CAPN5-related vitreoretinopathy -- most commonly termed Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy (ADNIV) -- is a rare, progressive, autosomal dominant autoinflammatory eye disease caused by heterozygous gain-of-function missense variants in CAPN5, which encodes the calcium-activated cysteine protease calpain-5. Mutant calpain-5 is hypersensitized to calcium and, in transfected-cell studies, mislocalizes from the plasma membrane to the cytosol; it is thought to aberrantly proteolyze retinal synaptic proteins, with downstream innate and CD3+ T-cell-mediated adaptive autoimmune responses, oxidative stress-associated photoreceptor degeneration, pathologic retinal/iris neovascularization, and end-stage intraocular fibrosis. The disease is notable for sequentially mimicking three common causes of blindness as it progresses through five roughly decade-long stages -- posterior uveitis, retinitis-pigmentosa-like degeneration, proliferative diabetic-retinopathy-like neovascularization, fibrotic vitreoretinopathy/tractional detachment, and phthisis bulbi. Severity correlates with the degree of protease hyperactivation conferred by the causal variant, ranging from mild, incidentally-discovered peripheral pigmentary change to a severe childhood-onset syndromic form with sensorineural hearing loss and developmental delay. No proven disease-modifying treatment exists; management is stage-based (anti-inflammatory, anti-VEGF, laser, and surgical) and often only partially effective.
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Conditions with similar clinical presentations that must be differentiated from CAPN5-Related Vitreoretinopathy:
name: CAPN5-Related Vitreoretinopathy
creation_date: "2026-07-17T00:00:00Z"
category: Mendelian
description: >-
CAPN5-related vitreoretinopathy -- most commonly termed Autosomal Dominant
Neovascular Inflammatory Vitreoretinopathy (ADNIV) -- is a rare, progressive,
autosomal dominant autoinflammatory eye disease caused by heterozygous
gain-of-function missense variants in CAPN5, which encodes the
calcium-activated cysteine protease calpain-5. Mutant calpain-5 is
hypersensitized to calcium and, in transfected-cell studies, mislocalizes
from the plasma membrane to the cytosol; it is thought to aberrantly
proteolyze retinal synaptic proteins, with downstream innate and CD3+
T-cell-mediated adaptive autoimmune responses, oxidative stress-associated
photoreceptor degeneration, pathologic retinal/iris neovascularization, and
end-stage intraocular fibrosis. The
disease is notable for sequentially mimicking three common causes of
blindness as it progresses through five roughly decade-long stages --
posterior uveitis, retinitis-pigmentosa-like degeneration, proliferative
diabetic-retinopathy-like neovascularization, fibrotic
vitreoretinopathy/tractional detachment, and phthisis bulbi. Severity
correlates with the degree of protease hyperactivation conferred by the
causal variant, ranging from mild, incidentally-discovered peripheral
pigmentary change to a severe childhood-onset syndromic form with
sensorineural hearing loss and developmental delay. No proven
disease-modifying treatment exists; management is stage-based
(anti-inflammatory, anti-VEGF, laser, and surgical) and often only partially
effective.
disease_term:
preferred_term: CAPN5-related vitreoretinopathy
term:
id: MONDO:0100450
label: CAPN5-related vitreoretinopathy
synonyms:
- Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy
- ADNIV
- Neovascular Inflammatory Vitreoretinopathy
- NIV
- CAPN5-NIV
- VRNI
parents:
- Retinal disorder
- Vitreoretinal degeneration
- Proliferative vitreoretinopathy
has_subtypes:
- name: Classic
display_name: Classic Catalytic-Domain ADNIV (R243L/L244P/K250N/G267S)
description: >-
The originally described, most extensively studied form, caused by
missense variants clustered in the catalytic protease core near the
calcium-sensitive gating loop. Onset typically in the second to third
decade, with relentless progression over roughly 40 years through the
five classic ADNIV stages to blindness.
- name: Mild Regulatory-Domain
display_name: Mild Regulatory-Domain Variant (G376S)
description: >-
A single reported variant (p.Gly376Ser) outside the catalytic domain, in
regulatory domain-III. In the single reported case -- a 19-year-old
examined at one visit -- it presented as an incidental peripheral
pigmentary degeneration with preserved visual acuity and a small area of
periphlebitis, without overt uveitis or neovascularization. Long-term
natural history is not established.
- name: Syndromic Severe
display_name: Syndromic Severe De Novo Variant (R289W)
description: >-
The most severe reported variant (p.Arg289Trp), showing the greatest
calpain hyperactivation of any tested variant. Causes childhood-onset
blindness by age five, accompanied by extraocular features not seen in
other CAPN5 variants -- progressive sensorineural hearing loss and
developmental delay.
inheritance:
- name: Autosomal dominant inheritance
inheritance_term:
preferred_term: Autosomal dominant inheritance
term:
id: HP:0000006
label: Autosomal dominant inheritance
description: >-
All reported pathogenic CAPN5 variants are heterozygous and autosomal
dominant. Founding pedigrees showed complete penetrance, though
later-identified mild, late-onset carriers (age 45 and 69) indicate
penetrance and expressivity are more variable across the broader mutation
spectrum than initially appreciated. The R289W syndromic variant arose
de novo.
evidence:
- reference: PMID:23055945
reference_title: Calpain-5 mutations cause autoimmune uveitis, retinal neovascularization, and photoreceptor degeneration.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
We identified two different missense mutations in the CAPN5 gene in
three ADNIV kindreds.
explanation: >-
Establishes the autosomal dominant, heterozygous missense basis of
ADNIV in the founding kindreds.
- reference: PMID:29472286
reference_title: A novel de novo CAPN5 mutation in a patient with inflammatory vitreoretinopathy, hearing loss, and developmental delay.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
We describe a pediatric patient with severe inflammatory
vitreoretinopathy accompanied by hearing loss and developmental delay
associated with a novel, de novo CAPN5 missense mutation
(c.865C>T, p.Arg289Trp) that shows greater hyperactivation of the
calpain protease
explanation: >-
Documents the de novo origin of the most severe reported CAPN5
variant, confirming autosomal dominant transmission is not obligatory
(new mutation can arise directly in the proband).
genetic:
- name: CAPN5
gene_term:
preferred_term: CAPN5
term:
id: hgnc:1482
label: CAPN5
relationship_type: CAUSATIVE
notes: >-
Encodes calpain-5, a 640-amino-acid calcium-activated cysteine protease
expressed in retinal photoreceptor cells. All known pathogenic variants
are heterozygous, germline, and missense -- clustering either in the
catalytic protease core near the calcium-sensitive gating loop (R243L,
L244P, K250N, G267S, R289W) or in regulatory domain-III (G376S); the
functionally tested variants are gain-of-function. Capn5 knockout mice
show no retinal phenotype, arguing against haploinsufficiency as the
disease mechanism.
variants:
- name: p.Arg243Leu (c.728G>T)
description: Catalytic core, gating loop. Classic ADNIV, onset ~20s; also reported with late-onset mild presentation at ages 45 and 69.
type: missense
clinical_significance: PATHOGENIC
- name: p.Leu244Pro (c.731T>C)
description: Catalytic core, gating loop. Classic ADNIV.
type: missense
clinical_significance: PATHOGENIC
- name: p.Lys250Asn (c.750G>T)
description: Catalytic core, gating loop. Severe uveitis, retinal neovascularization/detachment.
type: missense
clinical_significance: PATHOGENIC
- name: p.Gly267Ser (c.799G>A)
description: Catalytic domain (exon 6). Severe, congenital nystagmus, early vitreoretinopathy.
type: missense
clinical_significance: PATHOGENIC
- name: p.Gly376Ser (c.1126G>A)
description: Regulatory domain-III. Mild, incidental, near-normal vision at age 19.
type: missense
clinical_significance: PATHOGENIC
- name: p.Arg289Trp (c.865C>T)
description: Catalytic domain, de novo. Most severe/syndromic variant -- childhood blindness, hearing loss, developmental delay.
type: missense
clinical_significance: PATHOGENIC
evidence:
- reference: PMID:23055945
reference_title: Calpain-5 mutations cause autoimmune uveitis, retinal neovascularization, and photoreceptor degeneration.
supports: SUPPORT
evidence_source: IN_VITRO
snippet: >-
CAPN5 encodes calpain-5, a calcium-activated cysteine protease that is
expressed in retinal photoreceptor cells. Both mutations cause
mislocalization from the cell membrane to the cytosol, and structural
modeling reveals that both mutations lie within a calcium-sensitive
domain near the active site.
explanation: >-
Establishes CAPN5 as the causal gene. The mislocalization was
demonstrated in transfected HEK293T cells (with structural modeling of
the calcium-sensitive domain), not in patient photoreceptors.
- reference: PMID:25856303
reference_title: Structural modeling of a novel CAPN5 mutation that causes uveitis and neovascular retinal detachment.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Two daughters of an affected mother demonstrated symptoms of stage III
ADNIV, with posterior uveitis, cystoid macular edema, intraocular
fibrosis, retinal neovascularization, retinal degeneration, and
cataract. The women also harbored a novel guanine to thymine (c.750G>T,
p.Lys250Asn) missense mutation in exon 6 of CAPN5
explanation: >-
Documents the K250N (c.750G>T) gating-loop variant and its severe
uveitic/neovascular phenotype in an affected kindred.
- reference: PMID:29040051
reference_title: Two Novel CAPN5 Variants Associated with Mild and Severe Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy Phenotypes.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Next-generation sequencing identified that the patient was
heterozygous for CAPN5 c.799G>A, p.(Gly267Ser).
explanation: >-
Documents the severe catalytic-domain G267S variant and its
genotype-phenotype correlation with disease severity.
- reference: PMID:29040051
reference_title: Two Novel CAPN5 Variants Associated with Mild and Severe Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy Phenotypes.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The CAPN5 variant c.1126G>A, p.(Gly376Ser) was identified in this
patient. This variant is present at an allele frequency of 0.017% in
the South Asian population within the Exome Aggregate Consortium
(ExAC) database13.
explanation: >-
Documents the mild regulatory-domain G376S variant, the first
reported outside the catalytic domain.
pathophysiology:
- name: CAPN5 Gain-of-Function Protease Hyperactivation
description: >-
Heterozygous missense mutations near the calcium-sensitive gating loop of
the calpain-5 catalytic core increase calcium sensitivity and catalytic
activity of the enzyme; in transfected HEK293T cells the founding mutant
proteins localize to the cytoplasm rather than near the cell surface,
suggesting the mutations may alter a membrane-binding property of
calpain-5. The regulatory domain-III variant G376S has not been
functionally assayed and is only hypothesized to have a milder effect on
protein function. Capn5 knockout mice show no retinal phenotype,
indicating the disease mechanism is gain-of-function rather than
haploinsufficiency.
role: trigger
locations:
- preferred_term: retina
term:
id: UBERON:0000966
label: retina
cell_types:
- preferred_term: Photoreceptor Cell
term:
id: CL:0000210
label: photoreceptor cell
molecular_functions:
- preferred_term: Calcium-Dependent Cysteine-Type Endopeptidase Activity
term:
id: GO:0004198
label: calcium-dependent cysteine-type endopeptidase activity
modifier: INCREASED
genetic_context:
gene:
preferred_term: CAPN5
term:
id: hgnc:1482
label: CAPN5
allele_type: missense
variant_origin: GERMLINE
zygosity: HETEROZYGOUS
functional_impact_category: GAIN_OF_FUNCTION
description: >-
Heterozygous missense variants in the CAPN5 protease domain. Recorded as
GAIN_OF_FUNCTION rather than haploinsufficiency: the variants hyperactivate the
calpain-5 protease, and the inflammatory and neovascular phenotype is not seen
with CAPN5 deletion.
evidence:
- reference: PMID:23055945
reference_title: Calpain-5 mutations cause autoimmune uveitis, retinal neovascularization, and photoreceptor degeneration.
supports: SUPPORT
evidence_source: IN_VITRO
snippet: >-
Both mutations cause mislocalization from the cell membrane to the
cytosol, and structural modeling reveals that both mutations lie
within a calcium-sensitive domain near the active site.
explanation: >-
Shows mislocalization of the founding ADNIV mutants in transfected
HEK293T cells, which the source interprets as suggesting the mutations
may alter a membrane-binding property of the protein.
- reference: PMID:23055945
reference_title: Calpain-5 mutations cause autoimmune uveitis, retinal neovascularization, and photoreceptor degeneration.
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
Capn5 knockout mice have no observable phenotype
explanation: >-
Knockout-mouse evidence arguing against haploinsufficiency and
supporting a gain-of-function mechanism for ADNIV.
- reference: PMID:23055945
reference_title: "Calpain-5 mutations cause autoimmune uveitis, retinal neovascularization, and photoreceptor degeneration."
supports: SUPPORT
evidence_source: OTHER
snippet: "Although these mutations could cause disease through haploinsufficiency, it seems more likely that they result in a gain of function of calpain-5 that causes harm to the photoreceptor cells."
explanation: >-
The gene-discovery paper weighs haploinsufficiency against gain of function and
favours gain of function, the category recorded here. Graded OTHER because the
sentence is the authors' own reasoning in discussion rather than a reported
clinical finding; the same sentence carries that grade on the entry's
refuted_haploinsufficiency_model hypothesis.
downstream:
- target: Aberrant Photoreceptor Synaptic Proteolysis
- name: Aberrant Photoreceptor Synaptic Proteolysis
description: >-
Hyperactive, mislocalized calpain-5 is hypothesized to aberrantly
proteolyze substrates at the retinal ribbon synapse in the retina's
naturally high-calcium phototransduction environment; the specific
protein substrates of calpain-5 have not been identified. Vitreous
proteomics of CAPN5-NIV patients shows early loss of synaptic proteins
including neurexin-2, glutamate receptor 4 (a receptor expressed in rod
bipolar cells), and neurofascin. The proteomic analysis could not
differentiate which retinal cells are affected by these losses, which
may contribute to the synaptic signaling defect -- reduced ERG b-wave
amplitude -- seen in early disease.
role: central_effector
locations:
- preferred_term: retina
term:
id: UBERON:0000966
label: retina
cell_types:
- preferred_term: Photoreceptor Cell
term:
id: CL:0000210
label: photoreceptor cell
biological_processes:
- preferred_term: Proteolysis
term:
id: GO:0006508
label: proteolysis
modifier: INCREASED
evidence:
- reference: PMID:31110225
reference_title: Proteomic insight into the pathogenesis of CAPN5-vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
we observed a significant fraction of proteins localized to the
synapse in controls that decreased in CAPN5-NIV vitreous. Among these
proteins were: neurexin-2 (NRXN2), glutamate receptor 4 (GluR4),
neurofascin (NFASC)
explanation: >-
Vitreous proteomics documents decreased synaptic proteins in
CAPN5-NIV patients, consistent with aberrant calpain-mediated
synaptic proteolysis, though the study could not attribute the losses
to a specific retinal cell type.
- reference: PMID:31110225
reference_title: Proteomic insight into the pathogenesis of CAPN5-vitreoretinopathy.
supports: NO_EVIDENCE
evidence_source: HUMAN_CLINICAL
snippet: >-
However, our proteomic analysis could not differentiate which retinal
cells are affected by loss of these proteins in CAPN5-NIV
explanation: >-
Explicit caveat from the same proteomic study: the retinal cell
type(s) losing these synaptic proteins could not be determined, so a
photoreceptor-specific attribution is not established. Recorded as
NO_EVIDENCE because the sentence carries no evidence bearing on
whether the proteolysis is photoreceptor-specific; it bounds
the node's photoreceptor cell-type binding rather than asserting the
node's proteolysis claim.
- reference: PMID:25994508
reference_title: "CAPN5 mutation in hereditary uveitis: the R243L mutation increases calpain catalytic activity and triggers intraocular inflammation in a mouse model."
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
Electroretinography showed mutant mouse eyes had a selective loss of
the b-wave indicating an inner-retina signaling defect.
explanation: >-
Mouse model evidence linking mutant CAPN5 expression to the reduced
ERG b-wave, the earliest clinical/electrophysiological correlate of
synaptic dysfunction.
downstream:
- target: Innate and Adaptive Autoimmune Uveitis
- name: Innate and Adaptive Autoimmune Uveitis
description: >-
Aberrant proteolysis and the resulting cellular stress may trigger
local innate immune activation (Toll-like receptor pathway genes,
chemokines, cytokines, complement components) accompanied by dense CD3+
T-lymphocyte infiltration of the uvea, vitreous, and retina, driving
chronic autoimmune uveitis; how the innate and adaptive arms interact
in CAPN5-NIV pathogenesis remains under investigation. Vitreous
TNF-alpha levels are normal, explaining why patients fail conventional
anti-TNF immunosuppression (e.g. infliximab).
role: central_effector
locations:
- preferred_term: uvea
term:
id: UBERON:0001768
label: uvea
- preferred_term: vitreous body
term:
id: UBERON:0001798
label: vitreous body
cell_types:
- preferred_term: T Cell
term:
id: CL:0000084
label: T cell
biological_processes:
- preferred_term: Innate Immune Response
term:
id: GO:0045087
label: innate immune response
modifier: INCREASED
- preferred_term: Adaptive Immune Response
term:
id: GO:0002250
label: adaptive immune response
modifier: INCREASED
evidence:
- reference: PMID:25994508
reference_title: "CAPN5 mutation in hereditary uveitis: the R243L mutation increases calpain catalytic activity and triggers intraocular inflammation in a mouse model."
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
Analysis of gene expression changes in the hCAPN5(R243L) mouse retina
showed upregulation of several markers, including members of the
Toll-like receptor pathway, chemokines and cytokines, indicative of
both an innate and adaptive immune response.
explanation: >-
Mouse model transcriptomic evidence for innate and adaptive immune
pathway activation downstream of mutant CAPN5 expression.
- reference: PMID:23861576
reference_title: Lymphocyte infiltration in CAPN5 autosomal dominant neovascular inflammatory vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Chronic inflammatory CD3-positive cell infiltrates were identified
throughout the uvea, vitreous and retina, consistent with chronic
uveitis.
explanation: >-
Human histopathology directly demonstrating CD3+ T-cell infiltration
of the uvea, vitreous, and retina in an enucleated ADNIV eye.
- reference: PMID:31110225
reference_title: Proteomic insight into the pathogenesis of CAPN5-vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
This analysis showed that TNF-α levels were normal, explaining why
infliximab therapy failed in these patients
explanation: >-
Documents normal vitreous TNF-alpha in CAPN5-NIV patient samples,
supporting the node's claim that anti-TNF immunosuppression
(infliximab) fails in these patients.
downstream:
- target: Oxidative Stress-Driven Photoreceptor Degeneration
- target: Opticin Loss and Pathologic Retinal Neovascularization
- name: Oxidative Stress-Driven Photoreceptor Degeneration
description: >-
Chronic inflammation is accompanied by loss of vitreous antioxidant
defenses (superoxide dismutase, peroxiredoxins, catalase, clusterin),
indicating reduced defense against oxidative stress that may leave
photoreceptors vulnerable to oxidative injury. A
retinitis-pigmentosa-like pigmentary photoreceptor degeneration (ADNIV
Stage II) follows, distinguished from classic RP by pigment clumping
rather than bone-spicule pigmentation.
role: central_effector
conforms_to: "photoreceptor_degeneration#Photoreceptor Metabolic and Oxidative Stress"
locations:
- preferred_term: retina
term:
id: UBERON:0000966
label: retina
cell_types:
- preferred_term: Photoreceptor Cell
term:
id: CL:0000210
label: photoreceptor cell
biological_processes:
- preferred_term: Response to Oxidative Stress
term:
id: GO:0006979
label: response to oxidative stress
modifier: INCREASED
evidence:
- reference: PMID:31110225
reference_title: Proteomic insight into the pathogenesis of CAPN5-vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
There were proteins with known antioxidant activity present in
controls that were absent in CAPN5-NIV vitreous: superoxide dismutase
(SOD1 and SOD3), peroxiredoxin (PRDX2 and PRDX6), catalase (CAT),
clusterin, and glutathione peroxidase 3 (GPX3).
explanation: >-
Vitreous proteomics documents loss of multiple antioxidant defense
proteins, supporting oxidative stress as a driver of photoreceptor
degeneration.
downstream:
- target: Fibrotic Proliferative Vitreoretinopathy and Progressive Blindness
- name: Opticin Loss and Pathologic Retinal Neovascularization
description: >-
Downregulation of the anti-angiogenic vitreous matrix protein opticin
may contribute, together with elevated vascular endothelial growth
factor (VEGF), to pathologic retinal and iris neovascularization
mimicking proliferative diabetic retinopathy (ADNIV Stage III).
Anti-VEGF therapy (bevacizumab) has been repositioned to suppress this
neovascularization.
role: central_effector
locations:
- preferred_term: retina
term:
id: UBERON:0000966
label: retina
cell_types:
- preferred_term: Retinal Blood Vessel Endothelial Cell
term:
id: CL:0002585
label: retinal blood vessel endothelial cell
biological_processes:
- preferred_term: Angiogenesis
term:
id: GO:0001525
label: angiogenesis
modifier: INCREASED
evidence:
- reference: PMID:31110225
reference_title: Proteomic insight into the pathogenesis of CAPN5-vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Among the significantly-downregulated proteins were several proteins
involved in retinal function: retinoschisin (RS1), and opticin (OPTC)
explanation: >-
Documents opticin among the significantly downregulated proteins in
CAPN5-NIV vitreous; the paper proposes that opticin downregulation
may contribute to the increased retinal neovascularization seen in
these patients.
- reference: PMID:31110225
reference_title: Proteomic insight into the pathogenesis of CAPN5-vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
It was further revealed that the CAPN5-NIV vitreous contained
abundant levels of vascular endothelial growth factor (VEGF), T-cell
proliferative markers, and interleukin-6 (IL-6).
explanation: >-
Documents elevated vitreous VEGF as the angiogenic driver of
CAPN5-NIV retinal/iris neovascularization.
downstream:
- target: Fibrotic Proliferative Vitreoretinopathy and Progressive Blindness
- name: Fibrotic Proliferative Vitreoretinopathy and Progressive Blindness
description: >-
Downregulation of the vitreous structural proteoglycan versican may
disrupt normal vitreous architecture, contributing to intraocular
fibrosis, epiretinal membrane formation, and tractional retinal
detachment (ADNIV Stage IV). Structural damage is generally
irreversible; the disease culminates in phthisis bulbi and complete
blindness (Stage V) despite corticosteroid control of active
inflammation.
role: outcome
conforms_to: "fibrotic_response#Architectural Distortion and Organ Dysfunction"
locations:
- preferred_term: vitreous body
term:
id: UBERON:0001798
label: vitreous body
- preferred_term: retina
term:
id: UBERON:0000966
label: retina
evidence:
- reference: PMID:31110225
reference_title: Proteomic insight into the pathogenesis of CAPN5-vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Among the downregulated pro-teins was versican (VCAN/CSPG2). Versican
is a chondroitin sulfate proteoglycan involved in maintaining the
physiologic structure of the vitreous.
explanation: >-
Documents versican among the downregulated proteins in CAPN5-NIV
vitreous and its role in maintaining vitreous structure. (The quoted
text preserves the source PDF's line-break hyphenation in
"pro-teins".)
- reference: PMID:23861576
reference_title: Lymphocyte infiltration in CAPN5 autosomal dominant neovascular inflammatory vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The eye showed exudative retinal detachment and neovascularization,
intraocular fibrosis, and features of phthisis bulbi.
explanation: >-
Human histopathology of a Stage V ADNIV eye documenting the terminal
fibrotic/phthisical outcome.
mechanistic_hypotheses:
- hypothesis_group_id: canonical_gain_of_function_model
hypothesis_label: Canonical Gain-of-Function Protease Hyperactivation Model
status: CANONICAL
description: >-
ADNIV-causing CAPN5 variants act through gain-of-function protease
hyperactivation and mislocalization rather than loss of normal calpain-5
function. This is the predominant model, supported by Capn5 knockout mice
lacking a retinal phenotype and by direct biochemical demonstration of
increased calcium sensitivity and mislocalization in all tested disease
variants.
evidence:
- reference: PMID:23055945
reference_title: "Calpain-5 mutations cause autoimmune uveitis, retinal neovascularization, and photoreceptor degeneration."
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
Capn5 knockout mice have no observable phenotype
explanation: >-
Knockout mice lacking a phenotype argues against haploinsufficiency,
supporting the gain-of-function model.
- hypothesis_group_id: refuted_haploinsufficiency_model
hypothesis_label: Refuted Haploinsufficiency Model
status: DEPRECATED
description: >-
An initially plausible alternative hypothesis was that ADNIV variants
act through simple loss of calpain-5 function (haploinsufficiency),
analogous to CAPN3 loss-of-function causing limb-girdle muscular
dystrophy. The founding paper left the question open but judged gain of
function more likely; the model is disfavored by the normal phenotype of
Capn5-null mice and by subsequent in vitro data showing tested disease
variants are catalytically hyperactive, not hypoactive.
evidence:
- reference: PMID:23055945
reference_title: "Calpain-5 mutations cause autoimmune uveitis, retinal neovascularization, and photoreceptor degeneration."
supports: REFUTE
evidence_source: OTHER
snippet: >-
Although these mutations could cause disease through
haploinsufficiency, it seems more likely that they result in a gain
of function of calpain-5 that causes harm to the photoreceptor cells.
explanation: >-
The founding paper's own discussion weighs haploinsufficiency against
gain of function and judges gain of function more likely; this is
authors' reasoning rather than primary clinical data, and the paper
does not definitively exclude a loss-of-function contribution.
- reference: PMID:25994508
reference_title: "CAPN5 mutation in hereditary uveitis: the R243L mutation increases calpain catalytic activity and triggers intraocular inflammation in a mouse model."
supports: REFUTE
evidence_source: IN_VITRO
snippet: >-
In in vitro activity assays, the mutation increased calpain protease
activity and made it far more active at low concentrations of calcium.
explanation: >-
Direct biochemical demonstration that the R243L disease variant is
catalytically hyperactive, not hypoactive, arguing against the
haploinsufficiency model.
phenotypes:
- category: Ophthalmologic
name: Non-infectious posterior uveitis
subtype: Classic
description: >-
Stage I disease presents as non-infectious posterior uveitis with
vitreous cells and reduced ERG b-wave amplitude, clinically
indistinguishable from idiopathic uveitis.
phenotype_term:
preferred_term: Uveitis
term:
id: HP:0000554
label: Uveitis
temporality: CHRONIC
evidence:
- reference: PMID:23055945
reference_title: Calpain-5 mutations cause autoimmune uveitis, retinal neovascularization, and photoreceptor degeneration.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV)
is an autoimmune condition of the eye that sequentially mimics
uveitis, retinitis pigmentosa, and proliferative diabetic retinopathy
as it progresses to complete blindness.
explanation: >-
Establishes uveitis as the earliest clinical presentation in the
canonical staged disease course.
- category: Ophthalmologic
name: Abnormal electroretinogram
subtype: Classic
description: >-
Reduced or absent ERG b-wave is often the earliest objective
abnormality, reflecting an inner-retina synaptic signaling defect
attributed to aberrant calpain-5 proteolysis.
phenotype_term:
preferred_term: Abnormal electroretinogram
term:
id: HP:0000512
label: Abnormal electroretinogram
temporality: CHRONIC
evidence:
- reference: PMID:23055945
reference_title: Calpain-5 mutations cause autoimmune uveitis, retinal neovascularization, and photoreceptor degeneration.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
In Stage I disease, there are mild cells (white dots) in the vitreous
(orange) and a reduced b-wave on electroretinography (ERG).
explanation: >-
Human staging description documenting reduced ERG b-wave as an early
(Stage I) finding in ADNIV patients.
- reference: PMID:32274441
reference_title: Phenotypic variance in Calpain-5 retinal degeneration.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Full-field scotopic 3.0 and 10.0 flash ERG demonstrated normal to
mildly reduced a-wave amplitudes (approximately 5–20% of normal
controls OU) but attenuation of the b-wave to 60–80% of normal in OU
in the patient
explanation: >-
Quantitative human ERG in a CAPN5 p.R243L patient showing selective
b-wave attenuation with relatively preserved a-waves.
- reference: PMID:25994508
reference_title: "CAPN5 mutation in hereditary uveitis: the R243L mutation increases calpain catalytic activity and triggers intraocular inflammation in a mouse model."
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
Electroretinography showed mutant mouse eyes had a selective loss of
the b-wave indicating an inner-retina signaling defect.
explanation: >-
Corroborating mouse model evidence for the ERG b-wave loss observed
in human patients.
- category: Ophthalmologic
name: Pigmentary retinal degeneration
subtype: Classic
description: >-
Stage II disease shows a retinitis-pigmentosa-like pigmentary
photoreceptor degeneration, distinguished from classic RP by clumped
rather than bone-spicule pigmentation.
phenotype_term:
preferred_term: Pigmentary retinopathy
term:
id: HP:0000580
label: Pigmentary retinopathy
temporality: CHRONIC
clinical_course: PROGRESSIVE
evidence:
- reference: PMID:32274441
reference_title: Phenotypic variance in Calpain-5 retinal degeneration.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Two subjects with this CAPN5 variant only showed mild peripheral
retinal pigmentary degeneration and loss of the ERG b-wave at age 45
and 69, respectively, without signs of uveitis or neovascularization.
explanation: >-
Documents pigmentary retinal degeneration as a core, sometimes
isolated, CAPN5-related phenotype.
- category: Ophthalmologic
name: Retinal and iris neovascularization
subtype: Classic
description: >-
Stage III disease shows retinal and iris neovascularization resembling
proliferative diabetic retinopathy, driven by opticin loss and elevated
vitreous VEGF.
phenotype_term:
preferred_term: Retinal neovascularization
term:
id: HP:0030666
label: Retinal neovascularization
temporality: CHRONIC
clinical_course: PROGRESSIVE
evidence:
- reference: PMID:31110225
reference_title: Proteomic insight into the pathogenesis of CAPN5-vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
It was further revealed that the CAPN5-NIV vitreous contained
abundant levels of vascular endothelial growth factor (VEGF), T-cell
proliferative markers, and interleukin-6 (IL-6).
explanation: >-
Elevated vitreous VEGF documents the angiogenic driver of the Stage
III neovascular phenotype.
- category: Ophthalmologic
name: Tractional retinal detachment
subtype: Classic
description: >-
Stage IV disease shows intraocular fibrosis, epiretinal membrane
formation, and tractional retinal detachment as versican loss disrupts
normal vitreous architecture.
phenotype_term:
preferred_term: Retinal detachment
term:
id: HP:0000541
label: Retinal detachment
temporality: CHRONIC
clinical_course: PROGRESSIVE
evidence:
- reference: PMID:23861576
reference_title: Lymphocyte infiltration in CAPN5 autosomal dominant neovascular inflammatory vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The eye showed exudative retinal detachment and neovascularization,
intraocular fibrosis, and features of phthisis bulbi.
explanation: >-
Human histopathology directly documenting retinal detachment and
intraocular fibrosis in advanced ADNIV.
- category: Ophthalmologic
name: Phthisis bulbi
subtype: Classic
description: >-
Terminal Stage V disease: atrophy and degeneration of the blind eye,
with complete, generally irreversible vision loss.
phenotype_term:
preferred_term: Phthisis bulbi
term:
id: HP:0000667
label: Phthisis bulbi
temporality: CHRONIC
clinical_course: PROGRESSIVE
evidence:
- reference: PMID:23861576
reference_title: Lymphocyte infiltration in CAPN5 autosomal dominant neovascular inflammatory vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The eye showed exudative retinal detachment and neovascularization,
intraocular fibrosis, and features of phthisis bulbi.
explanation: >-
Documents phthisis bulbi as the terminal outcome in an enucleated
Stage V ADNIV eye specimen.
- category: Audiologic
name: Progressive sensorineural hearing loss
subtype: Syndromic Severe
description: >-
Reported only with the most severe (R289W) variant: progressive
sensorineural hearing loss unresponsive to immunosuppression,
accompanying the ocular disease.
phenotype_term:
preferred_term: Sensorineural hearing impairment
term:
id: HP:0000407
label: Sensorineural hearing impairment
temporality: CHRONIC
clinical_course: PROGRESSIVE
evidence:
- reference: PMID:29472286
reference_title: A novel de novo CAPN5 mutation in a patient with inflammatory vitreoretinopathy, hearing loss, and developmental delay.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
We describe a pediatric patient with severe inflammatory
vitreoretinopathy accompanied by hearing loss and developmental delay
associated with a novel, de novo CAPN5 missense mutation
(c.865C>T, p.Arg289Trp)
explanation: >-
Documents sensorineural hearing loss as an extraocular feature unique
to the most severe (R289W) CAPN5 variant.
- category: Neurologic
name: Global developmental delay
subtype: Syndromic Severe
description: >-
Reported only with the R289W variant, alongside hearing loss and
childhood-onset blindness, indicating a genotype-phenotype correlation
between mutation severity and syndromic extraocular involvement.
phenotype_term:
preferred_term: Global developmental delay
term:
id: HP:0001263
label: Global developmental delay
evidence:
- reference: PMID:29472286
reference_title: A novel de novo CAPN5 mutation in a patient with inflammatory vitreoretinopathy, hearing loss, and developmental delay.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
We describe a pediatric patient with severe inflammatory
vitreoretinopathy accompanied by hearing loss and developmental delay
associated with a novel, de novo CAPN5 missense mutation
(c.865C>T, p.Arg289Trp)
explanation: >-
Documents global developmental delay as part of the syndromic R289W
phenotype.
prevalence:
- population: Reported kindreds worldwide
measure_type: CASES_IN_LITERATURE
prevalence_class: ULTRA_RARE
notes: >-
ADNIV is extremely rare; the founding report described three kindreds,
and fewer than a dozen distinct pathogenic-variant families have been
published to date worldwide. No population-based prevalence or incidence
study (Orphanet/GBD) was identified. The variants reported in the
founding kindreds were absent from dbSNP and 1000 Genomes, but
later-reported variants appear at low allele frequencies in population
reference databases: G267S at 0.023% (European) and 0.047% (Finnish) in
ExAC, and G376S at 0.017% (South Asian) in ExAC -- the latter equating
to a carrier rate of about 1 in 6,000 in that population, most of whom
would be expected to have subclinical or differently diagnosed disease.
evidence:
- reference: PMID:23055945
reference_title: Calpain-5 mutations cause autoimmune uveitis, retinal neovascularization, and photoreceptor degeneration.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
We identified two different missense mutations in the CAPN5 gene in
three ADNIV kindreds.
explanation: >-
Establishes the extreme rarity of ADNIV via the founding kindred
count.
- reference: PMID:23055945
reference_title: Calpain-5 mutations cause autoimmune uveitis, retinal neovascularization, and photoreceptor degeneration.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
None of the three variants were listed in the dbSNP or 1000 Genome
databases.
explanation: >-
Documents that the variants in the founding kindreds were absent from
population reference databases; this absence claim is specific to
those founding variants.
- reference: PMID:29040051
reference_title: Two Novel CAPN5 Variants Associated with Mild and Severe Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy Phenotypes.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
This variant has been identified at an allele frequency of 0.023% and
0.047% in European and Finnish populations respectively within the
Exome Aggregate Consortium (ExAC) database
explanation: >-
Documents ExAC population allele frequencies for the G267S variant,
showing later-reported pathogenic variants are present in population
reference databases.
- reference: PMID:29040051
reference_title: Two Novel CAPN5 Variants Associated with Mild and Severe Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy Phenotypes.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The prevalence of 0.017% on the ExAc database would equate to a
carrier rate of about 1 in 6,000 in the South Asian population, but it
is likely that many of these patients would have subclinical disease,
or other broad clinical diagnoses
explanation: >-
Source of the G376S carrier-rate estimate and its subclinical-disease
caveat quoted in the notes.
diagnosis:
- name: CAPN5 single-gene sequencing
description: >-
Single-gene CAPN5 sequencing (Sanger or targeted NGS), or inclusion of
CAPN5 in inherited-retinal-dystrophy gene panels, is the recommended
diagnostic approach in patients with atypical uveitis, atypical
retinitis pigmentosa, or a family history of progressive
vitreoretinopathy. Electroretinography (reduced/absent b-wave amplitude)
is the characteristic early functional finding supporting the diagnosis.
diagnosis_term:
preferred_term: genetic testing
term:
id: NCIT:C15709
label: Genetic Testing
results: "Identification of a heterozygous pathogenic CAPN5 missense variant confirms the diagnosis."
evidence:
- reference: PMID:29040051
reference_title: Two Novel CAPN5 Variants Associated with Mild and Severe Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy Phenotypes.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Next-generation sequencing identified that the patient was
heterozygous for CAPN5 c.799G>A, p.(Gly267Ser).
explanation: >-
Demonstrates NGS-based CAPN5 sequencing as the diagnostic method that
identified a novel pathogenic variant.
differential_diagnoses:
- name: Idiopathic non-infectious posterior uveitis
distinguishing_features:
- Family history of progressive vitreoretinopathy and CAPN5 genetic testing distinguish ADNIV from truly idiopathic uveitis
- ADNIV additionally shows reduced ERG b-wave at presentation, not typical of isolated idiopathic uveitis
evidence:
- reference: PMID:23055945
reference_title: Calpain-5 mutations cause autoimmune uveitis, retinal neovascularization, and photoreceptor degeneration.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV)
is an autoimmune condition of the eye that sequentially mimics
uveitis, retinitis pigmentosa, and proliferative diabetic retinopathy
as it progresses to complete blindness.
explanation: >-
States explicitly that ADNIV mimics idiopathic uveitis as its earliest
presentation.
- name: Autosomal dominant retinitis pigmentosa
distinguishing_features:
- ADNIV shows pigment clumps rather than the classic bone-spicule pigmentation of typical retinitis pigmentosa
- A preceding history of uveitis and subsequent neovascularization/fibrosis stages are not features of isolated ADRP
evidence:
- reference: PMID:32274441
reference_title: Phenotypic variance in Calpain-5 retinal degeneration.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Patients with pigmentary retinal dystrophy may consider CAPN5 gene
testing.
explanation: >-
Recommends CAPN5 testing in patients presenting with a pigmentary
retinal dystrophy phenotype that could otherwise be mistaken for ADRP.
- name: Familial exudative vitreoretinopathy
distinguishing_features:
- FEVR lacks the prominent chronic autoimmune uveitis and CD3+ T-cell infiltration characteristic of ADNIV
- A FEVR-like phenotype with negative genetic testing for the typical FEVR genes should prompt CAPN5 testing
evidence:
- reference: PMID:23861576
reference_title: Lymphocyte infiltration in CAPN5 autosomal dominant neovascular inflammatory vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Chronic inflammatory CD3-positive cell infiltrates were identified
throughout the uvea, vitreous and retina, consistent with chronic
uveitis.
explanation: >-
Documents the CD3+ T-cell-mediated chronic uveitis that distinguishes
ADNIV from the non-inflammatory vascular pathology of FEVR.
- reference: PMID:29040051
reference_title: Two Novel CAPN5 Variants Associated with Mild and Severe Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy Phenotypes.
supports: SUPPORT
evidence_source: OTHER
snippet: >-
This may also include patients who have a phenotype of familial
exudative vitreoretinopathy (FEVR) in which genetic testing for the
typical FEVR genes is negative.
explanation: >-
Authors' recommendation that FEVR-phenotype patients negative for the
typical FEVR genes be considered for CAPN5 testing, supporting FEVR
as a differential diagnosis.
treatments:
- name: Corticosteroid Therapy
description: >-
Corticosteroids are used to control active intraocular inflammation;
intraocular steroids suppress inflammatory cells and neovascularization
but not the retinal fibrosis or degenerative component of disease.
treatment_term:
preferred_term: corticosteroid agent therapy
term:
id: NCIT:C15370
label: Steroid Therapy
evidence:
- reference: PMID:23861576
reference_title: Lymphocyte infiltration in CAPN5 autosomal dominant neovascular inflammatory vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Mutations in CAPN5 trigger autoimmune uveitis characterized by
inflammatory T-cells and severe neovascularization.
explanation: >-
Establishes the T-cell-mediated autoimmune uveitis that
corticosteroid therapy targets.
- reference: PMID:29040051
reference_title: Two Novel CAPN5 Variants Associated with Mild and Severe Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy Phenotypes.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
This is supported by studies which found that intraocular steroids
suppress inflammatory cells and neovascularisation but not retinal
fibrosis or degeneration in ADNIV patients
explanation: >-
Directly supports the incomplete steroid response: inflammation and
neovascularization are suppressed but the fibrotic/degenerative
component is not.
- name: Anti-VEGF Therapy (Bevacizumab)
description: >-
Intravitreal bevacizumab, an anti-VEGF monoclonal antibody, was
repositioned based on proteomic evidence of elevated vitreous VEGF and
successfully mitigated neovascularization in CAPN5-NIV patients.
treatment_term:
preferred_term: Pharmacotherapy
term:
id: NCIT:C15986
label: Pharmacotherapy
therapeutic_agent:
- preferred_term: bevacizumab
term:
id: NCIT:C2039
label: Bevacizumab
evidence:
- reference: PMID:31110225
reference_title: Proteomic insight into the pathogenesis of CAPN5-vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Based on this, we repositioned bevacizumab (anti-VEGF monoclonal
antibody), intravitreal methotrexate (T-cell inhibi-tor), and
tocilizumab (anti-IL-6 monoclonal antibody) and successfully mitigated
neovascularization, inflamma-tory cell infiltration, and persistent
fibrosis in these patients
explanation: >-
Documents the proteomics-guided repositioning of bevacizumab and its
successful mitigation of neovascularization in CAPN5-NIV patients.
(The quoted text preserves the source PDF's line-break hyphenation in
"inhibi-tor" and "inflamma-tory".)
- name: Cryotherapy
description: >-
Retinal cryotherapy has been used in CAPN5-NIV: a severely affected
patient with progressive vitreoretinopathy and recurrent vitreous
hemorrhages received multiple cryotherapy treatments. Disease-specific
indication and outcome data are limited to single-case experience.
treatment_term:
preferred_term: Cryotherapy
term:
id: NCIT:C40030
label: Cryotherapy
evidence:
- reference: PMID:29040051
reference_title: Two Novel CAPN5 Variants Associated with Mild and Severe Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy Phenotypes.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
He had multiple cryotherapy treatments, left eye ruthenium plaque
brachytherapy and underwent bilateral pars plana vitrectomies.
explanation: >-
Documents multiple cryotherapy treatments used to manage progressive
vasoproliferative CAPN5-NIV disease.
- name: Ruthenium Plaque Brachytherapy
description: >-
Ruthenium plaque brachytherapy has been used in CAPN5-NIV: a severely
affected patient with progressive vitreoretinopathy and recurrent
vitreous hemorrhages received left-eye plaque brachytherapy.
Disease-specific indication and outcome data are limited to single-case
experience.
treatment_term:
preferred_term: Brachytherapy
term:
id: NCIT:C15195
label: Brachytherapy
evidence:
- reference: PMID:29040051
reference_title: Two Novel CAPN5 Variants Associated with Mild and Severe Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy Phenotypes.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
He had multiple cryotherapy treatments, left eye ruthenium plaque
brachytherapy and underwent bilateral pars plana vitrectomies.
explanation: >-
Documents left-eye ruthenium plaque brachytherapy used for advanced
vasoproliferative CAPN5-NIV disease.
- name: Pars Plana Vitrectomy
description: >-
Pars plana vitrectomy has been used in the surgical management of
advanced CAPN5-NIV: a severely affected patient with progressive
vitreoretinopathy, recurrent vitreous hemorrhages, and subsequent
tractional retinal detachments underwent bilateral vitrectomies.
Disease-specific indication and outcome data are limited to single-case
experience.
treatment_term:
preferred_term: vitrectomy
term:
id: NCIT:C50837
label: Vitrectomy
evidence:
- reference: PMID:29040051
reference_title: Two Novel CAPN5 Variants Associated with Mild and Severe Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy Phenotypes.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
He had multiple cryotherapy treatments, left eye ruthenium plaque
brachytherapy and underwent bilateral pars plana vitrectomies.
explanation: >-
Documents pars plana vitrectomy as part of the surgical management of
advanced CAPN5-NIV.
- name: Steroid-Sparing Immunosuppression
description: >-
Systemic immunosuppression is used for substantial vascular
leakage/inflammation, but CAPN5-NIV patients characteristically fail
conventional agents including anti-TNF-alpha therapy (infliximab),
consistent with normal vitreous TNF-alpha levels and a treatment-resistant
biology distinct from classic autoimmune uveitis.
treatment_term:
preferred_term: immune suppressant agent therapy
term:
id: NCIT:C15261
label: Immunosuppressive Therapy
evidence:
- reference: PMID:31110225
reference_title: Proteomic insight into the pathogenesis of CAPN5-vitreoretinopathy.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
these patients are left with few treatment options and fail
conventional immunosuppressive therapy, such as oral corticosteroids
and infliximab
explanation: >-
Documents the treatment-resistance to conventional immunosuppression,
including anti-TNF therapy (infliximab), that distinguishes CAPN5-NIV
biology.
Deep research results are used as seeds for research; they do not undergo the same validation as the main records and may contain errors. How we use deep research.
Create: CAPN5-Related Vitreoretinopathy (ADNIV, MONDO:0100450) · 2026-07-17T16:27:41Z · View source
De-novo curation of CAPN5-related vitreoretinopathy (ADNIV/NIV/VRNI, OMIM:193235) from issue #4008's Acquired/Common retinopathy list. Sourced via a claude_code deep-research run (research/CAPN5-Related_Vitreoretinopathy-deep-research-claude_code.md, 16 web searches, 20 citations) after falcon returned a transient network error; NEC preflight passed (gene CAPN5/HGNC:1482 and OMIM:193235 both match the MONDO:0100450 record). 6-node pathophysiology chain: CAPN5 gain-of-function protease hyperactivation -> aberrant photoreceptor synaptic proteolysis -> innate/adaptive autoimmune uveitis (branches to) -> oxidative-stress photoreceptor degeneration (conforms_to photoreceptor_degeneration#Photoreceptor Metabolic and Oxidative Stress) and opticin-loss/neovascularization -> fibrotic proliferative vitreoretinopathy and blindness (conforms_to fibrotic_response#Architectural Distortion and Organ Dysfunction). Modeled canonical gain-of-function vs. refuted-in-text haploinsufficiency as mechanistic_hypotheses (DEPRECATED status, since REFUTED is not a valid enum value). Three has_subtypes capturing the genotype-severity spectrum (Classic catalytic-domain, Mild regulatory-domain G376S, Syndromic Severe de novo R289W with hearing loss/developmental delay). 7 PMIDs fetched and verified (23055945, 23861576, 25994508, 29040051, 29472286, 31110225, 32274441); all evidence_source classifications checked (MODEL_ORGANISM kept distinct from HUMAN_CLINICAL for the mouse-model claims). Two snippet fixes needed during validation: trimmed a bracketed citation-number artifact ('[32]') that the reference validator could not match despite being an exact quote, and rewrote a TNF-alpha snippet to avoid the Greek alpha character (same category of Windows-local encoding mismatch seen on other entries this session -- both were exact matches under manual whitespace-normalized substring checks). New MONDO:0100450 term manually appended to cache/mondo/terms.csv and cache/enums/diseaseterm_*.csv (does not auto-populate). Note: 'just validate' on this Windows machine has a reproducible side effect of touching all ~2472 references_cache/*.md files (reference_id frontmatter re-quoting) plus intermittently mojibake-corrupting two unrelated MONDO rows -- both were reverted before staging so the commit is scoped to just this entry's files.
Overview: CAPN5-related vitreoretinopathy — most commonly termed Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy (ADNIV), and listed in OMIM as Vitreoretinopathy, Neovascular Inflammatory (VRNI) — is a rare, progressive, autosomal dominant autoinflammatory/autoimmune eye disease caused by gain-of-function missense variants in CAPN5 (calpain-5). It is a hereditary intraocular disease that sequentially mimics three common causes of blindness: it presents first as posterior uveitis, then evolves to resemble retinitis pigmentosa, and finally proliferative diabetic retinopathy, ultimately progressing to phthisis bulbi and complete blindness (EyeWiki.
Key identifiers: - OMIM (phenotype): #193235 — VITREORETINOPATHY, NEOVASCULAR INFLAMMATORY; VRNI - OMIM (gene): 602537 — CALPAIN 5; CAPN5 - Gene: CAPN5, HGNC:1482, NCBI Gene ID 726, chromosome 11q13.5 (GRCh38: 11:77,066,971–77,126,155) - MONDO ID: MONDO:0100450 (CAPN5-related vitreoretinopathy) — confirmed in NORD/GARD listings - GTR/MedGen: C4721549 (Autosomal dominant neovascular inflammatory vitreoretinopathy) - Orphanet: listed under CAPN5-associated conditions (Orphanet gene page for CAPN5) - ICD-10/11:* No disease-specific code; typically coded under hereditary retinal dystrophy/uveitis codes (H35.5, H30.9)
Synonyms: Autosomal Dominant Neovascular Inflammatory Vitreoretinopathy (ADNIV); Neovascular Inflammatory Vitreoretinopathy (NIV); CAPN5-Neovascular Inflammatory Vitreoretinopathy (CAPN5-NIV); Calpain-5 retinopathy/retinal degeneration.
Data source type: Information is derived almost entirely from aggregated disease-level resources — primarily case series and extended-pedigree studies from a small number of research groups (notably the Mahajan/Stanford and Bassuk/Iowa laboratories), OMIM, GeneReviews-adjacent literature reviews, and mouse/zebrafish model studies — rather than large-scale EHR-derived cohorts, reflecting the disease's rarity (only a handful of kindreds and fewer than 10 distinct pathogenic variants reported worldwide as of the most recent literature).
Disease causal factors: ADNIV/VRNI is a purely monogenic disorder. It is caused by heterozygous, autosomal dominant, gain-of-function missense variants in CAPN5, which encodes the calcium-activated cysteine protease calpain-5. There is no known environmental, infectious, or multifactorial contribution to disease initiation — onset and course are governed by the causal variant itself (PMID 23055945).
Genetic risk factors: - Causal variants cluster in two structural regions of calpain-5: (1) the catalytic protease core, near the calcium-sensitive "gating loop" adjacent to the catalytic histidine (variants p.Arg243Leu, p.Leu244Pro, p.Lys250Asn, p.Gly267Ser, p.Arg289Trp), and (2) the C2/regulatory domain (p.Gly376Ser) (PMID 25856303; PMID 29040051). - Variant location and resultant degree of protease hyperactivation correlate with severity — catalytic-domain variants generally produce more severe, earlier-onset disease than the single reported regulatory (C2)-domain variant (PMID 29040051; PMID 32274441). - Family history/inheritance from an affected parent is the dominant risk factor given autosomal dominant transmission with reported complete penetrance in classic pedigrees, though incomplete/age-dependent penetrance has since been documented (see Section 9).
Environmental risk factors: None established. No toxin, occupational, dietary, or infectious exposure has been linked to onset or severity.
Protective factors: No genetic modifier or protective variant has been identified. No environmental/lifestyle factor has been shown to reduce risk or delay onset. Absence of the pathogenic CAPN5 allele is the only known "protective" factor; wild-type calpain-5 shows tightly calcium-regulated, membrane-localized activity that is lost in mutant alleles.
Gene-environment interactions: Not established. Disease expression appears driven by the retina's naturally high local calcium flux (from phototransduction), which interacts with the calcium-hypersensitized mutant enzyme to trigger pathology — this is a tissue-intrinsic biochemical interaction rather than a classic gene-environment (exogenous exposure) interaction (PMID 25994508).
ADNIV progresses through canonical, roughly decade-long stages, each with characteristic clinical signs (Mahajan et al., PMID 23055945; EyeWiki).
| Stage | Approx. duration | Key phenotype | Suggested HPO term(s) |
|---|---|---|---|
| I | ~1st decade of disease | Non-infectious posterior uveitis, vitreous cells, abnormal ERG (reduced b-wave) | Uveitis (HP:0000554), Vitritis, Abnormal electroretinogram (HP:0000512) |
| II | ~2nd decade | Retinitis-pigmentosa-like pigmentary photoreceptor degeneration, night blindness | Retinal pigment epithelial mottling (HP:0007737), Nyctalopia (HP:0000662), Retinal degeneration (HP:0000546) |
| III | ~3rd decade | Retinal/iris neovascularization resembling proliferative diabetic retinopathy, vascular dropout | Retinal neovascularization (HP:0007843), Iris neovascularization |
| IV | ~4th decade | Intraocular fibrosis, epiretinal/proliferative vitreoretinopathy, tractional retinal detachment | Vitreoretinal degeneration, Retinal detachment (HP:0000541), Vitreous hemorrhage (HP:0007843/HP:0011505) |
| V | Terminal | Phthisis bulbi, complete blindness | Phthisis bulbi (HP:0025438), Blindness (HP:0000618) |
Additional/shared phenotypic features across stages: - Cystoid macular edema (HP:0011505 area — Macular edema) - Cataract (HP:0000518), often nuclear sclerotic - Neovascular glaucoma (HP:0007843-adjacent; Glaucoma HP:0000501) - Chronic vitreous hemorrhage - CD3+ T-lymphocyte infiltration of iris, choroid, ciliary body, vitreous, and retina (largely T-cell predominant, occasional minor B-cell component <15% of infiltrate) (PMID 23861576) - Pigment clumping distinguishable from the bone-spicule pattern of typical retinitis pigmentosa
Syndromic/extraocular phenotype (severe end of spectrum — p.Arg289Trp): progressive sensorineural hearing loss (unresponsive to immunosuppression), developmental delay (language, social, quantitative reasoning), mild truncal hypotonia, nonspecific temporal lobe EEG abnormality, chronic diarrhea/constipation, band keratopathy, optic neuritis, and complete vision loss by age 5 (Velez et al., Mol Case Stud, PMC5983175). Suggested HPO terms: Sensorineural hearing impairment (HP:0000407), Global developmental delay (HP:0001263), Hypotonia (HP:0001252), Band keratopathy (HP:0007750).
Onset, severity, progression, frequency: - Onset: Classically second–third decade of life; documented range from age 3 (infancy/childhood) to as late as the 5th–7th decade for mild presentations (PMID 32274441). - Severity: Highly variable — from mild, incidentally-discovered peripheral pigmentary degeneration with preserved 6/6 vision (p.Gly376Ser) to catastrophic childhood-onset syndromic blindness with hearing loss (p.Arg289Trp). - Progression: Classically relentlessly progressive over ~40+ years through five stages to blindness, but a subset of patients (notably milder catalytic and the regulatory-domain variant) show slow, non-progressive or minimally progressive courses even into their 60s–70s. - Frequency: Because of extreme rarity, percentage-based phenotype frequencies across a large cohort are not established; findings are drawn from fewer than a dozen published kindreds/cases.
Quality of life impact: Progressive, bilateral, irreversible vision loss culminating in legal/complete blindness has profound impact on independence, employment, and mental health; chronic recurrent intraocular inflammation and repeated surgeries (vitrectomy, implant placement/exchange) add significant treatment burden. No disease-specific EQ-5D/SF-36 data were identified in the literature; QOL burden is inferred from the severity of visual and (in syndromic cases) auditory/neurodevelopmental impairment.
Causal gene: CAPN5 (calpain-5), HGNC:1482, NCBI Gene 726, OMIM *602537, chromosome 11q13.5. Encodes a 640-amino-acid calcium-activated cysteine protease.
Pathogenic variants identified to date (all heterozygous, germline, missense, gain-of-function):
| Variant (protein) | Nucleotide (CAPN5 mRNA) | Domain | Reported phenotype | PMID |
|---|---|---|---|---|
| p.Arg243Leu (R243L) | c.728G>T | Catalytic core, gating loop | Classic ADNIV, onset ~20s; mild variants also reported at 45/69 | 23055945 |
| p.Leu244Pro (L244P) | c.731T>C | Catalytic core, gating loop | Classic ADNIV | 23055945; family cohort 37782277 |
| p.Lys250Asn (K250N) | c.750G>T | Catalytic core, gating loop | Severe uveitis, retinal neovascularization/detachment | 25856303 |
| p.Gly267Ser (G267S) | c.799G>A | Catalytic domain (exon 6) | Severe, congenital nystagmus, early vitreoretinopathy | 29040051 |
| p.Gly376Ser (G376S) | c.1126G>A | C2/regulatory domain | Mild, incidental, near-normal vision at 19 | 29040051 |
| p.Arg289Trp (R289W) | c.865C>T | Catalytic domain | Most severe/syndromic: childhood blindness, hearing loss, developmental delay | Velez et al., PMC5983175 |
Modifier genes: None formally established; a case report describes co-segregating TYR (albinism) variants in one family without altering core ADNIV phenotype, but this is not a validated modifier.
Epigenetic information: Not reported for this disease.
Chromosomal abnormalities: None reported — disease is caused by point mutations, not structural chromosomal rearrangements. Original linkage mapping localized the locus to an ~22 Mb interval on 11q13, later refined to a 6 Mb interval between rs879380 and D11S1789 (PMID 23055945).
Suggested ontology terms: MONDO:0100450 (CAPN5-related vitreoretinopathy); HGNC:1482 (CAPN5); GO:0004198 (calcium-dependent cysteine-type endopeptidase activity); GO:0005509 (calcium ion binding).
Causal chain (upstream → downstream): 1. Molecular trigger: Heterozygous gain-of-function missense mutation in CAPN5 increases calcium sensitivity and catalytic activity of calpain-5 and causes its mislocalization from the photoreceptor cell membrane to the cytosol (PMID 23055945). 2. Cell-intrinsic effect: In the retina's naturally high-calcium synaptic environment (phototransduction), hyperactive mutant calpain-5 undergoes aberrant, promiscuous proteolysis of normal substrates at photoreceptor synapses, disrupting synaptic signaling — proteomic studies show early loss of synaptic proteins including neurexin-2 (NRXN2), glutamate receptor 4 (GluR4), neurofascin, and calsyntenin-1, correlating with the earliest clinical/electrophysiological finding, reduced ERG b-wave amplitude (PMID 31110225). 3. Innate immune activation: Mouse retina expressing mutant hCAPN5-R243L shows upregulation of Toll-like receptor pathway genes, chemokines, and cytokines, consistent with local innate immune activation (PMID 25994508). Human vitreous proteomics shows marked elevation of acute-phase/complement proteins (C1R, C6, C7, C8, C9), implicating complement-mediated innate immunity (PMID 31110225). 4. Adaptive autoimmune response: Dense CD3+ T-lymphocyte infiltration of the uvea, vitreous, and retina (with minor B-cell component) drives chronic autoimmune uveitis, likely via exposure of neo-epitopes generated by aberrant calpain proteolysis (PMID 23861576; PMID 31110225). 5. Oxidative stress and neurodegeneration: Loss of antioxidant defenses in vitreous (reduced SOD1, SOD3, peroxiredoxins, catalase, clusterin) contributes to progressive photoreceptor degeneration mimicking retinitis pigmentosa (PMID 31110225). 6. Angiogenesis: Downregulation of the anti-angiogenic protein opticin, alongside upregulated crystallins (CRYAA, CRYAB, CRYBB1) correlating with elevated VEGF, promotes pathologic retinal/iris neovascularization mimicking proliferative diabetic retinopathy (PMID 31110225). 7. Fibrosis/end-stage: Downregulation of the extracellular matrix proteoglycan versican (VCAN) disrupts normal vitreous structure, contributing to proliferative vitreoretinopathy, tractional retinal detachment, and eventual phthisis bulbi.
Molecular pathways: Calpain/cysteine protease proteolysis; Toll-like receptor signaling; complement activation (classical/terminal pathway); VEGF/angiogenesis signaling; oxidative stress response. - Suggested GO Biological Process terms: GO:0006508 (proteolysis), GO:0002250 (adaptive immune response), GO:0045087 (innate immune response), GO:0001525 (angiogenesis), GO:0006979 (response to oxidative stress), GO:0007268 (chemical synaptic transmission).
Protein dysfunction: Gain-of-function/dysregulation rather than misfolding — hyperactive, mislocalized protease (see Section 4). CAPN5 protein structure comprises a protease core (PC, domains I–II; crystal structure PDB 6P3Q, 2.8 Å) and a C-terminal C2 domain (loss of the classical calpain penta-EF-hand domain IV) that contributes to membrane localization and calcium-dependent activation (PMID 33811937).
Cell types involved: Photoreceptor cells (rods/cones) — primary site of CAPN5 expression (strong immunostaining in photoreceptor inner segments/nuclei; minimal in other retinal layers; CAPN5 transcript detected at 4.63 FPKM in human retina); infiltrating CD3+ T lymphocytes; retinal/iris vascular endothelial cells (neovascularization); retinal pigment epithelium and Müller glia (regeneration/stress response, per zebrafish data). Suggested CL terms: CL:0000210 (photoreceptor cell), CL:0000084 (T cell), CL:0002586 (retinal blood vessel endothelial cell), CL:0000636 (Müller cell).
Tissue damage mechanisms: Chronic inflammation-driven bystander photoreceptor degeneration, oxidative stress, aberrant angiogenesis with vascular leakage/hemorrhage, and progressive fibrotic scarring/traction leading to retinal detachment.
Molecular profiling data available: Vitreous proteomics (mass spectrometry) is the principal omics dataset published for this disease (PMID 31110225). No transcriptomic, metabolomic, lipidomic, single-cell, or spatial transcriptomic human datasets were identified. Mouse retinal transcriptome changes (Toll-like receptor pathway, chemokine/cytokine upregulation) are reported in the R243L transgenic model (PMID 25994508).
Organ level: - Primary organ: Eye (retina, vitreous, uvea/iris, choroid, ciliary body, lens, optic nerve). - Secondary/syndromic involvement (severe R289W variant only): inner ear (sensorineural hearing loss), central nervous system (developmental delay, EEG abnormalities), gastrointestinal tract (chronic diarrhea/constipation). - Body systems: primarily sensory/visual system; syndromic cases also involve auditory system and nervous system.
Tissue/cell level: - Neural retina — photoreceptor layer (rods and cones) is the principal site of CAPN5 expression and initial pathology. - Uveal tract (iris, ciliary body, choroid) — site of lymphocytic infiltration and neovascularization. - Vitreous — site of inflammatory cell infiltration, hemorrhage, and fibrotic membrane formation. - Retinal vasculature — site of neovascularization and vascular dropout. - Suggested CL terms: CL:0000210 (photoreceptor cell), CL:0000573 (retinal cone cell), CL:0000604 (retinal rod cell), CL:0000084 (T cell), CL:0000232 (erythrocyte, vitreous hemorrhage context).
Subcellular level: Plasma membrane (site of normal calpain-5 localization, lost in mutants); cytosol (site of mutant mislocalization); photoreceptor synaptic terminals (site of synaptic protein proteolysis). Suggested GO Cellular Component terms: GO:0005886 (plasma membrane), GO:0005829 (cytosol), GO:0098992 (photoreceptor ribbon synapse).
Localization: Bilateral in essentially all reported cases (autosomal dominant, systemically expressed gene); disease is generally symmetric, though stage/severity can vary somewhat between the two eyes of an individual. - Suggested UBERON terms: UBERON:0000966 (retina), UBERON:0003893 (vitreous body), UBERON:0001769 (choroid), UBERON:0001769/UBERON:0001770 (iris/uvea), UBERON:0000970 (eye).
Epidemiology: Extremely rare; one source estimates prevalence of NIV at ~1 in 1,000,000 (Sequencing.com educational summary, citing rare-disease estimates). Formal incidence/prevalence figures from Orphanet/GBD were not retrievable in this search — the disease is not separately tracked in most national registries given its rarity and historically limited number of characterized kindreds (fewer than 10 published families worldwide).
Inheritance pattern: Autosomal dominant, with the founding pedigrees showing complete penetrance (PMID 23055945). However, subsequent case reports of mild, late-onset presentations (age 45, 69) in R243L carriers suggest age-dependent and possibly incomplete penetrance/expressivity is more accurate for the broader mutation spectrum (PMID 32274441).
Penetrance: High/complete in classically studied large pedigrees; increasingly recognized as variable/age-dependent as more (mild) cases are identified.
Expressivity: Markedly variable, correlating with variant location and degree of protease hyperactivation — ranging from asymptomatic incidental peripheral pigmentary change to catastrophic syndromic childhood blindness with hearing loss and developmental delay (see Section 3/4). Six distinct pathogenic mutations reported to date, "each resulting in varying levels of protease hyperactivity with a direct correlation to clinical severity" (PMC7132063).
Genetic anticipation: Not reported/established for this disorder (not a repeat-expansion disease).
Germline mosaicism: Not specifically reported; one case (R289W) was confirmed de novo.
Founder effects: The large original ADNIV kindred is a well-characterized multigenerational American family; whether R243L represents a founder allele in that lineage specifically (rather than recurrent mutation) is consistent with dominant private-variant inheritance, though this is not formally established as a population founder effect.
Consanguinity: Not a relevant risk factor given the dominant (not recessive) inheritance pattern.
Carrier frequency: Not applicable in the traditional (recessive-carrier) sense; pathogenic alleles are essentially private/family-specific and absent from population databases (gnomAD/1000 Genomes/dbSNP), consistent with an ultra-rare, highly penetrant dominant disease allele.
Population demographics: No specific ethnic or geographic predilection has been established; reported kindreds are from the United States and United Kingdom. No sex predilection is reported (autosomal, both sexes affected, e.g., two affected sisters in the K250N pedigree). Age distribution spans childhood through the 7th decade depending on variant.
Clinical/ophthalmic tests: - Dilated fundus examination — vitreous cells, pigmentary changes, neovascularization, fibrosis, detachment. - Electroretinography (ERG) — early, characteristic finding of reduced/lost b-wave amplitude, often the earliest objective abnormality, later progressing to non-recordable cone/rod responses. - Fluorescein angiography (FA) — used serially (every 6–12 months in stable/low-leakage patients) to assess vascular leakage/non-perfusion, guiding treatment (laser, anti-VEGF). - Optical coherence tomography (OCT) — macular edema, epiretinal membrane, structural retinal changes. - Slit-lamp exam — cataract, band keratopathy, anterior chamber inflammation.
Biomarkers: Vitreous proteomic signature (elevated complement/acute-phase proteins C1R/C6/C7/C8/C9; reduced antioxidants SOD1/SOD3/catalase/peroxiredoxins/clusterin; altered crystallins and opticin) is a research-level biomarker panel, not yet a validated clinical diagnostic biomarker (PMID 31110225).
Histopathology: Immunohistochemistry of enucleated/explanted eyes shows dense CD3+ T-cell infiltration of uvea/vitreous/retina with minimal neutrophils/eosinophils/macrophages (PMID 23861576).
Genetic testing: - Single-gene CAPN5 sequencing (Sanger or targeted NGS) is the recommended diagnostic approach in patients with a phenotype suggestive of ADNIV, especially those with atypical/unexplained uveitis, atypical retinitis pigmentosa, or a family history of progressive vitreoretinopathy. - CAPN5 should be included in inherited retinal dystrophy gene panels, particularly for patients without a clear family history or classic combination of inflammation + vitreoretinopathy, since phenotype can mimic isolated uveitis or isolated RP. - Whole-exome sequencing (WES) has been the discovery method for all novel variants reported to date (linkage mapping + WES in the original family; WES/targeted panels in subsequent case reports), underscoring its utility when single-gene testing is uninformative or the phenotype is atypical/syndromic. - No specific CMA, karyotype, FISH, mitochondrial, or repeat-expansion testing is indicated, as this is a single-gene missense disorder. - The NIH Genetic Testing Registry (GTR) lists this condition under MedGen C4721549, though specific commercial test/lab listings were not retrievable in this search.
Differential diagnosis: - Idiopathic (non-infectious) posterior uveitis / panuveitis — mimicked in Stage I. - Autosomal dominant retinitis pigmentosa — mimicked in Stage II (distinguishing feature: ADNIV shows pigment clumps rather than classic bone-spicule pigmentation). - Proliferative diabetic retinopathy — mimicked in Stage III (absence of diabetes, family history, and early inflammatory history help distinguish). - Idiopathic vitreomacular traction, ischemic neovascular retinopathy — noted as common misdiagnoses in the absence of recognized family history. - Familial exudative vitreoretinopathy (FEVR) — differs by lacking prominent chronic autoimmune uveitis and by different causal genes (FZD4, LRP5, TSPAN12, NDP).
Screening: No population or newborn screening program exists given rarity; cascade genetic testing of at-risk relatives in known kindreds (with baseline ERG/FA) is the recommended approach, and early genetic diagnosis has been reported to expedite intervention before advanced fibrotic/detachment stages (Ophthalmology Advisor).
Survival/mortality: ADNIV/VRNI is a strictly ocular (or, rarely, oculo-syndromic) disease with no established impact on overall life expectancy in the classic (non-syndromic) form; mortality data are not applicable/reported.
Morbidity/function: - Classic natural history: progression through five stages over ~40 years culminating in complete blindness/phthisis bulbi. - Severe syndromic form (R289W): complete vision loss by age 5, plus profound sensorineural hearing loss and developmental delay — substantial multi-domain disability. - Mild forms (G376S, late-onset R243L): may retain good visual acuity (e.g., 6/6, 6/5) for years to decades with only peripheral, non-progressive or slowly progressive findings.
Disease course/complications: Cystoid macular edema, cataract, neovascular glaucoma, recurrent vitreous hemorrhage, tractional/rhegmatogenous retinal detachment, proliferative vitreoretinopathy, and fibrotic encapsulation of implanted steroid devices requiring repeat surgery (PMID 23785231).
Recovery potential: Structural damage (fibrosis, detachment, photoreceptor loss) is generally irreversible; treatment aims to slow progression and control inflammation/neovascularization rather than reverse damage. Even with steroid control of inflammation, degeneration and vision loss can persist (PMID 23861576).
Prognostic factors: Causal variant identity/domain location is the principal known prognostic factor (catalytic-domain variants → more severe; regulatory-domain variant → milder); age of onset also correlates inversely with severity in the limited case data available.
Pharmacotherapy: - Corticosteroids (topical, periocular, intravitreal, or oral) — mainstay for controlling active intraocular inflammation, but disease often shows incomplete/transient response, especially against the degenerative component. - Steroid-sparing systemic immunosuppression — used for patients with substantial vascular leakage/inflammation; however, "patients with CAPN5 fail conventional immunosuppressive therapy, such as oral corticosteroids and infliximab (anti-TNF-α)," indicating a treatment-resistant, non-classic-autoimmune biology (search synthesis of case literature). - Intravitreal corticosteroid implants (e.g., fluocinolone acetonide/Retisert) — used for sustained local anti-inflammatory delivery; recurrent implant placement reported in managed cohorts (PMID 23785231; c.731T>C family cohort, PMID 37782277). - Anti-VEGF intravitreal injections — used for retinal/iris neovascularization (Stage III).
Surgical/interventional: - Panretinal/focal laser photocoagulation for peripheral non-perfusion. - Pars plana vitrectomy for vitreous hemorrhage, epiretinal membrane, and tractional retinal detachment. - Surgical excision of fibrotic capsules around steroid implants to re-establish drug delivery in advanced proliferative disease (PMID 23785231). - Cataract extraction and glaucoma drainage device implantation (e.g., for rubeotic/neovascular glaucoma) as needed in advanced disease (PMID 29040051).
Supportive/monitoring: Regular follow-up with fundus exam and fluorescein angiography every 6–12 months for patients with minimal leakage; low-vision rehabilitation services for advanced disease.
Experimental/advanced therapeutics: No gene therapy, cell therapy, RNA-based therapy, or disease-specific clinical trial (ClinicalTrials.gov) was identified for CAPN5-NIV in this search. Given the gain-of-function mechanism, rational future strategies discussed in the literature include calpain-selective small-molecule inhibitors and, longer-term, allele-selective gene silencing (e.g., siRNA/ASO) approaches, but none are in reported clinical development for this indication.
Treatment outcomes: Overall reported as poor/limited — the condition is characterized in the literature as "poorly understood," with "limited therapeutic options" and frequent treatment resistance; the fibrotic/proliferative late-stage response is often refractory to local immunosuppression.
Treatment strategy/algorithm: Stage-based — anti-inflammatory therapy (topical/systemic/implant) in early inflammatory stages; anti-VEGF/laser for neovascular stage; surgical (vitrectomy, membrane peel, implant revision) for fibrotic/detachment stage; genetic diagnosis is advocated to be obtained early to guide monitoring intensity and family counseling/cascade testing (Ophthalmology Advisor).
Suggested MAXO terms: MAXO:0000275-class "corticosteroid therapy," "immunosuppressive therapy," "anti-VEGF therapy," "vitrectomy," "laser photocoagulation," "intravitreal drug delivery implant" (exact MAXO IDs should be confirmed against the current MAXO release).
Mouse models: - Capn5 germline knockout mice: Two independently generated null lines gave conflicting results — one reported viable, fertile null mice (some runted, dying ~2 months postnatally), while another reported the null allele as pre-implantation embryonic lethal. Critically, in the viable line, no retinal phenotype was observed, supporting that ADNIV pathology requires gain-of-function mutant protein rather than loss of wild-type function (PMID 23055945). - Transgenic hCAPN5-R243L retina-targeted mice: Lentiviral/transgenic expression of human mutant CAPN5(R243L) in mouse retina reproduces core disease features — loss of ERG b-wave, photoreceptor degeneration, protein extravasation, vitreous inflammation, retinal fibrosis, and CD3+ T-cell/immune gene upregulation (Toll-like receptor pathway, chemokines, cytokines) — validating this as the primary in vivo functional model of ADNIV (PMID 25994508; PMID 24381307). - MGI resource: Capn5, MGI:1100859.
Zebrafish models: - Zebrafish capn5 is expressed in the developing optic vesicle/embryonic brain and in newly differentiated photoreceptors, colocalizing with cone markers in the adult retina. - capn5 expression increases in models of chronic rod photoreceptor degeneration/regeneration and after acute light damage, localizing to surviving cones and a subset of Müller glia — leveraging zebrafish's unique capacity for retinal neuronal regeneration to study Capn5's role in degeneration/regeneration biology, a feature not available in mammalian models (Noel et al., PMC6054427).
In vitro/cellular models: - Heterologous expression (cultured cell lines) of wild-type vs. mutant CAPN5 constructs used to demonstrate membrane-to-cytosol mislocalization and altered calcium-dependent protease activity of disease variants (R243L, L244P, K250N, R289W) (PMID 23055945; PMID 25856303; PMC5983175). - Structural/biochemical studies of the recombinant CAPN5 protease core (crystal structure, PDB 6P3Q) and C2 domain, informing mechanistic modeling of how disease mutations alter the calcium-sensing gating loop (PMID 33811937).
Model limitations: No mouse or zebrafish model fully recapitulates the chronic, multi-decade, five-stage human disease course, nor the syndromic extraocular (hearing loss/developmental delay) features of the most severe human variant (R289W); most models focus on early inflammatory/degenerative endpoints rather than the full natural history including fibrosis and phthisis bulbi.
Research applications: These models have been used to establish the gain-of-function/mislocalization mechanism, to characterize innate/adaptive immune activation, and represent the platform on which future therapeutic testing (e.g., calpain inhibitors, gene-silencing approaches) would likely be evaluated preclinically.
Sources: - Calpain-5 Mutations Cause Autoimmune Uveitis, Retinal Neovascularization, and Photoreceptor Degeneration (PMID 23055945) - Lymphocyte infiltration in CAPN5 ADNIV (PMID 23861576) - Structural modeling of a novel CAPN5 mutation (PMID 25856303) - CAPN5 R243L mouse model (PMID 25994508) - Two novel CAPN5 variants (PMID 29040051) - Proteomic insight into CAPN5-vitreoretinopathy (PMID 31110225) - A novel de novo CAPN5 mutation with hearing loss/developmental delay (PMC5983175) - Phenotypic variance in Calpain-5 retinal degeneration (PMID 32274441) - The C2 domain of calpain 5 (PMID 33811937) - Surgical management of fibrotic encapsulation of fluocinolone implant (PMID 23785231) - ADNIV c.731T>C family cohort and literature review (PMID 37782277) - Functional validation of CAPN5 exome variant via lentiviral transduction (PMID 24381307) - Capn5 expression in healthy/regenerating zebrafish retina (PMC6054427) - OMIM #193235 — VRNI - OMIM *602537 — CAPN5 - EyeWiki — ADNIV - NORD/GARD — CAPN5-related vitreoretinopathy - NCBI GTR — C4721549 - CAPN5 Gene — GeneCards