrhythmias

Authors: C. Wolf, C. Berul
Year: 2008
Venue: Current Genomics
URL: https://www.semanticscholar.org/paper/8dc574fc997d6e863ac851b4a75d122de6d9aa61
DOI: 10.2174/138920208784340768
PMID: 19440513
PMCID: 2679644
Citations: 26
Influential citations: 3
Summary: The molecular basis of inherited arrhythmias in structurally normal and altered hearts is summarized, which helps explain the molecular and functional mechanisms of long QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, and other electrical myopathies.
Evidence snippets:
Snippet 1 (score: 0.592) > Inherited arrhythmias can be life threatening, and are major cause of mortality and morbidity in developed nations. Identification of molecular pathways that increase susceptibility to arrhythmia is necessary to prevent disease occurrence, to improve current therapies and to target new drug development. In recent years, the discovery of pathogenic mutations in inherited arrhythmia syndromes has provided novel insights for the understanding and treatment of diseases predisposing to sudden cardiac death. In patients with the long QT syndromes (LQTS), genotype-phenotype relation studies [1] and genetic testing have influenced patient risk stratification [2] and refined treatment strategies [3]. > Arrhythmia mechanisms include abnormal automaticity, triggered activity, and re-entrant excitation. Each of these mechanisms can occur in any type of myocardial disease or in inherited cardiac arrhythmias. The current article focuses on molecular mechanisms of arrhythmias in the structurally abnormal and normal heart. Hypertrophic and dilated cardiomyopathies, as well as arrhythmogenic right ventricular dysplasia/cardiomyopathy are common substrates of inherited arrhythmias in the structurally abnormal heart. Genetic diseases causing arrhythmias in the structural normal heart, also called electrical myopathies, include the long QT syndromes, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia (CPVT), and non-defined familiar idiopathic ventricular fibrillation. Most, but not all of these disorders are caused by mutations in genes encoding cardiac ion-channel proteins. Among family members carrying an identical mutation in a single gene, remarkable phenotypic variability and expressivity may be observed, suggesting both environmental [4] and genetic modifiers [5].

[7] Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk management

Authors: J. Groeneweg, J. Groeneweg, J. Heijden, J. Heijden, D. Dooijes et al.
Year: 2014
Venue: Netherlands Heart Journal
URL: https://www.semanticscholar.org/paper/7b6e9177653c6930262a978a3f44f7c979cfcce8
DOI: 10.1007/s12471-014-0563-7
PMID: 24817548
PMCID: 4099433
Citations: 28
Influential citations: 3
Summary: Therapeutic options in symptomatic patients include antiarrhythmic drugs, catheter ablation, and ICD implantation, and patients with AC and also all pathogenic mutation carriers should be advised against practising competitive and endurance sports.
Evidence snippets:
Snippet 1 (score: 0.591) > Arrhythmogenic right ventricular (RV) dysplasia/ cardiomyopathy (ARVD/C) is histopathologically characterised by progressive fibrofatty replacement of cardiomyocytes, primarily in the right ventricle [1][2][3]. However, histopathologically and functionally the left ventricle is affected in many cases and both ventricles are similarly affected by desmosomal and gap junctional protein redistribution [4,5]. Because of these observations, at present arrhythmogenic cardiomyopathy (AC) is the preferred terminology [6]. AC can be defined as a structural myocardial disease preceded by ventricular arrhythmias. Typical ARVD/C with predominant RV abnormalities can be considered a large and important subcategory of AC. Clinical diagnosis is made according to international consensus-based Task Force Criteria [7,8]. > The first series of ARVD/C patients was published in 1982 [1]. It was described as a developmental disease of the RV musculature, hence the terminology 'dysplasia'. In the past 25 years, increased insight into the development of the disease as well as the discovery of pathogenic gene mutations involved led to the current understanding that AC is a genetically determined cardiomyopathy. The molecular genetic substrate for the disease is mainly acknowledged in genes encoding desmosomal adhesion proteins in the intercalated disk [9][10][11][12][13][14]. > This review provides an overview of AC, from phenotypic and genetic features of the disease, to diagnosis, risk stratification and treatment options.

[8] Arrhythmogenic right ventricular cardiomyopathy: diverse substrate characteristics and ablation outcome.

Authors: W. Cheng, F. Chung, Yenn‐Jiang Lin, L. Lo, S. Chang et al.
Year: 2021
Venue: Reviews in cardiovascular medicine
URL: https://www.semanticscholar.org/paper/21563d7592478c853ce2ce3c54165855ba02fabf
DOI: 10.31083/j.rcm2204136
PMID: 34957771
Citations: 7
Summary: A better understanding of the pathogenesis, underlying arrhythmogenic substrates, and putative VT isthmus in ARVC contributes to a significant improvement in ablation outcomes through comprehensive endocardial and epicardial approaches.
Evidence snippets:
Snippet 1 (score: 0.590) > Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy caused by defective desmosomal proteins. The typical histopathological finding of ARVC is characterized by progressive fibrofatty infiltration of the right ventricle due to the dysfunction of cellular adhesion molecules, thus, developing arrhythmogenic substrates responsible for the clinical manifestation of ventricular tachycardia/fibrillation (VT/VF). Current guidelines recommend implantable cardiac defibrillator (ICD) implantation to prevent sudden cardiac death (SCD) in ARVC, especially for those experiencing VT/VF or aborted SCD, while antiarrhythmic drugs, despite their modest effectiveness and several undesirable adverse effects, are frequently used for those experiencing episodes of ICD interventions. Given the advances in mapping and ablation technologies, catheter ablation has been implemented to eliminate drug-refractory VT in ARVC. A better understanding of the pathogenesis, underlying arrhythmogenic substrates, and putative VT isthmus in ARVC contributes to a significant improvement in ablation outcomes through comprehensive endocardial and epicardial approaches. Regardless of ablation strategies, there is a diversity of arrhythmogenic substrates in ARVC, which could partly explain the nonuniform ablation outcome and long-term recurrences and reflect the role of potential factors in the modification of disease progression and triggering of arrhythmic events.

[9] Distinct Myocardial Transcriptomic Profiles of Cardiomyopathies Stratified by the Mutant Genes

Authors: K. Sielemann, Z. Elbeck, A. Gärtner, A. Brodehl, C. Stanasiuk et al.
Year: 2020
Venue: Genes
URL: https://www.semanticscholar.org/paper/9f8ceb185d87f8def9e3c9dc016922d53a936b4a
DOI: 10.3390/genes11121430
PMID: 33260757
PMCID: 7768427
Citations: 10
Summary: Genotype-specific differences in regulated pathways, Gene Ontology (GO) terms as well as gene groups like secreted or regulatory proteins and potential candidate drug targets revealing specific molecular pathomechanisms for the four subtypes of genetic cardiomyopathies are identified.
Evidence snippets:
Snippet 1 (score: 0.589) > TTNtv are associated with incomplete penetrance and late onset heart failure, whereas patients with i.e., pathogenic RBM20 or LMNA mutations are affected by comparably early cardiomyopathies with incomplete penetrance [3]. Arrhythmogenic right ventricular cardiomyopathy (ARVC) is most frequently associated with defects in the desmosome [10]. The right ventricle is mainly affected, but with ongoing disease, the left ventricle is significantly affected as well [12]. Left ventricular forms of arrhythmogenic cardiomyopathy (ACM), which is a broader description of ARVC, are almost missing in the 2010 update diagnostic criteria, which are therefore not entirely specific for the disease [13,14]. However, due to advances in the clinical, pathological and genetic architecture of ARVC [14], left ventricular involvement and left-dominant or biventricular subtypes are now increasingly recognized. Further, genotype-phenotype correlation studies have recently identified clinical forms of ARVC associated with early dominant left ventricular involvement, which may parallel or even exceed the severity of right ventricular involvement [13,15,16]. The introduction of the term ACM was therefore recently proposed by the Heart Rhythm Society/European Heart Rhythm Association (HRS/EHRA) [17] to embrace the different pathologies of the disease [14]. However, there is still a lack of diagnostic and prognostic data and of the genetic basis and pathogenesis of ACM [18]. In our study, we therefore included ACM cases and compared this cardiomyopathy to other forms based on their genotypes. Mutations in the desmosomal genes cause ARVC but other genes like e.g., FLNC [19] can be affected as well [3]. However, the most frequent affected gene is PKP2 (11-51%) [5] encoding the desmosomal plaque protein plakophilin 2. This protein mediates the molecular connection of the desmosomal cadherins with the cytolinker protein desmoplakin.

[10] Blockade of the Adenosine 2A Receptor Mitigates the Cardiomyopathy Induced by Loss of Plakophilin-2 Expression

Authors: M. Cerrone, C. J. V. van Opbergen, K. Malkani, N. Irrera, Mingliang Zhang et al.
Year: 2018
Venue: Frontiers in Physiology
URL: https://www.semanticscholar.org/paper/8535f5196dd6979a590543055872e433646d94c1
DOI: 10.3389/fphys.2018.01750
PMID: 30568602
PMCID: 6290386
Citations: 11
Summary: Paracrine adenosine 2A receptor activation contributes to the progression of fibrosis and impaired cardiac function in animals deficient in PKP2.
Evidence snippets:
Snippet 1 (score: 0.583) > Arrhythmogenic right ventricular cardiomyopathy (ARVC, indicated also as "arrhythmogenic cardiomyopathy, ACM" or "arrhythmogenic right ventricular dysplasia, ARVD") is an inherited disease characterized by fibrofatty infiltration of right ventricular (RV) predominance, ventricular arrhythmias and high propensity for sudden death in the young (Basso et al., 2009). Cardiac arrest is often associated with exercise, and it is the first disease manifestation in a high proportion of probands. (Basso et al., 2009;Groeneweg et al., 2015) Most often the disease begins with a subclinical, concealed stage, followed by overt stages of RV predominance (though LV is often involved) then biventricular dilated cardiomyopathy and failure. (Basso et al., 2009;Groeneweg et al., 2015) The disease can progress to end-stage heart failure and in the absence of a heart transplant, death. At present, no medical treatment exists to prevent or delay the progression of the disease. > Familial ARVC is most commonly consequent to mutations in the gene coding for Plakophilin-2 (PKP2; Groeneweg et al., 2015), a protein classically defined as a component of the desmosome, though also known to participate in other cellular functions. The relation between PKP2 on one hand, and the structural disease that results from its absence or altered sequence, on the other, remains a matter of investigation. Previous studies on the molecular mechanisms leading to fibro-adiposis in ARVC have proposed that activation of the Hippo and Wnt pathways are the causative mechanisms of the structural disease (Garcia-Gras et al., 2006;Chen et al., 2014). Recently, Dubash et al. (2016) demonstrated an additional route whereby loss of PKP2 expression causes an increase in the expression of TGF-beta1, and activation of the p38-MAPK-dependent pro-fibrotic program.

[11] The Challenges of Diagnosis and Treatment of Arrhythmogenic Cardiomyopathy: Are We there yet?

Authors: A. Spadotto, D. Morabito, A. Carecci, G. Massaro, G. Statuto et al.
Year: 2022
Venue: Reviews in Cardiovascular Medicine
URL: https://www.semanticscholar.org/paper/c49b90d8007f1358bc50f48696245a86fda4560b
DOI: 10.31083/j.rcm2308283
PMID: 39076647
PMCID: 11266951
Citations: 6
Summary: Background: we sought to review the evolution in the diagnosis and treatment of Arrhythmogenic Cardiomyopathy (ACM), a clinically multifaceted entity beyond the observation of ventricular arrhythmias, and the outcome of therapies aiming at sudden death prevention in a single center experience. Methods: retrospective analysis of the data of consecutive patients with an implanted cardioverter-defibrillator (ICD) and a confirmed diagnosis of ACM according to the proposed Padua Criteria, who were...
Evidence snippets:
Snippet 1 (score: 0.578) > This review on Arrhythmogenic Cardiomyopathy (ACM) focuses on its diagnostic challenges, on the debated role of risk-stratification of sudden cardiac death, and reports the outcome of ICD treatment for sudden death prevention in all cardiac phenotypes. ACM is a general term that encompasses a group of diseases different amongst themselves depending on type of pathologic involvement of the heart, aetiology, and genetics. While it is rationale to assign a specific nosographic classification to entities having a homogeneous genetic background (mutations of the same gene/group of genes) resulting in a common clinical phenotype (Figs. 1,2), it is much more clinically challenging to classify a disease whose phenotypic appearance is the outcome of several unlinked genetic diseases with different pathogenic mechanisms. Even more difficult is disease classification when different mutations of the same gene are disease-causative in the same organ with differ-ent phenotypes (hypertrophic vs arrhythmogenic disease). Debate as to whether a genomic-based classification of diseases or a clinical phenotype-based one is more appropriate is ongoing. We focus on ACM phenotype expressed as right ventricular, biventricular, and left ventricular involvement of the heart caused by progressive replacement of the myocardium by fibrotic or fibro-fatty tissue, which acts as an arrhythmogenic substrate predisposing to lifethreatening ventricular arrhythmias and heart failure due to systolic ventricular dysfunction, caused by inherited genetic abnormalities. The earliest clinical manifestations of these diseases are ventricular arrhythmias, typically occurring between the third and the fourth decade, though they represent a relevant cause of sudden death in adolescents, especially in the physically active and in high-level athletes [1]. Sudden cardiac death (SCD) can be the first manifestation in a minority of patients, thereby heightening medical attention in the event ventricular arrhythmias are detected in otherwise healthy and young individuals.

[12] Arrhythmogenic Cardiomyopathy PKP2-Related: Clinical and Functional Characterization of a Pathogenic Variant Detected in Two Italian Families

Authors: E. Marchionni, Sonia Lomuscio, A. Latini, M. Murdocca, F. Romeo et al.
Year: 2025
Venue: Genes
URL: https://www.semanticscholar.org/paper/afff57f85745a4204acf47c04f8d5948b7866657
DOI: 10.3390/genes16040419
PMID: 40282378
PMCID: 12027432
Summary: The clinical onset of ACM can be Sudden Cardiac Death, and hence, it is recommended to perform a segregation test on first-degree relatives of pathogenic variant carriers, even if they are asymptomatic, with the purpose of promptly detecting those at risk.
Evidence snippets:
Snippet 1 (score: 0.573) > Arrhythmogenic Cardiomyopathy (ACM, MIM 609040) is a genetic disease characterized by incomplete penetrance and a wide variable expressivity. In most cases, it is caused by pathogenic variants in genes encoding for desmosomal proteins, which are involved in cardiomyocyte adhesion [1]. Among the desmosomal genes, Plakophilin-2 (PKP2, MIM 602861) is the most frequently associated with ACM [2]. Reduced expression of desmosomal proteins has been shown to induce cardiac dysfunction [3]. This is attributable to a progressive weakening of cell-to-cell junctions leading to fibrotic remodeling areas, due to a decrease in mechanical traction tolerance [4]. > The consequential cardiomyocyte apoptosis results in an uneven slowing of signal propagation, which implies the development of arrhythmias in affected patients. This explains why ACM is associated with a high risk of Sudden Cardiac Death (SCD), especially when PKP2 mutation carriers have not undergone appropriate cardiological follow-up [5]. > Clinical diagnosis of ACM is based on evaluating signs and symptoms, imaging, histological characterization, and electrocardiographic features. It is also important to obtain medical information about patients' pedigrees, as approximately 30% to 50% of those affected have a positive family history [6]. > According to the 2010 Revised Task Force Criteria for the Diagnosis of Arrhythmogenic Cardiomyopathy (formerly known as Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia), all the clinical features detected through the cardiological assessment can be sorted into six different categories, each consisting of major and minor criteria: > Morphofunctional Alterations (right ventricular (RV) dilatation or wall motion bnormalities); 2. > Myocardium Histology (fibro-adipose replacement); 3. > Repolarization Abnormalities (inverted T waves in right precordial leads); 4. > Depolarization/Conduction Abnormalities (ε waves in the right precordial leads, prolonged QRS duration); 5.

[13] The genetic background of arrhythmogenic right ventricular cardiomyopathy

Authors: S. Ohno
Year: 2016
Venue: Journal of Arrhythmia
URL: https://www.semanticscholar.org/paper/913fda12a4950f207552feb583a7d267a58e34a5
DOI: 10.1016/j.joa.2016.01.006
PMID: 27761164
PMCID: 5063271
Citations: 76
Influential citations: 8
Summary: The clinical issues of ARVC from the genetic background are discussed and many studies have reported clinical manifestations of, prognosis for, and appropriate therapies for AR VC from the perspective of gene mutations.
Evidence snippets:
Snippet 1 (score: 0.564) > Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by degeneration of the right ventricle and ventricular tachycardia originating from the right ventricle. Additionally, the disease is an inherited cardiomyopathy that mainly follows the autosomal dominant pattern. More than 10 genes have been reported as causative genes for ARVC, and more than half of ARVC patients carry mutations in desmosome related genes. The desmosome is one of the structures involved in cell adhesion and its disruption leads to various diseases, including a skin disease called pemphigus. Among desmosome genes, mutations in PKP2 are most frequently identified in ARVC patients. Although the genotype–phenotype correlations remain to be fully studied, many studies have reported clinical manifestations of, prognosis for, and appropriate therapies for ARVC from the perspective of gene mutations. A collective review of these reports would enhance the understanding of ARVC pathogenesis and clinical manifestation. This review discusses the clinical issues of ARVC from the genetic background.

[14] Using Zebrafish Animal Model to Study the Genetic Underpinning and Mechanism of Arrhythmogenic Cardiomyopathy

Authors: Yujuan Niu, Yuanchao Sun, Yuting Liu, Ke Du, Xiaolei Xu et al.
Year: 2023
Venue: International Journal of Molecular Sciences
URL: https://www.semanticscholar.org/paper/1ea7360cab3224c8bbe08bf376ceb2f4c216ca49
DOI: 10.3390/ijms24044106
PMID: 36835518
PMCID: 9966228
Citations: 5
Summary: Arrhythmogenic cardiomyopathy (ACM) is largely an autosomal dominant genetic disorder manifesting fibrofatty infiltration and ventricular arrhythmia with predominantly right ventricular involvement. ACM is one of the major conditions associated with an increased risk of sudden cardiac death, most notably in young individuals and athletes. ACM has strong genetic determinants, and genetic variants in more than 25 genes have been identified to be associated with ACM, accounting for approximately...
Evidence snippets:
Snippet 1 (score: 0.562) > Arrhythmogenic cardiomyopathy (ACM) is an updated term for the heart muscle disorder originally known as arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C), manifesting as malignant ventricular arrhythmias and fibrofatty infiltration in the myocardium of both ventricles, with right ventricular involvement being more common. Depending on the patient cohorts studied, the prevalence of ACM is estimated to be 1 case per 2000 to 5000 individuals in the general population [1]. While recognized as a rare form of cardiac disease, ACM with sustained ventricular arrhythmia represents a major risk condition, causing a significant proportion of sudden cardiac deaths, especially in young individuals and athletes [2,3]. > In the 2000s, through pedigree linkage analysis, homozygous truncating mutations in the junction plakoglobin (JUP) and desmoplakin (DSP) genes were identified in parallel to cause ACM that overlaps with cardio-cutaneous syndromes, representing the first two genetic studies to recognize ACM as an inheritable type of cardiomyopathy [4,5]. Since then, over the past almost two decades, mostly through the combined approaches of familial genetic linkage and candidate gene sequencing, numerous pathogenic variants in more than 25 genes have been identified to cause ACM, accounting for up to 60% of ACM cases [6][7][8][9]. These findings underscore the strong genetic determinant of ACM. However, the genotype-phenotype relationship in ACM patients remains complex; even for ACM cases harboring the same identified gene mutations, disease onset and disease severity can manifest with highly variable expressivity, likely due to the contributions of other comorbidities combined with different genetic background and environmental factors [10,11]. In addition, for patients with known genetic causes, the molecular mechanisms underlying their ACM disease progression remain poorly understood. Currently, clinical management of ACM patients mainly focuses on the general control of heart failure and the prevention of arrhythmic sudden cardiac death (SCD) [12].

[15] Contemporary genetic testing in inherited cardiac disease: tools, ethical issues, and clinical applications

Authors: F. Girolami, G. Frisso, M. Benelli, L. Crotti, M. Iascone et al.
Year: 2017
Venue: Journal of Cardiovascular Medicine (Hagerstown, Md.)
URL: https://www.semanticscholar.org/paper/1685069e7fbb47642dbd475d1b5cca90133ea1c6
DOI: 10.2459/JCM.0000000000000589
PMID: 29176389
PMCID: 5732648
Citations: 50
Influential citations: 1
Summary: This document reflects the multidisciplinary, ‘real-world’ experience required when implementing genetic testing in cardiomyopathies and arrhythmic syndromes, along the recommendations of various guidelines.
Evidence snippets:
Snippet 1 (score: 0.562) > Inherited cardiac diseases comprise a wide and heterogeneous spectrum of diseases of the heart, including the cardiomyopathies and the arrhythmic diseases in structurally normal hearts, that is, channelopathies. 1 With a combined estimated prevalence of 3% in the general population, 1 these conditions represent a relevant epidemiological entity worldwide, and are a major cause of cardiac morbidity and mortality in the young. The extraordinary progress achieved in molecular genetics over the last three decades has unveiled the complex molecular basis of many familial cardiac conditions, paving the way for routine use of gene testing in clinical practice. According to the European Society of Cardiology classification, cardiomyopathies are divided into dilated cardiomyopathy (DCM), hypertrophic (HCM), arrhythmogenic right ventricular (ARVC), restrictive and unclassified, although in practice there may be extensive overlap between these phenotypes. 2 The hypokinetic nondilated cardiomyopathy has been recently added to the prior major phenotypes. 3 The American Heart Association advanced a gene-based classification 4 so that HCM was viewed as a disease of the sarcomere 5 and ARVC as a disease of intercellular junctions, caused by mutations in genes encoding desmosomal proteins. 6,7 The genetics of familial DCM is far more heterogeneous: currently, DCM mutations have been described in genes encoding cytoskeletal, sarcomeric, desmosomal, nucleoskeletal, mitochondrial, and calcium handling proteins. 8 Additionally, sarcomere mutations have been identified in association with more complex disorders of cardiac structure and function, including restrictive physiology and left ventricular noncompaction. 4 In the same manner, ARVC e DCM phenotypes can be a different expression of variants in the same genes (Lamin A, Filamin C, and desmosomal genes). 7 Channelopathies, generally caused by mutations in proteins constituting or regulating cardiac ion channels, include the long-Q waves and T waves (QT) syndrome (LQTS), the short-QT syndrome (SQTS), Brugada syndrome (BrS), and

[16] Experimental models of spontaneous ventricular arrhythmias and of sudden cardiac death.

Authors: M. Štengl
Year: 2010
Venue: Physiological research
URL: https://www.semanticscholar.org/paper/2d6baf492e82162573b5c2be03a82a8d95b314fd
DOI: 10.33549/PHYSIOLRES.932001
PMID: 20626217
Citations: 23
Summary: In this review, a number of experimental animal models with high incidence of sudden cardiac death were developed and are intensively studied to get new insights into theudden cardiac death mechanisms.
Evidence snippets:
Snippet 1 (score: 0.560) > Arrhythmogenic right ventricular cardiomyopathy is an inherited cardiac disease associated with substantial cardiovascular morbidity and sudden death in young people (Thiene et al. 1988). Causative mutations were identified in genes encoding desmosomal proteins (Basso et al. 2009). A spontaneous, genetically transmitted model of arrhythmogenic right ventricular cardiomyopathy, closely resembling the human disease, was described in boxer dogs (Basso et al. 2004). Clinical events included sudden death, ventricular arrhythmias of suspected right ventricular origin, syncope and heart failure. Severe right ventricular myocyte loss with replacement by fatty or fibrofatty tissue was present. The cardiomyopathy in the model was shown to be associated with a substantial loss of gap junction plaques as well as with remodeling of other intercalated disc structures (Oxford et al. 2007). Calstabin2 deficiency associated with a significantly increased open probability of single sarcoplasmic reticulum release channels was also identified and suggested as a potential mechanism for calcium leak-induced ventricular arrhythmias in these dogs (Oyama et al. 2008).

[17] Extracellular vesicles in cardiomyopathies: A narrative review

Authors: A. Rizzuto, A. Faggiano, C. Macchi, S. Carugo, C. Perrino et al.
Year: 2023
Venue: Heliyon
URL: https://www.semanticscholar.org/paper/d9f9d3f5e11a4f42af7d1ead3cff3c874fff64a4
DOI: 10.1016/j.heliyon.2023.e23765
PMID: 38192847
PMCID: 10772622
Citations: 5
Influential citations: 1
Summary: The aims of this narrative review are to elucidate the potential role of EVs in the paracrine cell-to-cell communication among cardiac tissue compartments, in aiding the diagnosis of the diverse subtypes of cardiomyopathies in a minimally invasive manner, and to address whether certain molecular and phenotypical characteristics of EVs may correlate with cardiomyopathy disease phenotype and severity.
Evidence snippets:
Snippet 1 (score: 0.559) > Cardiomyopathies refer to myocardial disorders affecting the heart muscle, in which structural and functional abnormalities are observed, in the absence of diseases such as coronary artery disease, hypertension, valvular disease, or congenital heart disease that could account for the observed abnormalities. According to the 2023 European Society of Cardiology (ESC) guidelines for the management of cardiomyopathies, morphological traits (ventricular hypertrophy: left and/or right; ventricular dilation: left and/or right; non-ischemic ventricular scar) and functional characteristics (global and/or regional ventricular systolic and/or diastolic dysfunction) are clinically employed to categorize five distinct cardiomyopathy phenotypes: hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), non-dilated left ventricular cardiomyopathy (NDLVC), arrhythmogenic right ventricular cardiomyopathy (ARVC), and restrictive cardiomyopathy (RCM). Furthermore, the guidelines also specify the existence of syndromic and metabolic cardiomyopathies, including Anderson-Fabry disease, RASopathies, Friedreich ataxia, and Glycogen storage disorders [4]. > Whilst this phenotypic description is essential in paving the diagnostic and therapeutic pathway, the exact evolving nature of cardiomyopathies, along with their underlying aetiological complexities, are yet to be fully elucidated [5]. Within this context, biomarkers represent putative tools for identifying high-risk patients in a prompt manner, unveiling potential risk associations with disease progression and outcomes, and may also provide insights on unexplored molecular mechanisms at the basis of the pathophysiology of these disorders. > Thus, the aim of the present narrative review is to summarize the current knowledge on EVs in the setting of cardiomyopathies and to elucidate whether certain molecular and phenotypical characteristics of EVs (e.g., miRNA content) may correlate with cardiomyopathy phenotypes and severity.

[18] Familial Arrhythmogenic Cardiomyopathy: Clinical Determinants of Phenotype Discordance and the Impact of Endurance Sports

Authors: S. Costa, A. Gasperetti, A. Medeiros-Domingo, D. Akdis, C. Brunckhorst et al.
Year: 2020
Venue: Journal of Clinical Medicine
URL: https://www.semanticscholar.org/paper/cfa322e3e3e111e155b2634afedc42ee1aa5c0bc
DOI: 10.3390/jcm9113781
PMID: 33238575
PMCID: 7700696
Citations: 11
Summary: Different phenotypic expression profiles of ACM are analyzed in the context of the same familial genetic mutation by studying nine adult cases from four different families with four different familial variants from the Swiss Arrhythmogenic Right Ventricular Cardiomyopathy Registry.
Evidence snippets:
Snippet 1 (score: 0.558) > Arrhythmogenic cardiomyopathy (ACM) is primarily a familial disease with autosomal dominant inheritance. Incomplete penetrance and variable expression are common, resulting in diverse clinical manifestations. Although recent studies on genotype–phenotype relationships have improved our understanding of the molecular mechanisms leading to the expression of the full-blown disease, the underlying genetic substrate and the clinical course of asymptomatic or oligo-symptomatic mutation carriers are still poorly understood. We aimed to analyze different phenotypic expression profiles of ACM in the context of the same familial genetic mutation by studying nine adult cases from four different families with four different familial variants (two plakophilin-2 and two desmoglein-2) from the Swiss Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) Registry. The affected individuals with the same genetic variants presented with highly variable phenotypes ranging from no disease or a classical, right-sided disease, to ACM with biventricular presentation. Moreover, some patients developed early-onset, electrically unstable disease whereas others with the same genetic variants presented with late-onset electrically stable disease. Despite differences in age, gender, underlying genotype, and other clinical characteristics, physical exercise has been observed as the common denominator in provoking an arrhythmic phenotype in these families.

[19] Altered Electrical, Biomolecular, and Immunologic Phenotypes in a Novel Patient-Derived Stem Cell Model of Desmoglein-2 Mutant ARVC

Authors: Robert N Hawthorne, A. Blazeski, Justin Lowenthal, Suraj Kannan, R. Teuben et al.
Year: 2021
Venue: Journal of Clinical Medicine
URL: https://www.semanticscholar.org/paper/6da345fa7e27ceec663bb0cbe8949a5e52f4f9a7
DOI: 10.3390/jcm10143061
PMID: 34300226
PMCID: 8306340
Citations: 36
Influential citations: 1
Summary: A novel human induced pluripotent stem cell-derived cardiomyocyte model of ARVC from a patient with a c.2358delA variant in desmoglein-2 (DSG2) found DSG2Mut hiPSC-CMs could underlie early mechanisms of disease manifestation in ARVC patients.
Evidence snippets:
Snippet 1 (score: 0.555) > Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited, progressive arrhythmogenic cardiomyopathy (ACM) characterized by cardiomyocyte death and fibrofatty scarring in the ventricular myocardium. Clinically, patients with ARVC develop ventricular arrhythmias which often present more frequently as the disease progresses. > ARVC is estimated to account for more than 10% of all cardiovascular deaths in patients younger than 65 years old and is a leading cause of sudden cardiac death (SCD) in young athletes [1][2][3]. ARVC prevalence is approximately 1:1000-1:5000, and patients are typically diagnosed in young adulthood; diagnosis before puberty is extremely rare [4][5][6]. > While the pathophysiology underlying ARVC is still poorly understood, there has been general scientific consensus that the common final pathway of the disease involves the disruption of the cardiac desmosome, a cellular structure present at the intercalated disc that is critical for intercellular mechanical and electrical coupling between cardiomyocytes [7,8]. Pathogenic variants in any of the five cardiac desmosomal genes -plakoglobin (JUP), plakophilin-2 (PKP2), desmoglein-2 (DSG2), desmoplakin (DSP) and desmocollin-2 (DSC2)-account for more than 60% of inherited ARVC and have a combined estimated prevalence of approximately 1.2 per 1000 in the general population [9]. Among these, PKP2 and DSG2 are the first and second most common variants, respectively [6,10]. > Determining the pathogenic mechanisms underlying ARVC has proven difficult. The study of human tissue is challenging, as ARVC is frequently diagnosed in later stages of disease (e.g., myocardial scarring) when retrieval of a myocardial biopsy presents significant risk of cardiac perforation.

[20] Misdiagnosed myocarditis in arrhythmogenic cardiomyopathy induced by a homozygous variant of DSG2: a case report

Authors: Xuwei Liu, Y. Zhang, Wen‐Jing Li, Qian Zhang, Lei Zhou et al.
Year: 2023
Venue: Frontiers in Cardiovascular Medicine
URL: https://www.semanticscholar.org/paper/1236e1d0916ff4dccfecafe269c149a1847b4987
DOI: 10.3389/fcvm.2023.1150657
PMID: 37288269
PMCID: 10242036
Citations: 5
Summary: A rare pediatric case initially presenting as myocarditis that transitioned into ACM during follow-up is reported, expanding the clinical feature spectrum of DSG2-associated ACM at an early age.
Evidence snippets:
Snippet 1 (score: 0.553) > Misdiagnosed myocarditis in arrhythmogenic cardiomyopathy induced by a homozygous variant of DSG2: a case report 1. Introduction Arrhythmogenic right ventricular cardiomyopathy (ARVC, OMIM:#610476) is an inherited heart muscle disease characterized by the loss of the ventricular myocardium and fibrofatty replacement, which predisposes patients to fatal ventricular arrhythmias and sudden cardiac death (SCD) (1,2). A genetic etiology has been identified for most inherited cardiovascular diseases, especially cardiomyopathies, with the rapid development of sequencing techniques. Regarding the molecular mechanism, ARVC has been identified as being related to pathogenetic variants in desmosomes and adherens junctions, which are critical for establishing cell-cell junctions and maintaining intercellular communication (3,4). Thus, the disease group ACM should be considered to define the broader spectrum of the phenotypic expressions of the disease (4). From a molecular perspective, multiple genes encoding desmosomal proteins, such as plakophilin-2 (PKP2), desmoplakin (DSP), DSG2, desmocollin (DSC2), and plakoglobin (JUP), account for 50% of patients with ACM in different cohorts (5,6). However, there are other genetic (non-desmosomal) and non-genetic causes of the disease. The non-desmosomal genes include DES, LMNA, SCN5A, PLN, TMEM43, and TGFB3, which are not involved in the molecular formation of desmosomes and participate in several types of ARVC origins (2). The inclusion of sarcomere-, ion transporter-, and cytokine-related genes would increase the percentage of patients positive for molecular characterization. However, the incomplete dominance and variable expressiveness of certain variants suggest that environmental factors play an important role. Initially, ARVC was considered to mainly cause right ventricular lesions and impair the function of the right ventricle.

Notes

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Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC): Comprehensive Disease Research Report

claude-haiku-4-5-20251001, claude-sonnet-5 2026-08-08T04:11:26.925532

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC): Comprehensive Disease Research Report

1. Disease Information

Overview. Arrhythmogenic right ventricular cardiomyopathy (ARVC), now more broadly termed arrhythmogenic cardiomyopathy (ACM) to reflect biventricular and left-dominant phenotypic variants, is a heritable heart muscle disease characterized by progressive fibrofatty replacement of ventricular myocardium, predominantly affecting the right ventricle (RV), though left ventricular (LV) and biventricular forms are increasingly recognized. The disease is a leading cause of sudden cardiac death (SCD) in young people and athletes, often presenting with ventricular arrhythmias that may precede overt structural changes detectable on imaging. It is fundamentally a "disease of the desmosome" in the majority of genotyped cases, reflecting pathogenic variants in genes encoding cardiac desmosomal proteins that mediate mechanical cell-cell adhesion between cardiomyocytes, though non-desmosomal genetic causes (e.g., in genes encoding intermediate filament, nuclear envelope, or ion channel proteins) are also described.

Key identifiers: - OMIM: ARVC is genetically heterogeneous, with multiple OMIM phenotype entries corresponding to different loci/genes: ARVC1 (OMIM #107970, TGFB3), ARVC2 (OMIM #600996, RYR2), ARVC3 (OMIM #602086), ARVC4 (OMIM #602087, TTN), ARVC5 (OMIM #604400, TMEM43), ARVC6 (OMIM #604401), ARVC7 (OMIM #609160, DES), ARVC8 (OMIM #607450, DSP), ARVC9 (OMIM #609040, PKP2), ARVC10 (OMIM #610193, DSG2), ARVC11 (OMIM #610476, DSC2), ARVC12 (OMIM #611528, JUP), ARVC13 (OMIM #615616, unknown), and Naxos disease (OMIM #601214, JUP-related recessive cardiocutaneous syndrome) and Carvajal syndrome (OMIM #605676, DSP-related). - Orphanet: ORPHA:247 (Arrhythmogenic right ventricular cardiomyopathy) - MONDO: MONDO:0016587 is used in many ontology resources for ARVC (curators should verify against the local MONDO adapter before use, per dismech ontology practice, rather than assuming this ID is exact). - ICD-10: I42.8 (Other cardiomyopathies) is the commonly assigned code, as ICD-10 lacks an ARVC-specific code; ICD-11 includes more granular cardiomyopathy codes under BC43. - MeSH: D029094 (Arrhythmogenic Right Ventricular Dysplasia) - HPO term for the phenotype itself: HP:0031311 (Arrhythmogenic right ventricular cardiomyopathy) — curators should verify current HPO term ID.

Synonyms: Arrhythmogenic right ventricular dysplasia (ARVD); arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C); arrhythmogenic cardiomyopathy (ACM, the modern umbrella term encompassing right-dominant, biventricular, and left-dominant forms); Naxos disease (autosomal recessive cardiocutaneous variant with palmoplantar keratoderma and woolly hair); Carvajal syndrome (DSP-related left-dominant recessive cardiocutaneous variant).

Evidence basis. Most foundational literature is derived from aggregated disease-level resources: multi-center registries (e.g., the North American ARVC Registry, Johns Hopkins ARVC/C Program registry), family/pedigree studies, and genotype-phenotype correlation cohorts, supplemented increasingly by individual-patient genomic and EHR data as genetic testing has become standard of care.

2. Etiology

Primary causes. ARVC/ACM is a genetic disease of cell-cell junctions — predominantly desmosomal — in the majority of index cases where a pathogenic variant is identified (roughly 50-60% of clinically definite cases in most cohorts, though gene detection rates vary by cohort ascertainment). The prevailing "final common pathway" hypothesis holds that desmosomal dysfunction destabilizes intercalated discs, leading to cardiomyocyte detachment (particularly under the mechanical stress of exercise), cell death, fibrofatty replacement, and consequent electrical instability and structural remodeling. A parallel and complementary mechanistic thread implicates disrupted Wnt/β-catenin signaling — displaced plakoglobin (a desmosomal and Wnt-pathway shared protein) translocates to the nucleus, suppressing canonical Wnt signaling and promoting adipogenic and fibrogenic gene expression programs in cardiac progenitor/mesenchymal populations (Garcia-Gras et al., PMID:16467587, demonstrated this mechanism in a JUP-related mouse model).

Genetic risk/causal factors: - PKP2 (plakophilin-2): The single most commonly mutated gene, accounting for ~25-45% of genotyped cases in Western cohorts (autosomal dominant). - DSP (desmoplakin): Associated with both right-dominant and, notably, left-dominant/biventricular arrhythmogenic cardiomyopathy; DSP cardiomyopathy has a distinct "hot phase" myocarditis-like presentation with troponin release. - DSG2 (desmoglein-2), DSC2 (desmocollin-2): Less common desmosomal genes. - JUP (plakoglobin): Autosomal dominant forms and, in the homozygous/compound heterozygous state, Naxos disease. - TMEM43: Associated with a particularly malignant, highly penetrant form (Newfoundland variant, p.S358L) with high SCD risk. - Non-desmosomal genes: DES (desmin), TTN (titin), PLN (phospholamban, p.R14del founder variant especially in Dutch populations, associated with both DCM and ACM phenotypes), RYR2 (ryanodine receptor 2, historically linked to "ARVC2"/effort-induced polymorphic VT overlapping with CPVT), LMNA, FLNC (filamin C, associated with left-dominant arrhythmogenic cardiomyopathy and high arrhythmic risk), CDH2 (N-cadherin), CTNNA3 (α-T-catenin), SCN5A (overlap with Brugada/conduction disease phenotypes), and TGFB3. - Inheritance pattern: Predominantly autosomal dominant with incomplete and age-related penetrance and highly variable expressivity; autosomal recessive forms (Naxos, Carvajal) are associated with cardiocutaneous phenotypes. - Digenic/compound heterozygous disease burden: A substantial minority of patients carry more than one pathogenic/likely pathogenic variant (often in different desmosomal genes), which correlates with more severe and earlier-onset disease — this is a well-documented genetic modifier phenomenon in ARVC (Rigato et al. and Bhonsale et al. literature; specific PMIDs should be verified during curation).

Environmental/lifestyle risk factors: - Endurance/competitive exercise is the most robustly documented environmental risk factor — it accelerates disease onset, penetrance, and progression, and increases risk of malignant ventricular arrhythmia and SCD, particularly in genotype-positive individuals. This is a cornerstone finding across multiple cohorts (e.g., James et al., Circulation, and related work from the Johns Hopkins registry). - Age and sex: Male sex is associated with higher penetrance and more severe phenotype expression in most (though not all) genetic subtypes; typical age of symptom onset is adolescence to middle adulthood (commonly 20s-40s), with rare pediatric presentations. - Family history: A first-degree relative with ARVC or premature SCD is a major risk indicator and is incorporated into the 2010 Task Force diagnostic criteria as a minor/major criterion.

Protective factors: Restriction from competitive/endurance exercise in genotype-positive individuals is the principal actionable "protective" intervention supported by observational cohort data, though this is a management recommendation rather than a biological protective factor per se. No specific protective genetic variants are well established in the literature at a level suitable for confident citation; curators should search ClinVar/gnomAD/GWAS Catalog for modifier alleles rather than assume none exist.

Gene-environment interaction. The clearest G×E interaction in ARVC is the exercise-genotype interaction described above: mechanical/hemodynamic stress on a desmosomally-weakened intercalated disc accelerates myocyte detachment and disease progression, meaning the same pathogenic variant produces markedly different phenotypic severity depending on exercise exposure — a pattern well supported by both human cohort data and mouse models (e.g., Kirchhof et al., Circulation 2006, PMID:16769908, on exercise effects in a heterozygous plakoglobin-deficient mouse model).

3. Phenotypes

ARVC/ACM phenotypes span structural, electrical, and (in syndromic recessive forms) cutaneous domains.

Clinical signs/symptoms: - Palpitations — frequent presenting symptom, related to ventricular ectopy/VT (suggested HP term: HP:0001962 Palpitations) - Syncope — exertional or arrhythmic syncope is a major diagnostic criterion and high-risk marker (HP:0001279 Syncope) - Sudden cardiac death / cardiac arrest — may be the first manifestation, especially in young athletes (HP:0001645 Sudden cardiac death, if available; otherwise use relevant HPO death/arrhythmia terms) - Ventricular tachycardia, typically with left bundle branch block (LBBB) morphology reflecting RV origin (HP:0004756 Ventricular tachycardia) - Right ventricular dilation/dysfunction (HP:0011663 Right ventricular dilatation; HP:0001635 Congestive heart failure in advanced disease) - Epsilon waves on ECG — a classic, highly specific but insensitive major Task Force criterion - T-wave inversion in right precordial leads (V1-V3) — common ECG finding, a major/minor criterion depending on age and QRS duration - Fibrofatty myocardial replacement on imaging/histology — the structural hallmark - Heart failure symptoms in advanced/burnt-out phase, sometimes indistinguishable from dilated cardiomyopathy

Cutaneous phenotypes (syndromic recessive forms): - Woolly hair (HP:0002415) and palmoplantar keratoderma (HP:0000982) — cardinal features of Naxos disease (JUP) and, to a variable degree, Carvajal syndrome (DSP)

Phenotype characteristics: - Age of onset: Classically second to fourth decade of life; the disease is thought to evolve through phases — a "concealed" subclinical phase (structurally near-normal but arrhythmia risk present), an "overt electrical" phase, and a "structural/heart failure" phase — as described in the classic natural history model (Thiene, Basso, Corrado literature from the Padua group). - Severity/progression: Highly variable; disease is generally progressive but rate varies considerably by genotype (e.g., TMEM43 p.S358L and compound/digenic desmosomal genotypes associate with more aggressive, earlier disease), sex, and exercise exposure. - Frequency among affected individuals: Symptom/sign frequencies vary substantially by cohort and genotype; T-wave inversion in right precordial leads is reported in roughly 50-85% of definite ARVC cases depending on series; epsilon waves are far less common (reported in a minority, often <30%, of cases, being highly specific but insensitive).

Quality of life impact. Disease burden includes psychological impact of implantable cardioverter-defibrillator (ICD) therapy (shocks, anxiety, activity restriction), exercise restriction itself (particularly impactful for athletes), and progression to heart failure in advanced cases requiring transplantation. Formal EQ-5D/SF-36 data specific to ARVC populations are less commonly reported in the mainstream ARVC literature compared to more common cardiomyopathies; curators should search specifically for ARVC-focused QOL studies (e.g., studies of ICD recipients with ARVC) rather than assume generic cardiomyopathy QOL data applies uniformly.

4. Genetic/Molecular Information

Causal genes (desmosomal — "the big five"): - PKP2 (plakophilin-2) — HGNC:9024; most common - DSP (desmoplakin) — HGNC:3052 - DSG2 (desmoglein-2) — HGNC:3049 - DSC2 (desmocollin-2) — HGNC:3036 - JUP (plakoglobin/junction plakoglobin) — HGNC:6207

Non-desmosomal genes: - TMEM43 — HGNC:19073 - DES (desmin) — HGNC:2770 - TTN (titin) — HGNC:12403 - PLN (phospholamban) — HGNC:9091 - RYR2 (ryanodine receptor 2) — HGNC:10484 - FLNC (filamin C) — HGNC:3756 - LMNA — HGNC:6636 - CDH2 (N-cadherin) — HGNC:1759 - CTNNA3 (α-T-catenin) — HGNC:2510 - SCN5A — HGNC:10593 - TGFB3 — HGNC:11768

Variant classification and type. Pathogenic variants in PKP2 are predominantly truncating (nonsense, frameshift, canonical splice-site) loss-of-function variants, consistent with a haploinsufficiency mechanism, whereas DSG2, DSC2, and DSP more commonly harbor missense as well as truncating variants, and some act via dominant-negative mechanisms disrupting desmosome assembly. TMEM43 disease is dominated by a single recurrent founder missense variant (p.S358L) in the Newfoundland population. ACMG/AMP classification (pathogenic, likely pathogenic, VUS) should be verified per-variant in ClinVar/ClinGen, as classification is variant-specific.

Allele frequency. Pathogenic ARVC variants are individually rare in population databases (gnomAD), consistent with a rare Mendelian disease under purifying selection, though the PLN p.R14del variant shows a founder effect with elevated frequency in the Dutch/Netherlands population specifically.

Somatic vs. germline. ARVC-causing variants are germline; no significant somatic mosaicism literature specific to ARVC pathogenesis is well established (in contrast to some other inherited arrhythmia syndromes), though germline mosaicism in unaffected parents of de novo cases has been reported anecdotally.

Functional consequences. The dominant mechanistic model is haploinsufficiency/loss of desmosomal protein function leading to weakened intercalated disc mechanical coupling, though dominant-negative effects (particularly for missense variants disrupting protein-protein interaction domains) are also documented. A gain-of-function/dominant-negative mechanism is also implicated for some DSP variants causing the "hot phase" inflammatory presentation.

Modifier genes/factors. Digenic/compound heterozygosity across desmosomal genes is the best-documented genetic modifier of severity. TTN variants and other "second hits" have also been proposed as disease modifiers in some cohorts.

Epigenetic information. Specific well-characterized epigenetic (DNA methylation/histone) contributions to ARVC pathogenesis are not a major established pillar of the literature relative to the structural/desmosomal mechanism; curators should search ENCODE/Roadmap Epigenomics/DiseaseMeth specifically if this dimension is needed, as it is not a primary focus of current mechanistic literature.

Chromosomal abnormalities. ARVC is not typically caused by large-scale chromosomal abnormalities (aneuploidy, translocations); it is predominantly a single-gene/point-variant disease. No major DECIPHER-cataloged CNV syndrome is classically associated with ARVC as a primary feature.

5. Environmental Information

Environmental/lifestyle factors. As above, competitive and endurance exercise is the dominant, best-documented environmental modifier — it both unmasks/accelerates disease in genotype-positive individuals and is independently associated with an ARVC-like phenocopy in some non-genotyped athletes ("exercise-induced arrhythmogenic remodeling"), a concept debated in the literature (distinguishing true genetic ARVC from an acquired exercise-induced RV remodeling phenotype in endurance athletes is an active area of clinical and research interest).

Infectious agents. Not a primary etiological category for ARVC; however, myocarditis-like presentations (particularly in DSP-related disease, the "hot phase") can clinically mimic viral myocarditis and are sometimes triggered by or co-occur with viral infection, though this is a disease-manifestation overlap rather than an established infectious cause.

6. Mechanism / Pathophysiology

Causal chain overview. Desmosomal gene mutation → destabilized intercalated disc mechanical junctions → cardiomyocyte detachment/death under mechanical (especially exercise-induced) stress → myocardial injury and inflammatory response → replacement fibrosis and fibroadipogenesis (with displaced plakoglobin suppressing canonical Wnt/β-catenin signaling and promoting adipogenic/fibrogenic transcriptional programs, per Garcia-Gras et al. 2006, PMID:16467587) → disruption of gap junction (connexin-43) localization and reduced conduction velocity → re-entrant substrate for ventricular arrhythmia → progressive RV (and often LV) structural remodeling, dilation, and dysfunction → heart failure in advanced disease.

Molecular pathways: - Desmosome-intercalated disc mechanical coupling pathway (structural) - Wnt/β-catenin signaling — canonical pathway suppression via nuclear plakoglobin translocation (KEGG Wnt signaling pathway; GO term suggestion: GO:0060070 canonical Wnt signaling pathway, with a NEGATIVE modifier) - Gap junction remodeling — connexin-43 (GJA1) lateralization and reduced expression at intercalated discs, contributing to conduction slowing (Cx43-related literature is well established in ARVC mechanistic studies) - Calcium handling dysregulation — particularly relevant in RYR2-related and PLN-related forms, overlapping with catecholaminergic polymorphic VT mechanisms

Cellular processes: Apoptosis and/or necroptosis of cardiomyocytes under mechanical stress; adipogenic transdifferentiation of cardiac progenitor or resident mesenchymal populations; fibroblast activation and fibrosis (overlapping conceptually with the dismech fibrotic_response module pattern: tissue injury → inflammation → mesenchymal activation → myofibroblast → excessive ECM deposition); chronic low-grade inflammation, particularly pronounced in DSP-related "hot phase" disease with lymphocytic infiltration resembling myocarditis.

Protein dysfunction. Loss of normal desmosomal plaque assembly (PKP2, DSG2, DSC2, DSP, JUP proteins normally form a multiprotein complex linking cadherins to the intermediate filament cytoskeleton); structural destabilization reduces mechanical resilience of the intercalated disc under cyclic mechanical load.

Tissue damage mechanisms. Mechanical stress-induced myocyte injury (particularly at the RV free wall, which is thin-walled and mechanically vulnerable), followed by an inflammatory/reparative fibrofatty replacement process rather than typical ischemic necrosis.

Immune system involvement. Myocardial inflammatory infiltrates (lymphocytic myocarditis-like pattern) are documented, especially in DSP cardiomyopathy "hot phase" episodes; autoimmune/autoantibody mechanisms (e.g., anti-desmoglein-2 antibodies) have also been proposed in some studies as contributing to disease propagation, though this remains an area of ongoing investigation rather than settled mechanism.

Biochemical abnormalities. Reduced/mislocalized desmosomal protein expression at the intercalated disc (demonstrable by endomyocardial biopsy immunohistochemistry, e.g., reduced plakoglobin signal — a research/diagnostic tool explored by the Toronto/Padua groups); altered connexin-43 distribution.

Molecular profiling. Transcriptomic studies of ARVC myocardium (from explanted hearts) show upregulation of adipogenic and fibrogenic gene programs and downregulation of Wnt target genes; proteomic and single-cell/spatial transcriptomic characterization of ARVC myocardium is an active but still maturing area (search GEO, Human Cell Atlas heart datasets for current single-cell cardiomyocyte/fibroblast/adipocyte composition data in ARVC hearts).

GO/CL term suggestions: GO:0007163 (cell adhesion mediated by integrin — related but not exact; better: GO:0030057 desmosome), GO:0016337 (cell-cell adhesion), GO:0060070 (canonical Wnt signaling pathway), CL:0000746 (cardiac muscle cell / cardiomyocyte), CL:0000057 (fibroblast), CL:0000136 (adipocyte).

7. Anatomical Structures Affected

Organ level. Primary: right ventricle (RV), classically the "triangle of dysplasia" (RV inflow tract, outflow tract, and apex). Left ventricular involvement occurs in biventricular and left-dominant forms (notably DSP- and FLNC-related disease), which is now recognized as common enough to justify the broader "arrhythmogenic cardiomyopathy" nomenclature. Secondary involvement: heart failure sequelae affecting other organs in advanced disease (hepatic congestion, renal hypoperfusion).

UBERON suggestions: UBERON:0002080 (heart right ventricle... actually UBERON:0002080 is "cardiac ventricle"; right ventricle-specific term is UBERON:0002080's child), UBERON:0015230 (myocardium of right ventricle) — curators should verify exact UBERON IDs via OAK lookup rather than trust from memory.

Tissue/cell level. Myocardium (cardiomyocytes, CL:0000746) undergoing progressive replacement by fibrous connective tissue (fibroblasts/myofibroblasts, CL:0000057) and adipose tissue (adipocytes, CL:0000136); the epicardial-to-endocardial gradient of fibrofatty infiltration is a classic histopathological feature.

Subcellular level. Intercalated disc (a specialized cell-cell junction complex); desmosome (GO:0030057, cellular component); gap junction (GO:0005921) — connexin-43 mislocalization from gap junctions is well documented.

Cutaneous involvement (syndromic forms). Skin (palms/soles — palmoplantar keratoderma) and hair follicles (woolly hair) in Naxos disease and, variably, Carvajal syndrome, reflecting the shared desmosomal biology between cardiac intercalated discs and epidermal desmosomes.

Localization/laterality. RV-predominant in classic ARVC; biventricular or LV-dominant in DSP/FLNC-related disease; regional patchy involvement (not diffuse) is characteristic, contributing to the classic "epicardial to endocardial," patchy wavefront pattern of fibrofatty replacement.

8. Temporal Development

Onset. Typically manifests in adolescence through middle adulthood (most commonly 20s-40s); pediatric-onset and elderly-onset presentations are less common but reported. Onset is often insidious, with a "concealed phase" preceding overt clinical manifestation.

Progression — the classic four-phase natural history model (Thiene/Basso/Corrado, Padua group, foundational literature): 1. Concealed phase — subtle or absent structural abnormalities; SCD (often exercise-related) may be the first and only manifestation in this phase, particularly in young athletes. 2. Overt electrical disorder phase — symptomatic ventricular arrhythmias with clear structural RV abnormalities. 3. Right ventricular failure phase — progressive RV pump failure with preserved LV function. 4. Biventricular pump failure phase — end-stage disease with both ventricles failing, potentially indistinguishable from dilated cardiomyopathy.

Progression rate and course. Variable — generally slowly progressive over years to decades, but genotype (e.g., TMEM43, compound/digenic desmosomal variants), sex (male), and exercise exposure accelerate progression. Disease course is chronic and lifelong; spontaneous remission does not occur, though disease activity (especially inflammatory "hot phase" episodes in DSP disease) can fluctuate episodically.

Critical periods. Adolescence/young adulthood during competitive sports participation represents a key window of vulnerability, both because arrhythmic risk peaks around this exercise-intensive period and because this is when many genotype-positive individuals first become symptomatic or are identified via family cascade screening.

9. Inheritance and Population

Epidemiology. Estimated prevalence commonly cited in the literature is approximately 1 in 1,000 to 1 in 5,000 in the general population, though this figure is imprecise and varies by region and case ascertainment methodology; higher prevalence is reported in some endemic regions (e.g., the Veneto region of Italy, where the disease was first extensively characterized). ARVC is disproportionately represented among cases of SCD in young athletes in certain series (notably Italian autopsy-based athlete SCD studies from the Padua group), though the exact proportion varies by cohort and geography (US series generally attribute a smaller proportion of athlete SCD to ARVC compared to Italian series, a well-known geographic discrepancy in the literature).

Inheritance pattern. Predominantly autosomal dominant (most desmosomal gene forms); autosomal recessive in Naxos disease (JUP) and Carvajal syndrome (DSP), both associated with cardiocutaneous phenotypes.

Penetrance. Incomplete and age-related — penetrance increases with age, and is generally higher in males than females for most genotypes; PKP2 penetrance in particular is well documented as incomplete, meaning many genotype-positive family members remain asymptomatic or subclinical for years.

Expressivity. Highly variable, even within families carrying the identical pathogenic variant — a hallmark feature that has generated substantial modifier-gene and gene-environment interaction research (as above).

Genetic anticipation. Not a well-established feature of ARVC (unlike repeat-expansion disorders); not typically discussed in the mainstream literature.

Founder effects. TMEM43 p.S358L in the Newfoundland (Canada) population is the best-documented founder variant, associated with a highly penetrant, malignant phenotype particularly in males; PLN p.R14del founder variant in the Netherlands is associated with both ACM and DCM phenotypes.

Consanguinity role. Relevant specifically to the autosomal recessive forms (Naxos disease, first described in families from the Greek island of Naxos with elevated consanguinity; Carvajal syndrome, initially described in Ecuadorian families).

Sex ratio. Male predominance in symptomatic/clinically overt disease is well documented across most genetic subtypes, generally cited in the range of roughly 3:1 to 2:1 male:female in clinically ascertained cohorts, though exact ratios vary by study and genotype.

Geographic distribution. Well characterized as endemic/over-represented in the Veneto region of Italy (site of the foundational Padua-group pathological studies); Naxos disease geographically clustered on the Greek island of Naxos and other Greek islands; TMEM43 founder variant concentrated in Newfoundland, Canada.

10. Diagnostics

Diagnostic framework. Diagnosis is guided by the 2010 Task Force Criteria (TFC) (revised from the original 1994 criteria), which integrate six categories of evidence, each with major and minor criteria: (1) global/regional RV dysfunction and structural alterations (echocardiography, MRI, RV angiography); (2) tissue characterization (endomyocardial biopsy histology); (3) repolarization abnormalities (ECG T-wave inversion); (4) depolarization/conduction abnormalities (epsilon waves, prolonged terminal activation duration on signal-averaged ECG); (5) arrhythmias (VT with LBBB morphology, PVC burden); (6) family history/genetics. Diagnostic categories are combined into definite, borderline, or possible diagnosis based on point totals.

Imaging. - Cardiac MRI — gold-standard imaging modality, assessing RV/LV volumes, function, regional wall motion abnormalities, and late gadolinium enhancement (fibrofatty tissue characterization). - Echocardiography — first-line screening, assessing RV size/function and regional wall motion abnormalities. - RV angiography — historically used, now largely supplanted by MRI.

Electrophysiology. - 12-lead ECG — T-wave inversion in right precordial leads, epsilon waves, prolonged terminal activation duration. - Signal-averaged ECG (SAECG) — detects late potentials reflecting delayed, fragmented conduction in diseased myocardium. - Holter monitoring / exercise stress testing — quantifies PVC burden and detects exercise-induced ventricular arrhythmia. - Electroanatomic voltage mapping — identifies low-voltage scar regions corresponding to fibrofatty replacement, used both diagnostically and to guide ablation.

Biopsy/histopathology. Endomyocardial biopsy showing fibrofatty replacement of myocardium is a major Task Force criterion when quantitative histomorphometric thresholds are met, though biopsy has significant sampling-error limitations given the patchy, often epicardial-predominant nature of disease.

Genetic testing. - Recommended approach: targeted next-generation sequencing gene panels covering the desmosomal genes (PKP2, DSP, DSG2, DSC2, JUP) plus non-desmosomal genes (TMEM43, DES, TTN, PLN, RYR2, FLNC, LMNA, CDH2, CTNNA3) are standard first-line testing in patients meeting clinical Task Force criteria. - Single-gene testing may be appropriate for known familial variants (cascade testing). - Whole exome/genome sequencing is increasingly used, particularly in genotype-negative "definite" clinical cases or atypical presentations, to identify novel/non-canonical genes. - Chromosomal microarray, karyotyping, FISH, and mitochondrial DNA testing are not standard components of ARVC diagnostic workup given the single-gene point-variant nature of the disease.

Clinical criteria/differential diagnosis. Key differentials include idiopathic RV outflow tract VT (structurally normal heart, a benign arrhythmia that must be distinguished from early ARVC), sarcoidosis (can mimic ARVC with RV involvement and VT — "arrhythmogenic mimics" is a recognized diagnostic challenge), dilated cardiomyopathy (in advanced/biventricular ARVC), Brugada syndrome (some genetic and phenotypic overlap, particularly SCN5A-related cases), congenital heart disease with RV volume overload, and athletic RV remodeling ("athlete's heart").

Screening. Cascade genetic and clinical (ECG + echocardiography, ideally with periodic reassessment given age-related penetrance) screening of first-degree relatives of an affected proband is standard of care once a pathogenic variant is identified in an index case.

11. Outcome/Prognosis

Survival/mortality. With modern management (ICD therapy, exercise restriction, pharmacotherapy, ablation), annual mortality rates in genotype-positive/diagnosed cohorts have decreased substantially compared to historical (pre-ICD-era) cohorts, though ARVC remains an important cause of SCD in the young. Risk stratification for primary/secondary prevention ICD implantation is central to prognosis, incorporating factors such as prior sustained VT/VF, extensive RV/LV dysfunction, non-sustained VT burden, syncope, and genotype (e.g., multiple/compound desmosomal variants, TMEM43 founder variant carriers).

Morbidity. ICD-related morbidity (inappropriate shocks, lead complications, psychological burden) is a significant component of disease burden in this population; progression to heart failure requiring advanced therapies (including heart transplantation) occurs in a subset of patients, particularly those with the biventricular/burnt-out phenotype.

Complications. Ventricular arrhythmia/SCD, heart failure, and (in DSP "hot phase" disease) recurrent acute myocarditis-like episodes with troponin elevation and chest pain are the principal disease-specific complications.

Prognostic factors/biomarkers. Established clinical risk factors used in contemporary multivariable risk calculators (e.g., the ARVC risk calculator developed by the Johns Hopkins/multi-center collaboration) include: prior sustained ventricular arrhythmia, syncope, non-sustained VT, PVC burden, T-wave inversion extent, RV/LV ejection fraction, male sex, and proband status. Biomarker-based prognostication (e.g., natriuretic peptides, troponin during hot-phase episodes) is used adjunctively but is not a primary risk-stratification pillar comparable to the clinical/imaging/electrical factors above.

12. Treatment

Pharmacotherapy. - Beta-blockers — first-line antiarrhythmic and symptom-management therapy (NCIT term suggestion: NCIT:C15986 Pharmacotherapy; therapeutic_agent class NCIT:C2949 or specific beta-blocker CHEBI terms as appropriate). - Antiarrhythmic drugs — sotalol has historically been the most studied agent for ARVC-related VT suppression; amiodarone is also used, particularly in combination with beta-blockade or when sotalol is inadequate/contraindicated. - Heart failure pharmacotherapy (ACE inhibitors/ARBs, mineralocorticoid receptor antagonists, diuretics) in patients with RV or biventricular dysfunction/failure.

Interventional/device therapy. - Implantable cardioverter-defibrillator (ICD) — cornerstone of SCD prevention in high-risk patients (both primary and secondary prevention indications), guided by risk-stratification algorithms as above. - Catheter ablation (radiofrequency, endocardial and epicardial) — used for recurrent VT refractory to or as an adjunct to antiarrhythmic drugs and ICD therapy; epicardial ablation is particularly relevant given the epicardial-predominant nature of the arrhythmogenic substrate in many patients.

Surgical/advanced therapy. - Heart transplantation — reserved for end-stage biventricular heart failure refractory to medical/device therapy.

Supportive/behavioral. - Exercise restriction — a cornerstone, non-pharmacological management recommendation for genotype-positive individuals (both affected and at-risk asymptomatic carriers), given the strong exercise-disease progression relationship (NCIT term suggestion: NCIT:C181743 Behavioral Counseling, or a lifestyle-modification-specific term).

Experimental/emerging therapies. Active research areas include gene therapy approaches targeting specific desmosomal deficiencies (preclinical), small molecules targeting the Wnt/β-catenin pathway (e.g., SB216763, a GSK-3β inhibitor shown to rescue the ARVC phenotype in preclinical plakoglobin-deficient mouse models, per the Garcia-Gras et al. line of mechanistic work), and anti-inflammatory approaches for DSP "hot phase" disease; curators should search ClinicalTrials.gov directly for current NCT-registered trials, as this space evolves rapidly.

Treatment strategy. Management follows a risk-stratified algorithm: exercise restriction and beta-blockade for all affected/genotype-positive individuals; ICD implantation guided by validated risk calculators; antiarrhythmic drugs and/or catheter ablation for breakthrough arrhythmia; advanced heart failure therapy/transplantation for end-stage disease.

13. Prevention

Primary prevention. Not applicable in the traditional infectious-disease sense (this is a genetic disease), but pre-symptomatic identification via cascade genetic testing of relatives, combined with exercise restriction in genotype-positive individuals, functions as a primary preventive strategy against disease acceleration and first arrhythmic event.

Secondary prevention. Periodic clinical screening (ECG, echocardiography, and as appropriate cardiac MRI) of genotype-positive but phenotype-negative relatives, given age-related penetrance, to detect early disease before major arrhythmic events occur; participation in pre-participation athletic screening programs (notably the Italian model, which screens competitive athletes with ECG as part of a broader SCD-prevention strategy) has been credited with reduced ARVC-related athlete mortality in some studies from the Padua group, though this remains a subject of ongoing health-policy debate, particularly regarding cost-effectiveness and false-positive rates in other health systems (e.g., the US).

Tertiary prevention. ICD therapy and antiarrhythmic management to prevent SCD and disease complications in already-diagnosed patients; heart failure management to prevent/delay progression to transplantation.

Genetic counseling. Central to ARVC management given autosomal dominant inheritance with incomplete penetrance — counseling addresses recurrence risk, the rationale and limitations of cascade testing, reproductive options, and the psychological/lifestyle implications (particularly exercise restriction) of a positive genotype.

Public health / sports cardiology screening. Pre-participation cardiovascular screening programs for competitive athletes (protocols vary substantially by country/sporting body) represent the primary public-health-level intervention relevant to ARVC-related SCD prevention.

14. Other Species / Natural Disease

Boxer dogs are a well-recognized, naturally occurring large-animal model of arrhythmogenic right ventricular cardiomyopathy, historically termed "Boxer ARVC" — this is one of the best-characterized spontaneous veterinary parallels to the human disease, associated with a striatin (STRN) gene variant in some studied populations (search OMIA for the precise, current gene association, as this has been refined over time in the veterinary genetics literature). Naturally occurring ARVC-like disease has also been described in cats. These represent genuine spontaneous/naturally occurring veterinary disease rather than induced laboratory models, and are cataloged in OMIA (Online Mendelian Inheritance in Animals).

Comparative biology. The desmosomal cell-adhesion machinery is highly evolutionarily conserved across mammals, supporting good face-validity of both spontaneous animal disease and engineered rodent models for mechanistic study.

15. Model Organisms

Mouse models. - Heterozygous plakoglobin (Jup)-deficient mice — the foundational genetic mouse model (Garcia-Gras et al., PMID:16467587) demonstrating that Jup haploinsufficiency, combined with exercise (endurance training), produces the classic ARVC phenotype (RV dilation, fibrofatty replacement, arrhythmia), and that Wnt pathway restoration (via GSK-3β inhibition) rescues the phenotype — directly connecting mechanism to a therapeutic hypothesis. Kirchhof et al. (PMID:16769908) further characterized exercise-dependent electrophysiological remodeling in this model. - Desmoplakin (Dsp) cardiac-restricted knockout/mutant mice — recapitulate fibrofatty replacement, arrhythmia, and (in some models) the inflammatory "hot phase" phenotype relevant to human DSP cardiomyopathy. - PKP2 cardiomyocyte-specific knockout mice — used to study PKP2 haploinsufficiency/loss-of-function mechanisms, including roles in calcium handling and gap junction remodeling beyond pure mechanical coupling. - TMEM43 p.S358L knock-in mice — model the highly penetrant Newfoundland founder variant phenotype.

Zebrafish models. Used for select desmosomal and non-desmosomal gene studies given rapid generation time and amenability to genetic/chemical screening, though less extensively deployed for ARVC specifically compared to mouse models.

iPSC-derived cardiomyocyte models. Patient-derived and CRISPR-engineered induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) carrying desmosomal (PKP2, DSP, DSG2) and non-desmosomal (PLN, FLNC) pathogenic variants are widely used to model cell-autonomous phenotypes including abnormal desmosome assembly, adipogenic differentiation propensity, altered calcium handling, and arrhythmic electrophysiological phenotypes in vitro — an increasingly central platform for both mechanistic study and drug screening given the difficulty of studying the "second hit" of mechanical stress in a dish.

Model characteristics/limitations. Mouse models generally require an exercise or additional genetic "second hit" (e.g., combined with a second desmosomal mutation) to fully recapitulate the human phenotype, reflecting the multifactorial (genetic + mechanical stress) nature of human disease — a single heterozygous desmosomal mutation alone is often insufficient to produce a fully penetrant phenotype in mice at baseline, mirroring the incomplete penetrance seen in human carriers. iPSC-CM models, while excellent for cell-autonomous mechanism, cannot easily recapitulate the whole-organ mechanical stress, fibrosis, and in vivo arrhythmia substrate that define the clinical disease — an important human-model-fidelity caveat relevant to any hypothesis built primarily on iPSC-CM data (analogous to the HUMAN_MODEL_MISMATCH framing used in dismech curation for other diseases).

Resources. MGI (Mouse Genome Informatics) for mouse allele records (Jup, Dsp, Pkp2, Tmem43 knockout/knock-in strains); IMPC/KOMP for systematic knockout phenotyping data; ZFIN for zebrafish; Alliance of Genome Resources for cross-species orthology (e.g., confirming PKP2/DSP/JUP ortholog conservation across mouse, zebrafish, and human).

Citation Summary and Confidence Notes

This report draws on the well-established ARVC/ACM literature as understood through my training. High-confidence, specifically citable claims include the Garcia-Gras et al. 2006 (PMID:16467587) plakoglobin/Wnt mechanism paper and the Kirchhof et al. 2006 (PMID:16769908) exercise-mouse-model paper. Gene lists (PKP2, DSP, DSG2, DSC2, JUP, TMEM43, DES, TTN, PLN, RYR2, FLNC, LMNA, CDH2, CTNNA3, SCN5A, TGFB3), the 2010 Task Force Criteria framework, the four-phase natural history model (Thiene/Basso/Corrado, Padua group), Naxos disease and Carvajal syndrome as recessive cardiocutaneous variants, TMEM43 Newfoundland founder effect, PLN p.R14del Dutch founder effect, and Boxer dog ARVC as a natural veterinary model are all well-established facts in the cardiovascular genetics literature that I am highly confident in, though I was not able to run live PubMed/OMIM/Orphanet/HPO/gnomAD/ClinVar queries in this session to pull exact current PMIDs, precise OMIM/Orphanet/MONDO/HPO numeric IDs, or up-to-date prevalence/frequency statistics.

Important curation caveat: Several specific identifiers in this report (OMIM subtype numbers, the MONDO ID, exact HPO term IDs, precise UBERON IDs, and quantitative frequency/prevalence figures) should be independently verified via OAK/runoak lookups and live database queries (OMIM, Orphanet, ClinVar, gnomAD, HPO) before being committed to a dismech KB entry — consistent with the project's anti-hallucination SOP (§2, §2a of the dismech evidence guidelines) requiring that every PMID, snippet, and ontology term be independently verified against its primary source rather than trusted from a synthesized report. I was not able to perform that live verification in this session, so this report should be treated as a curation lead requiring the standard just fetch-reference / just validate-terms verification workflow, not as pre-verified ground truth.

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Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) — Comprehensive Disease Characteristics Report

openscientist-autonomous 59 citations 2026-07-26T07:54:02.136849

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) — Comprehensive Disease Characteristics Report

Target disease: Arrhythmogenic right ventricular cardiomyopathy MONDO ID: MONDO:0016587 · Category: Mendelian (autosomal dominant, desmosomal) Investigation: 5 iterations · 20 confirmed findings · 81 papers reviewed

Summary

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited myocardial disease defined by progressive fibrofatty replacement of the ventricular myocardium — classically the right ventricle — that creates an electrically unstable substrate producing ventricular arrhythmias, heart failure, and sudden cardiac death (SCD), especially in young people and endurance athletes. It is fundamentally a disease of the cardiac desmosome: pathogenic loss-of-function variants in desmosomal genes account for the majority of cases, with PKP2 (plakophilin-2) the single most common cause, followed by DSP, DSG2, DSC2, and JUP, plus important non-desmosomal causes including TMEM43, PLN, and FLNC. Desmosomal gene variants account for 67.4% of ARVC cases in cohort studies and 96.1% of pathogenic variants in ClinVar (PMID: 42366226).

Mechanistically, destabilization of the intercalated disc triggers a convergent signaling cascade: activation of the Hippo pathway (Merlin/NF2 → MST1/2 → LATS1/2 → YAP phosphorylation), suppression of canonical Wnt/β-catenin signaling via nuclear plakoglobin/YAP–β-catenin sequestration, and engagement of TGF-β signaling — together driving a pro-adipogenic, pro-fibrotic transcriptional program. A shared, mutation-agnostic downstream feature is downregulation of the gap-junction protein connexin-43 (Cx43), which contributes to arrhythmogenesis independent of the causal gene. Increasingly, ARVC is also recognized as an inflammatory cardiomyopathy with episodic "hot phases" that mimic myocarditis. The key environmental modifier is endurance/high-intensity exercise, which accelerates penetrance and arrhythmic risk in a dose-dependent manner and largely explains the observed male predominance.

Clinically, ARVC has a prevalence of ~1:2,000 to 1:5,000, presents typically between the second and fourth decades of life, and is diagnosed by the multiparametric 2010 modified Task Force Criteria and 2020 Padua criteria integrating imaging, ECG, tissue, arrhythmia, and genetic data. Management is currently palliative: exercise restriction, beta-blockers and antiarrhythmics, catheter ablation, and ICD implantation guided by the 2019 ARVC risk calculator, with heart transplantation reserved for end-stage disease. A new generation of AAV-based gene therapies — PKP2 gene replacement (LX2020) and mutation-agnostic Cx43 restoration — show strong preclinical efficacy and represent the first potentially disease-modifying treatments.

1. Disease Information

ARVC is an inherited cardiomyopathy characterized by progressive fibrofatty replacement of ventricular myocardium, ventricular arrhythmias, and increased sudden cardiac death risk. It was originally called arrhythmogenic right ventricular dysplasia (ARVD), later broadened to arrhythmogenic cardiomyopathy (ACM) to encompass left-dominant and biventricular forms; the 2023 ESC guidelines reintroduced "ARVC" specifically for fibrofatty right ventricular disease while using "non-dilated left ventricular cardiomyopathy" for left-sided phenotypes (PMID: 39980788).

Key identifiers: - MONDO: MONDO:0016587 - OMIM: ARVD1 (107970, TGFB3), ARVD2 (600996, RYR2), ARVD5 (604400, TMEM43), ARVD8 (607450, DSP), ARVD9 (609040, PKP2), ARVD10 (610193, DSG2), ARVD11 (610476, DSC2), ARVD12 (611528, JUP) - Orphanet: ORPHA:247 - ICD-10: I42.8 · ICD-11: BC43.3 · MeSH: D019571 (Arrhythmogenic Right Ventricular Dysplasia)

Synonyms/alternative names: arrhythmogenic right ventricular dysplasia (ARVD), arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D), arrhythmogenic cardiomyopathy (ACM), right ventricular cardiomyopathy. Left-predominant forms are termed arrhythmogenic left ventricular cardiomyopathy (ALVC).

Information source: Data are derived from aggregated disease-level resources (OMIM, Orphanet, ClinVar), disease registries (Johns Hopkins ARVC Registry, Utrecht, SHaRe, Scandinavian cohorts), and clinical/pathology studies rather than individual EHR-level extraction.

2. Etiology

Disease Causal Factors

The primary cause of ARVC is genetic, predominantly heterozygous loss-of-function variants in genes encoding the cardiac desmosome — the cell–cell adhesion junction of the intercalated disc. Desmosomal gene variants are predominant, "accounting for 67.4% of cases in cohort studies and 96.1% of pathogenic variants in ClinVar" (PMID: 42366226). Non-desmosomal genetic causes include TMEM43, PLN, FLNC, LMNA, SCN5A, DES, and RBM20 (PMID: 34970070).

Genetic Risk Factors

Causal genes: PKP2 (most common), DSP, DSG2, DSC2, JUP, TMEM43, PLN, FLNC.
Founder/high-penetrance variants: TMEM43 p.S358L (fully penetrant, Newfoundland founder); PKP2 Q59L (Finnish founder, ~20% penetrance).
Modifier effect of multiple variants: carriers of >1 mutation (~4%) have earlier VT/VF (28±12 yr) and worse outcomes (PMID: 25616645).

Environmental Risk Factors

Endurance/high-intensity exercise is the dominant modifier: "intense exercise may accelerate the phenotypic expression and the propensity to ventricular arrhythmias in patients with ACM" (PMID: 40470644).
Male sex and age are associated with worse arrhythmic outcomes, but much of the sex effect is mediated by higher exercise dose in men (PMID: 33829244).
Family history of ARVC/SCD.

Protective Factors

Exercise restriction reduces arrhythmic risk and slows phenotypic progression — the primary modifiable protective intervention.
No well-established protective genetic variants have been defined for ARVC. Non-carrier status among relatives in cascade screening is effectively protective.

Gene–Environment Interactions

The exercise–genotype interaction is the paradigmatic GxE relationship in ARVC. Mechanical load from endurance exercise stresses an already compromised desmosome, accelerating fibrofatty remodeling and arrhythmia. In a longitudinal cohort, male sex marked arrhythmia risk (OR 2.6) but lost significance after adjusting for exercise dose, indicating exercise mediates much of the sex difference (PMID: 33829244).

3. Phenotypes

ARVC symptoms typically emerge from the second to fourth decade of life (PMID: 25894016). The disease is progressive and often episodic (with arrhythmic and inflammatory "hot phase" flares).

Phenotype	Type	HPO term	Frequency / notes
Palpitations	Symptom	HP:0001962	57% in definite ARVC vs 17% non-definite (PMID: 36635648)
Syncope	Symptom	HP:0001279	35% vs 6% (PMID: 36635648)
Dyspnea	Symptom	HP:0002094	28% vs 5% (p<0.001)
Ventricular tachycardia	Clinical sign	HP:0004756	LBBB morphology; common presenting arrhythmia
Ventricular fibrillation / SCD	Clinical sign	HP:0001663 / HP:0001645	Cause of SCD in 29% of competitive athletes (PMID: 42305082)
Premature ventricular contractions	Clinical sign	HP:0006682	Very frequent (15/19 pediatric)
T-wave inversion V1–V3	Lab/ECG abnormality	HP:0012251 (abnormal T wave)	Hallmark; all pediatric pts ≥14 yr (PMID: 31375646)
Epsilon wave	Lab/ECG abnormality	—	Present only in definite group; 13/19 pediatric
Right ventricular dilatation/dysfunction	Physical manifestation	HP:0001707 / HP:0001654	Structural criterion
Heart failure	Clinical sign	HP:0001635	More common in DSP/DSG2 genotypes

In a tertiary cohort, "patients in the definite group were more symptomatic, with palpitations (57% vs. 17%), syncope (35% vs. 6%) and shortness of breath (28% vs. 5%, p < 0.001). T-wave inversion in V1-V3 and epsilon waves were observed only in the definite group" (PMID: 36635648).

Severity/progression: Variable and progressive; ranges from a "concealed phase" (arrhythmic risk without overt structure) to end-stage biventricular failure. In a Brazilian cohort, 5-year cumulative life-threatening arrhythmic event (LTAE) probability was 30% and HF-death/heart transplant 10% (PMID: 36720007).

Quality of life: Impaired by arrhythmia burden, ICD shocks, exercise restriction (particularly affecting athletes), heart-failure symptoms, and the psychological burden of SCD risk and cascade family screening. Formal EQ-5D/SF-36 disease-specific data were not identified in this investigation.

4. Genetic / Molecular Information

Causal Genes and Genotype–Phenotype Correlations

Gene	HGNC / OMIM	Frequency & phenotype
PKP2 (plakophilin-2)	HGNC:9024 / 602861	Most common (~50% in Polish cohort); truncating variants; younger diagnosis but better prognosis (higher LVEF, less HF) (PMID: 34191271)
DSG2 (desmoglein-2)	HGNC:3049 / 125671	Higher risk of transplant/HF-related death vs PKP2 (log-rank P<0.001); more LV dysfunction (PMID: 30790397)
DSP (desmoplakin)	HGNC:3052 / 125647	>4-fold LV dysfunction (40%) and HF (13%) vs PKP2; left-dominant/biventricular; hot phases (PMID: 25616645)
DSC2 (desmocollin-2)	HGNC:3036 / 125645	TCF7→TGF-β2 fibrosis pathway
JUP (plakoglobin)	HGNC:6207 / 173325	Naxos disease (recessive, cardiocutaneous)
TMEM43	HGNC:28472 / 612048	ARVD5; p.S358L fully penetrant founder; malignant
PLN, FLNC, LMNA, SCN5A, DES, RBM20	—	Non-desmosomal ACM; FLNC/LMNA/PLN high-risk for SCD

Variant Classification and Type

Variants are classified per ACMG/AMP guidelines (pathogenic, likely pathogenic, VUS). Most are truncating/loss-of-function (frameshift, nonsense, splice-site) — e.g., the PKP2 spectrum reported "5 frameshift, 2 nonsense, 2 splicing, 1 missense variants" (PMID: 34191271) — with important missense exceptions such as TMEM43 p.S358L. NGS panels in inherited heart disease clinics carry high VUS rates (~54%) (PMID: 39009076). Pathogenicity hotspots localize to critical domains (PKP2 ARM7/ARM8; DSG2 N-terminal cadherin repeats), whereas incidentally identified variants distribute like background population variation (PMID: 30985088).

Allele Frequency and Penetrance

ARVC-associated desmosomal variants are surprisingly prevalent in the general population but with reduced penetrance. In a Finnish cohort (n=6,334), "the collective prevalence of all 5 mutations... was 31 of 6,334 individuals, or 0.5%. The apparent founder mutation PKP2 Q59L is present in 0.3% of Finns and was previously shown to have an approximately 20% disease penetrance" (PMID: 21397041) — roughly 1 in 200 Finns carries a desmosomal variant.

Origin and Functional Consequences

Variants are germline. Functional consequence is predominantly loss of function / haploinsufficiency of desmosomal adhesion, with some dominant-negative effects. Endomyocardial samples of a DSG2 deletion carrier showed reduced immunoreactive signal for desmoglein-2, plakophilin-2, plakoglobin, and desmoplakin — indicating collective destabilization of the desmosomal complex (PMID: 21397041).

Modifier Genes, Epigenetics, Chromosomal

Carriage of a second variant modifies severity (PMID: 25616645). Epigenetic regulation involves tissue microRNAs: "miR-21-5p and miR-29b-3p are associated with fibrosis and extracellular matrix remodeling, whereas miR-133a-b and miR-130a are linked to cardiomyocyte integrity loss and desmosomal dysfunction" (PMID: 42353884); miR-217-5p, miR-708-5p, miR-135b link to Wnt/β-catenin and Hippo. No recurrent large-scale chromosomal abnormalities cause ARVC, though structural deletions (e.g., DSG2) occur.

5. Environmental Information

Environmental factors: No environmental toxin or radiation exposure causes ARVC. The dominant non-genetic factor is mechanical/hemodynamic load from exercise.
Lifestyle factors: Endurance and high-intensity/competitive sport is the principal lifestyle modifier — accelerating penetrance and arrhythmia; ARVC is among the most common causes of SCD in athletes (PMID: 40470644; PMID: 42305082).
Infectious agents: None cause ARVC. However, desmosomal cardiomyopathy can present as myocarditis-like "hot phases" (most commonly DSP) with troponin release mimicking acute myocarditis, involving NLRP3-inflammasome activation and anti-desmosomal/anti-intercalated-disc autoantibodies (PMID: 41448261). This aseptic intracellular inflammation is frequently misdiagnosed as viral myocarditis, particularly in children (PMID: 41255689).

6. Mechanism / Pathophysiology

Core Causal Chain

Desmosomal LOF variant (PKP2/DSP/DSG2/DSC2/JUP)
│
▼
Intercalated disc destabilization  →  ↓ Connexin-43 (Cx43) gap junctions
│                                       │
▼                                       ▼
Plakoglobin translocates to nucleus     Slowed conduction, Na-current↓
│                                (arrhythmogenic substrate)
▼
Hippo activation (Merlin/NF2→MST1/2→LATS1/2→YAP-P)
│
▼
YAP-P + phospho-β-catenin sequestered  →  ↓ canonical Wnt/β-catenin, ↓TEAD
│
▼
Pro-adipogenic + pro-fibrotic transcription  (+ DSC2→TCF7→TGF-β2 in fibroblasts)
│
▼
FIBROFATTY REPLACEMENT of myocardium  →  VT/VF, SCD, heart failure
│
   (accelerated by exercise; amplified by inflammation/autoantibodies)

Molecular Pathways

Multiple independent reviews converge on canonical and non-canonical WNT signaling, the Hippo-YAP pathway, and TGF-β signaling as the central dysregulated pathways: "these pathways include canonical and non-canonical WNT signalling, the Hippo-Yes-associated protein (YAP) pathway and transforming growth factor-β signalling" (PMID: 31028357). "Imbalance in the Wnt/β-catenin signaling and also in the crosslinked Hippo pathway leads to the transcription of proadipogenic and profibrotic genes" (PMID: 36289882). Experimentally, "altered protein constituents of intercalated discs were associated with activation of the upstream Hippo molecules" (PMID: 24276085). A distinct fibrosis arm operates through DSC2: "DSC2 deficiency upregulated transcription factor 7 (TCF7) expression, promoting its binding to TGF-β2 promoter regions to enhance TGF-β2 transcription in cardiac fibroblasts" (PMID: 42366226).

Shared Mutation-Agnostic Defect: Cx43

"The reduction in expression of the ventricular gap junction protein Cx43 (connexin-43) is a common molecular alteration underlying desmosomal junctional deficits and arrhythmias" (PMID: 41582809) — making Cx43 both a unifying mechanism and a therapeutic target.

Cellular Processes

Cardiomyocyte death (apoptosis/necrosis) → replacement fibrosis.
Fibro-adipogenic differentiation of cardiac progenitor/interstitial cells.
Microtubule detyrosination: PKP2 loss increases microtubule detyrosination and membrane stiffness, reducing sodium current; parthenolide rescues both (PMID: 42366968).
Inflammation: ACM is increasingly framed as an inflammatory cardiomyopathy — desmosomal variants activate NFκB and GSK3β signaling, promoting cytokine release and immune infiltration that may precede structural change (PMID: 42193878).

Immune / Autoantibody Involvement

"Three pathogenic ACM-IgGs activated GSK-3β upstream of p38MAPK, leading to phosphorylation and junctional loss of β-catenin. GSK-3β inhibition rescued the loss of cell cohesion" (PMID: 42219531) — establishing a pathogenic autoantibody/GSK-3β axis and a druggable node.

Single-cell / Molecular Profiling

Single-nucleus RNA-seq of left-dominant ACM hearts (5 ACM vs 4 donors) "revealed an increased proportion of fibroblasts and adipocytes in the left ventricles of LACM patients, suggesting a cellular basis for the fibrofatty remodeling observed in the disease," plus a disease-associated cardiomyocyte subpopulation (CM1) upregulating fibrosis/metabolism/stress markers (PMID: 40383406).

Suggested ontology terms: GO:0016055 (Wnt signaling), GO:0035329 (Hippo signaling), GO:0007179 (TGF-β receptor signaling), GO:0007507 (heart development), GO:0050900 (leukocyte migration); CL:0000746 (cardiac muscle cell), CL:0000057 (fibroblast), CL:0000136 (adipocyte).

7. Anatomical Structures Affected

Organ level: The heart (UBERON:0000948), primarily the right ventricle (UBERON:0002080); secondary/left ventricle (UBERON:0002084) in biventricular and left-dominant variants. Body system: cardiovascular (UBERON:0004535).

"Triangle of dysplasia": Structural remodeling primarily involves three RV regions — "the three regions ('ARVC triangle') primarily involved in ARVC structural remodeling": RV inflow/subtricuspid region, RV outflow tract, and RV apex (PMID: 33927217). Ex vivo 9.4T MRI showed high fat content in these regions: "the healthy heart exhibited twice less fat than the ARVC heart (31.9%, 28.7% and 1.3% of fat in the same regions, respectively)," histologically confirmed, with fibrosis also present in fat-poor areas (PMID: 33927217).

Tissue/cell level: Cardiac muscle tissue is replaced by fibrous (connective) and adipose tissue. Cell populations: cardiomyocytes (CL:0000746, lost), fibroblasts (CL:0000057, expanded), adipocytes (CL:0000136, expanded) (PMID: 40383406).

Subcellular level: The intercalated disc / desmosome (GO:0030057 desmosome; GO:0005912 adherens junction), gap junction (GO:0005921), nucleus (plakoglobin/YAP translocation; increased nuclear stiffness in TMEM43 carriers), and cytoskeleton/microtubules (GO:0005874).

Progression pattern: Fibrofatty replacement typically advances from epicardium/mid-myocardium toward endocardium. Left-dominant/biventricular variants involve LV lateral/posterior basal segments — "cardiac magnetic resonance showed LV late gadolinium enhancement in the LV lateral and posterior basal segments in all patients" (PMID: 33197325).

Lateralization: RV-dominant (classic), LV-dominant (ALVC), or biventricular.

8. Temporal Development

Onset: Usually adolescence to adulthood (2nd–4th decades) (PMID: 25894016); pediatric-onset ARVD occurs (mean 12±4 yr) and may be misdiagnosed as myocarditis (PMID: 31375646). Late presentation (≥50 yr) occurs in ~21% and is not benign — 65% sustained VA over 6 years (PMID: 28215569).
Onset pattern: Insidious/chronic, punctuated by acute arrhythmic or inflammatory ("hot phase") episodes.
Disease stages: (1) Concealed phase — arrhythmic risk with subtle/absent structure; (2) Overt electrical disease — symptomatic arrhythmias, ECG changes, structural RV abnormality; (3) RV failure; (4) Biventricular/end-stage failure.
Progression rate: Variable, generally slowly progressive over decades; accelerated by exercise.
Course pattern: Progressive with episodic arrhythmic/inflammatory flares.
Duration: Chronic, lifelong.
Critical periods: Adolescence/young adulthood coincident with sport participation is the critical window for SCD and for intervention (exercise restriction, ICD).

9. Inheritance and Population

Prevalence: ~1:2,000 to 1:5,000: "Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic heart disease with a prevalence of 1 : 2000 to 1 : 5000" (PMID: 40202346).
Inheritance: Predominantly autosomal dominant with reduced, age-dependent penetrance and variable expressivity. Recessive cardiocutaneous forms: Naxos disease — "mutations in the genes encoding the desmosomal proteins plakoglobin and desmoplakin have been identified as the cause of Naxos disease" (JUP; woolly hair + palmoplantar keratoderma; ~100% cardiac penetrance by adolescence — PMID: 16722579) — and Carvajal syndrome (DSP, left-dominant — PMID: 25824144).
Penetrance: Incomplete and age-dependent — e.g., PKP2 Q59L ~20% penetrance (PMID: 21397041); by contrast TMEM43 p.S358L is fully penetrant (PMID: 24598986).
Founder effects: TMEM43 p.S358L (Newfoundland; "an estimated age of 1300-1500 years for the mutation, which proves the European origin of the Newfoundland mutation" — PMID: 24598986); PKP2 Q59L (Finland).
Carrier frequency: ~0.5% collective desmosomal-variant carrier prevalence (~1 in 200) in Finland (PMID: 21397041).
Sex ratio: Male predominance. "Ventricular arrhythmia had occurred at inclusion or occurred during follow-up in 85 patients (33% of females vs. 55% of males, P = 0.002). Exercise doses were higher in males compared with females," and the sex effect lost significance after adjustment for exercise dose (PMID: 33829244); SHaRe registry showed 61% male predominance with gene-specific variation (DSP more common in females, OR 3.3) (PMID: 42159538).
Age distribution: Clinically overt from 2nd–4th decades; a substantial minority present after 50.

10. Diagnostics

Clinical Criteria

Diagnosis uses the multiparametric 1994 Task Force Criteria, revised as the 2010 modified Task Force Criteria with quantitative structural thresholds, and updated by the 2020 Padua criteria (adding left-predominant/biventricular criteria incorporating CMR late gadolinium enhancement). "The original right-dominant phenotype is traditionally diagnosed using the 2010 task force criteria, a multifactorial algorithm divided into major and minor criteria" (PMID: 38512728); "in 2010, the task force criteria were revised to include quantitative abnormalities" (PMID: 32032135). The 2010 criteria are more specific: "Of 968 patients, 220 (22.7%) fulfilled either a major or a minor 1994 TFC, and 25 (2.6%) fulfilled any of the 2010 TFC criterion" (PMID: 24996808).

Tests

ECG: T-wave inversion V1–V3, epsilon wave, QRS fragmentation, low precordial QRS voltage, signal-averaged ECG late potentials, LBBB-morphology VT.
Imaging: Echocardiography and cardiac MRI (gold standard) demonstrating RV dilatation, reduced RVEF, aneurysms/regional wall-motion abnormalities, and late gadolinium enhancement; RV angiography ("pile d'assiettes" appearance) in select cases.
Tissue: Endomyocardial biopsy showing fibrofatty replacement and reduced desmosomal immunoreactivity.
Genetic testing: Broad cardiomyopathy/arrhythmia NGS gene panels (not limited to validated ARVC genes) are recommended; WES/WGS in select cases. Panels have ~31% diagnostic yield with ~54% VUS in ICC clinics (PMID: 39009076). "Using a broad cardiomyopathy and arrhythmia gene panel in ARVC probands, rather than limiting testing to validated ARVC genes alone, is warranted" (PMID: 42389803).
Biomarkers: Circulating miR-15a-5p, miR-16-5p, miR-92a-3p differentiate high- vs low-risk patients (PMID: 40222719).
Emerging: Machine-learning models (gradient-boosted trees, AUC 0.943) enhance ARVC detection from multimodal data (PMID: 41884351).

Differential Diagnosis

Idiopathic RVOT VT, myocarditis (including hot-phase overlap), cardiac sarcoidosis, Brugada syndrome, dilated cardiomyopathy, athlete's heart, and non-desmosomal phenocopies (e.g., RIT1-related) (PMID: 41918562).

Screening

First-degree relatives undergo cascade genetic + clinical screening (ECG, echo, Holter, CMR) with genetic counseling.

11. Outcome / Prognosis

Mortality/SCD: Principal risk is SCD from ventricular arrhythmia, especially in young athletes — "ACM was the cause of SCD in 29% of athletes" in a 4-decade national juvenile registry (PMID: 42305082).
Natural history: "The 5-year cumulative probability of LTAE was 30% and HF-death/HTx was 10%" (PMID: 36720007).
Genotype-specific prognosis: PKP2 better prognosis (PMID: 34191271); DSG2/DSP higher HF/transplant risk; TMEM43 p.S358L malignant — "TMEM patients had worse composite endpoint of death or transplantation (60% vs. 0, P = 0.035; log-rank P = 0.013)" (PMID: 28960618).

Risk Stratification

The 2019 ARVC risk calculator estimates 5-year sustained-VA risk. Enhancers:

Predictor	Evidence
LV late gadolinium enhancement	"132 (34.3%) had LV LGE on cardiac magnetic resonance, with 98 (25.5%) having a high-risk pattern"; HR 1.82 for VA (PMID: 41608798)
Ringlike LV LGE	66.7% VA vs 10% no LGE; adj HR 6.91 (PMID: 38031154)
Reduced RV/LV strain (FT-CMR)	Reduced in VA patients (no incremental value over risk calculator) (PMID: 35152298)
Endocardial voltage-mapping scar	"Previous cardiac arrest or syncope (hazard ratio=3.4; 95% CI, 1.4-8.8; P=0.03)"; bipolar low-voltage HR 1.7 per 5% (PMID: 23392584)
ECG (QRS ratio ≤0.48, inferior TWI, QRS fragmentation)	Independent MACE predictors (PMID: 24792740)
Reduced RV FAC	Strongest echo predictor (HR 1.08/1% decrease) (PMID: 24515411)
Circulating miRNAs	miR-15a-5p, 16-5p, 92a-3p (PMID: 40222719)

Other established prognostic factors: prior cardiac arrest/syncope, sustained VT, RV/LV dysfunction, extent of T-wave inversion, male sex, and young age.

12. Treatment

Current therapy is palliative — it manages arrhythmias and heart failure but does not address the molecular substrate (PMID: 41301430).

Pharmacotherapy (MAXO:0000058 pharmacotherapy)

Beta-blockers — grade I for extrasystoles/VT: "Beta-blockers are recommended for patients with extrasystoles or ventricular tachycardia (grade I recommendation). If beta-blockers alone have an insufficient effect, amiodarone, flecainide or sotalol can be added (grade IIa)" (PMID: 40202346). Drug classes: beta-adrenergic antagonists, amiodarone (CHEBI:2663), sotalol, flecainide.
Heart failure therapy for ventricular dysfunction.

Interventional / Device

Catheter ablation — grade IIa for recurrent VT; palliative. Meta-analysis (24 studies, 717 patients): "acute efficacy of 89.8%, major complication of 5.2%, follow-up of 28.9 months, VT freedom of 75.3%, all-cause mortality of 1.1% and heart transplantation of 0.6%"; "epicardial ablation is associated with better long-term VT freedom" (OR 0.50 vs endocardial-only) (PMID: 33343648). DSP-ACM and TMEM43 require endo-epicardial mapping (PMID: 38206263).
ICD (MAXO implantable cardioverter defibrillator) — grade I for SCD survivors; primary-prevention decisions guided by the ARVC risk calculator; earlier ICD reasonable for PLN/FLNC/LMNA genotypes.
Heart transplantation (MAXO:0000384) — for end-stage HF or intractable arrhythmias.

Lifestyle

Exercise restriction — central, because intense exercise accelerates phenotype and arrhythmia (PMID: 40470644).

Emerging / Experimental Therapies

AAV PKP2 gene replacement (LX2020, AAVrh10): "we show minimal doses required for efficacy for AAVrh10.PKP2 (LX2020) to rescue cardiac (molecular and especially RV) deficits, arrhythmia burden and survival in PKP2 ACM mice," with no adverse events in non-human-primate safety studies (PMID: 40175378).
Mutation-agnostic AAV-Cx43 restoration: "Administration of AAV-Cx43 (adeno-associated-viral-mediated connexin-43) gene therapy alleviated the severe biventricular dilatation, contractile dysfunction, and arrhythmias, while prolonging lifespan in 2 severe desmosomal ACM mouse models" (PMID: 41582809).
AAV8-FGF21: mitigated structural change and adrenergic arrhythmias in PKP2-cKO mice (PMID: 41759869).
Small molecules: parthenolide (microtubule detyrosination — PMID: 42366968); GSK-3β inhibition (autoantibody axis — PMID: 42219531); apremilast (PDE4 inhibitor; improves cardiomyocyte cohesion via plakoglobin Ser665 phosphorylation and ERK1/2 — PMID: 41185038).
Immunomodulation during active inflammatory phases (NFκB/GSK3β/cytokine-directed) (PMID: 42193878).

Pharmacogenomics / Personalized Medicine

Genotype-guided management is emerging (e.g., earlier ICD for PLN/FLNC/LMNA; gene-specific ablation strategy) (PMID: 34970070).

13. Prevention

Primary prevention: Exercise restriction/avoidance of competitive endurance sport in carriers; ICD in high-risk individuals.
Secondary prevention: Cascade genetic and clinical screening of first-degree relatives with pre-/post-test genetic counseling; genotype-positive/phenotype-negative relatives receive periodic follow-up. "Pre-test and post-test counseling were provided to probands and cascade screening offered to relatives" (PMID: 39009076). Family screening is warranted even in gene-elusive ARVC — 17% of gene-elusive families harbored a P/LP variant in a different cardiomyopathy/arrhythmia gene (PMID: 42389803).
Tertiary prevention: ICD, ablation, and HF therapy to prevent SCD and progression.
Risk stratification: ARVC risk calculator + CMR LGE/strain + electroanatomic mapping (Section 11).
Immunization/public health: Not applicable (non-infectious, non-communicable Mendelian disease).
Counseling: Genetic counseling for family planning; preimplantation/prenatal testing possible for known familial variants.

14. Other Species / Natural Disease

Taxonomy: Homo sapiens (NCBI:txid9606); naturally occurring in Canis lupus familiaris (dog, NCBI:txid9615).
Breeds: Boxer and English bulldog dogs. "This myocardial disorder has also been described in Boxer and English bulldogs (EBs)" (PMID: 40540101). Boxer ARVC is associated with a striatin (STRN) deletion.
Comparative pathology: Canine ACM recapitulates human ECG phenotype — in 59 EBs, ACM dogs showed wider QRS and longer terminal activation, and "the TWI and ɛ wave in ACM group were respectively present in 19% and 32%," correlating with echocardiographic RV parameters (PMID: 40540101).
Orthologous genes: PKP2, DSP, DSG2, DSC2, JUP, TMEM43 are conserved across mammals; STRN in dogs.
Zoonotic potential: None (genetic disease, not transmissible).

15. Model Organisms

Model	Type	Utility / recapitulation
PKP2 cardiac-specific KO mouse (tamoxifen-inducible)	Mammalian, genetic	Recapitulates RV dysfunction, arrhythmia, microtubule detyrosination, Cx43 loss; used for AAV-PKP2/FGF21 gene therapy (PMID: 40175378; PMID: 41759869; PMID: 42366968)
Dsp / Jup mutant mice	Mammalian, genetic	Hippo activation, adipogenesis; severe biventricular desmosomal ACM for Cx43 gene therapy (PMID: 24276085; PMID: 41582809)
PKP2-knockdown HL-1 atrial myocytes	In vitro cell line	Hippo/desmosomal signaling (PMID: 24276085)
Patient hiPSC-derived cardiomyocytes (e.g., DSP mutation)	In vitro human	"Human induced pluripotent stem cells from a healthy control (hiPSC) and an ACM index patient (ACM-hiPSC) carrying a heterozygous desmoplakin (DSP) gene mutation" — cohesion/arrhythmia/drug testing (PMID: 41185038)
Non-human primate	Mammalian	AAV-PKP2 (LX2020) safety studies (PMID: 40175378)
Boxer / English bulldog dogs	Natural mammalian	Spontaneous ACM; STRN in Boxer (PMID: 40540101)

Comprehensive reviews of intercalated-disc-gene animal models confirm that murine and hiPSC models have driven mechanistic understanding and therapeutic development (PMID: 38892395; PMID: 42137277). Limitations: murine models incompletely capture the exercise-dependent, slowly progressive, and inflammatory "hot-phase" aspects of human disease and human variant heterogeneity. Resources: MGI, IMPC, Cellosaurus, Alliance of Genome Resources, OMIA.

Mechanistic Model / Interpretation

ARVC is best understood as a desmosome-initiated, signaling-amplified, mechanically-triggered fibrofatty cardiomyopathy. The upstream event is loss of desmosomal adhesion at the intercalated disc. This has two immediate consequences that map onto the two clinical hallmarks:

Electrical instability (upstream, early): reduced Cx43 gap junctions and altered sodium-channel function (partly via microtubule detyrosination) slow conduction and create a re-entrant substrate — explaining why arrhythmias and SCD can precede overt structural disease (the concealed phase). This is the mutation-agnostic arrhythmia axis and the rationale for Cx43-restoration therapy.
Structural remodeling (downstream, progressive): nuclear translocation of plakoglobin, Hippo-YAP activation, Wnt/β-catenin suppression, and TGF-β/TCF7 engagement redirect transcription toward adipogenesis and fibrosis, producing the "triangle of dysplasia" fibrofatty replacement, RV dilatation/aneurysms, and eventually biventricular failure.

Layered on top is an inflammatory amplifier (NFκB/GSK3β, NLRP3-inflammasome, anti-DSG2 autoantibodies) that produces episodic myocarditis-like hot phases, and a mechanical accelerator (endurance exercise) that increases wall stress on an adhesion-deficient myocardium — accounting for the dose-dependent exercise effect and the male predominance mediated by exercise. Genotype tunes the phenotype: PKP2 is RV-predominant and comparatively benign; DSG2/DSP skew toward LV involvement and heart failure; TMEM43 p.S358L is fully penetrant and malignant.

Evidence Base

Domain	Key PMIDs	Contribution
Genetic architecture	42366226, 34191271, 30790397, 25616645	Desmosomal predominance; PKP2/DSG2/DSP genotype–phenotype
Founder/penetrance	21397041, 24598986, 28960618	Carrier frequency, reduced penetrance, TMEM43 malignancy
Mechanism	24276085, 31028357, 36289882, 41582809, 40383406	Hippo/Wnt/TGF-β, Cx43, single-cell remodeling
Inflammation/autoimmunity	42193878, 42219531, 41448261	Inflammatory paradigm, GSK-3β autoantibody axis, hot phases
Diagnosis	38512728, 32032135, 24996808, 36635648	Task Force/Padua criteria, symptom/ECG frequencies
Risk/prognosis	41608798, 38031154, 23392584, 36720007	LGE, scar mapping, natural history
Treatment	40202346, 33343648, 40175378, 41582809	Pharmacotherapy, ablation, gene therapy
Exercise/sex	40470644, 33829244, 42305082, 42159538	Exercise modifier, sex differences
Animal/models	40540101, 38892395, 41185038	Canine disease, murine/hiPSC models

Limitations and Knowledge Gaps

Reduced penetrance and VUS burden: ~0.5% population carrier frequency with ~20% penetrance and ~54% VUS rate in panels complicate individual risk prediction and genetic counseling.
Gene-elusive disease: A substantial fraction of clinically definite ARVC lacks an identified pathogenic variant, limiting cascade screening in those families.
Risk stratification imperfection: The 2019 risk calculator underperforms in non-classical/left-dominant ACM; ringlike LGE and other markers add value but are not fully integrated.
Palliative therapeutics: No approved disease-modifying therapy currently exists; gene therapies remain preclinical/early-phase.
Causality of inflammation/autoantibodies: Whether inflammation initiates or merely amplifies disease — and whether anti-DSG2 autoantibodies are causal — remains incompletely established.
Quality-of-life data: Formal per-phenotype QoL instrument data (EQ-5D/SF-36) for ARVC were not identified in this investigation.
Model limitations: Murine models incompletely capture exercise-dependent, slowly progressive, and hot-phase human features.

Proposed Follow-up Experiments / Actions

Advance AAV gene therapies to clinical trials — track PKP2 replacement (LX2020) and mutation-agnostic Cx43 restoration; monitor ClinicalTrials.gov for first-in-human data.
Prospective validation of multimodal + ML risk models integrating CMR LGE (including ringlike pattern), FT-CMR strain, electroanatomic scar, and circulating miRNAs to improve the ARVC risk calculator, especially for left-dominant/biventricular phenotypes.
Test targeted small molecules (parthenolide, GSK-3β inhibitors, apremilast) and immunomodulation during hot phases in controlled preclinical and early-phase human studies.
Deep-phenotype gene-elusive families with WGS, structural-variant, and non-coding analyses; adopt broad cardiomyopathy/arrhythmia panels as standard.
Functionally reclassify VUS using hiPSC-CM and high-throughput assays to reduce diagnostic uncertainty.
Longitudinal exercise-dose studies to define safe activity thresholds by genotype and sex.
Collect standardized QoL/PROM data (EQ-5D, SF-36, ICD-specific measures) across ARVC registries.

References (selected PMIDs)

42366226, 42244336, 40202346, 25894016, 42305082, 40470644, 24276085, 34191271, 30790397, 25616645, 16722579, 21397041, 36635648, 36720007, 41582809, 42219531, 41185038, 40540101, 38512728, 32032135, 24996808, 41608798, 23392584, 40222719, 33927217, 33197325, 39009076, 42389803, 40383406, 42353884, 24598986, 28960618, 33343648, 33829244, 42159538, 31028357, 36289882, 40175378, 41759869, 42193878, 41448261, 41255689, 42366968, 38031154, 35152298, 24792740, 24515411, 28215569, 38206263, 41918562, 41884351, 34970070, 38892395, 42137277, 39980788, 25824144, 30985088, 41301430

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References & Deep Research

References

Deep Research

Asta Literature Retrieval: Pathophysiology and clinical mechanisms of arrhythmogenic right ventricular cardiomyopathy. Core disease mechanisms,...

Relevant Papers

[1] Special issue Heidelberg Heart II: Abstracts of oral and poster presentations

[2] Prediction of Ventricular Arrhythmias in Patients at Risk of Sudden Cardiac Death

[3] Update on Genes Associated with Arrhythmogenic Cardiomyopathy

[4] Focus on arrhythmogenic right ventricular cardiomyopathy

[5] Arrhythmogenic Cardiomyopathy: Genetic Pathology, Inflammatory Syndrome, or both?

[6] Molecular Mechanisms of Inherited Arrhythmias

[7] Arrhythmogenic cardiomyopathy: diagnosis, genetic background, and risk management

[8] Arrhythmogenic right ventricular cardiomyopathy: diverse substrate characteristics and ablation outcome.

[9] Distinct Myocardial Transcriptomic Profiles of Cardiomyopathies Stratified by the Mutant Genes

[10] Blockade of the Adenosine 2A Receptor Mitigates the Cardiomyopathy Induced by Loss of Plakophilin-2 Expression

[11] The Challenges of Diagnosis and Treatment of Arrhythmogenic Cardiomyopathy: Are We there yet?

[12] Arrhythmogenic Cardiomyopathy PKP2-Related: Clinical and Functional Characterization of a Pathogenic Variant Detected in Two Italian Families

[13] The genetic background of arrhythmogenic right ventricular cardiomyopathy

[14] Using Zebrafish Animal Model to Study the Genetic Underpinning and Mechanism of Arrhythmogenic Cardiomyopathy

[15] Contemporary genetic testing in inherited cardiac disease: tools, ethical issues, and clinical applications

[16] Experimental models of spontaneous ventricular arrhythmias and of sudden cardiac death.

[17] Extracellular vesicles in cardiomyopathies: A narrative review

[18] Familial Arrhythmogenic Cardiomyopathy: Clinical Determinants of Phenotype Discordance and the Impact of Endurance Sports

[19] Altered Electrical, Biomolecular, and Immunologic Phenotypes in a Novel Patient-Derived Stem Cell Model of Desmoglein-2 Mutant ARVC

[20] Misdiagnosed myocarditis in arrhythmogenic cardiomyopathy induced by a homozygous variant of DSG2: a case report

Notes

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC): Comprehensive Disease Research Report

1. Disease Information

2. Etiology

3. Phenotypes

4. Genetic/Molecular Information

5. Environmental Information

6. Mechanism / Pathophysiology

7. Anatomical Structures Affected

8. Temporal Development

9. Inheritance and Population

10. Diagnostics

11. Outcome/Prognosis

12. Treatment

13. Prevention

14. Other Species / Natural Disease

15. Model Organisms

Citation Summary and Confidence Notes

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) — Comprehensive Disease Characteristics Report

Summary

1. Disease Information

2. Etiology

Disease Causal Factors

Genetic Risk Factors

Environmental Risk Factors

Protective Factors

Gene–Environment Interactions

3. Phenotypes

4. Genetic / Molecular Information

Causal Genes and Genotype–Phenotype Correlations

Variant Classification and Type

Allele Frequency and Penetrance

Origin and Functional Consequences