| Domain | DCM1J-specific finding | Evidence type/strength | Key ontology suggestions |
|---|---|---|---|
| Identity and identifiers | **Dilated cardiomyopathy 1J (DCM1J; historical CMD1J)** is a Mendelian cardio-auditory disorder mapped to **6q23–q24** and caused by heterozygous **EYA4** disruption. **OMIM 605362** is commonly mapped to DCM1J but should be verified against the live OMIM record before database ingestion. The disease-specific MONDO identifier was not established from the retrieved evidence. (pqac-00000003, pqac-00000007) | **Strong human genetic evidence:** linkage in two kindreds followed by causal-gene identification; nomenclature and database identifiers require live-database verification. | MONDO: dilated cardiomyopathy; MeSH: *Cardiomyopathy, Dilated*; gene: **EYA4** |
| Cardinal cardiac phenotype | Left-ventricular dilation and systolic dysfunction progress to congestive heart failure; severe reported outcomes included sudden death, transplantation, and transplant listing. Explanted/autopsy hearts showed cardiomegaly, hypertrophic myocytes, enlarged hyperchromatic nuclei, and interstitial fibrosis. (pqac-00000008) | **Human disease-specific evidence:** small, deeply phenotyped pedigrees; frequencies are not population estimates. | HP:0001644 Dilated cardiomyopathy; HP:0001635 Congestive heart failure; HP:0001712 Left ventricular hypertrophy; HP:0001707 Abnormality of the myocardium; HP:0001645 Sudden cardiac death |
| Cardinal auditory phenotype | Bilateral, symmetric, postlingual sensorineural hearing loss generally precedes cardiac disease and was moderate to severe by late adolescence in the original families. (pqac-00000007, pqac-00000008) | **Human disease-specific evidence:** consistent cosegregation and temporal precedence in the founding families. | HP:0000407 Sensorineural hearing impairment; HP:0008619 Bilateral sensorineural hearing impairment |
| Temporal development | Typical reported sequence: juvenile or late-adolescent hearing loss followed by clinically evident ventricular dysfunction and progressive heart failure after the fourth decade. Penetrance is age-related, so a young carrier may have hearing loss without echocardiographic DCM. (pqac-00000007) | **Human disease-specific evidence:** two pedigrees; onset and progression remain imprecisely quantified outside these families. | HP:0003621 Juvenile onset; HP:0003581 Adult onset; HP:0003676 Progressive |
| Inheritance | Autosomal dominant transmission with age-dependent penetrance and variable expressivity. The original linkage analysis assumed 95% penetrance for modeling, but this is not an empirically established lifetime penetrance estimate. (pqac-00000007, pqac-00000008, pqac-00000019) | **Strong segregation/linkage evidence:** maximum LOD **4.88** at D6S2411 in a 29-member kindred; causal interval was 2.8 cM. | HP:0000006 Autosomal dominant inheritance; HP:0003829 Incomplete penetrance; GENO: heterozygous genotype |
| Causal gene and protein | **EYA4** encodes a 638-amino-acid transcriptional cofactor with an N-terminal variable/transactivation region and a conserved C-terminal Eya domain possessing tyrosine-phosphatase and protein-interaction functions. EYA4 cooperates with SIX-family transcription factors. (pqac-00000010) | **Human genetics plus molecular-functional evidence.** EYA4 also causes hearing-loss-only DFNA10, making variant-level phenotype interpretation essential. | HGNC:3518 **EYA4**; GO:0003712 transcription coregulator activity; GO:0004725 protein tyrosine phosphatase activity; GO:0005634 nucleus; GO:0005737 cytoplasm |
| E193 variant | The founding **E193** allele is a heterozygous approximately **4,846-bp deletion** causing a frameshift after residue 193, 29 novel residues, and premature termination; it is associated with hearing impairment followed by late-onset DCM. (pqac-00000000, pqac-00000010) | **Disease-specific human and transgenic-model evidence.** Historical protein-level shorthand is reported; current HGVS genomic/cDNA notation requires transcript/build reconciliation. | Sequence Ontology: frameshift_variant; SO:0001587 stop_gained; GENO: heterozygous |
| E215 variant | A second heterozygous truncating allele, termed **E215**, produced similar cardio-auditory features, and mutant protein was detectable in myocardium. (pqac-00000000, pqac-00000010) | **Disease-specific but limited evidence:** very few affected individuals; contemporary ClinVar/ACMG classification and complete HGVS description should be verified. | Sequence Ontology: frameshift_variant or stop_gained, subject to HGVS verification |
| Genotype–phenotype caution | Many EYA4 truncating or splice variants cause isolated DFNA10 hearing loss without DCM. A p.Gln393Ter carrier had only minor ECG/mitral findings without LV dilation or impaired contractility, and early N-terminal truncation has also been reported without cardiac disease. Mutation position alone therefore does not reliably predict DCM1J. (pqac-00000001, pqac-00000002, pqac-00000003) | **Moderate evidence against a simple domain rule:** multiple hearing-loss families and patient-level cardiac assessments; long-term cardiac follow-up is incomplete in some reports. | MONDO: DFNA10; HP:0000407 Sensorineural hearing impairment; ClinGen/ACMG variant-level assessment |
| Proposed molecular mechanism | Wild-type EYA4–SIX1 represses **CDKN1B/p27Kip1** transcription. E193 behaves experimentally as a dominant-negative perturbation, increasing p27, reducing CK2α activity and HDAC2 phosphorylation, and disrupting the hypertrophic stress-response program; chronic imbalance is proposed to cause maladaptive remodeling and DCM. (pqac-00000009, pqac-00000010, pqac-00000011) | **Mechanistically suggestive, not fully proven in patients:** demonstrated in cultured cardiomyocytes and transgenic mice; dominant-negative action remains partly inferential. | GO:0045892 negative regulation of DNA-templated transcription; GO:0008285 negative regulation of cell population proliferation; GO:0006338 chromatin remodeling; GO:0003300 cardiac muscle hypertrophy |
| Tissue and cell targets | Principal targets are ventricular myocardium/cardiomyocytes and cochlear sensory structures. Secondary systemic manifestations arise from low cardiac output and congestion rather than established primary EYA4 injury in other organs. (pqac-00000007, pqac-00000010) | **Human phenotyping plus expression/model evidence.** The exact cochlear cell subtype responsible for human disease is not fully resolved. | CL:0000746 cardiac muscle cell; CL:0000202 auditory hair cell; UBERON:0000948 heart; UBERON:0002084 heart left ventricle; UBERON:0001844 cochlea |
| Diagnostic approach | Diagnose DCM by echocardiographic/CMR evidence of ventricular dilation and systolic dysfunction after excluding coronary disease, abnormal loading, and secondary causes. Obtain ECG, rhythm monitoring, BNP/NT-proBNP, troponin, audiometry, and a three-to-four-generation pedigree. Confirm with sequencing and deletion/duplication analysis that includes **EYA4**; test relatives for a familial pathogenic/likely pathogenic variant. (pqac-00000008, pqac-00000012, pqac-00000014) | **Mixed:** DCM1J-specific support for cardiac/audiologic surveillance; testing workflow largely extrapolated from contemporary general-DCM guidelines. | LOINC: echocardiography, cardiac MRI, ECG, BNP/NT-proBNP, troponin and pure-tone audiometry; NCIT:C15709 Genetic Testing |
| Treatment | No EYA4-specific disease-modifying therapy exists. Treat symptomatic reduced-EF DCM with guideline-directed heart-failure therapy, diuretics for congestion, and individualized arrhythmia/thromboembolism management; consider ICD/CRT according to standard criteria and transplantation or mechanical circulatory support for refractory advanced disease. Hearing aids or cochlear implantation may address auditory disability. (pqac-00000012, pqac-00000013) | **General-DCM/hearing-loss extrapolation:** not tested specifically in DCM1J; genotype-specific response rates are unavailable. | NCIT:C15291 Pharmacologic Therapy; NCIT:C804 Implantable Cardioverter-Defibrillator; NCIT:C122929 Cardiac Resynchronization Therapy; NCIT:C15288 Organ Transplantation; NCIT:C66897 Hearing Aid; NCIT:C15717 Cochlear Implantation |
| Prevention and surveillance | Primary prevention of the germline disorder is unavailable. Secondary prevention consists of genetic counseling, cascade testing, serial ECG/echo or CMR and audiometry in carriers, and early heart-failure treatment. Non-carriers of a well-established familial pathogenic variant generally do not require lifelong cardiomyopathy surveillance. (pqac-00000007, pqac-00000012) | **Guideline-supported extrapolation** reinforced by the presymptomatic auditory marker in the founding families. Optimal EYA4-specific surveillance intervals are unknown. | NCIT:C15241 Genetic Counseling; NCIT:C17173 Screening; HP:0003829 Incomplete penetrance |
| Epidemiology | DCM1J prevalence, incidence, carrier frequency, sex ratio, founder effects, and population distribution are unknown. Historical general-DCM prevalence of **36.5 per 100,000** and familial proportions of 25–30% must not be assigned to DCM1J. (pqac-00000007) | **Insufficient disease-specific epidemiologic evidence:** only a few families/cases; ascertainment is enriched through hearing-loss and cardiomyopathy clinics. | Orphanet rare-disease designation to verify; epidemiology fields should be recorded as “unknown” |
| Mouse and cellular models | Cardiac-specific Eya4 overexpression caused age-dependent hypertrophy without obvious baseline functional impairment; E193-overexpressing mice developed a DCM-like phenotype, and pressure overload worsened both. Neonatal rat and adult mouse cardiomyocytes reproduced opposing EYA4/E193 effects on p27, CK2α, HDAC2, protein synthesis, and cell size. (pqac-00000009, pqac-00000010, pqac-00000011) | **Strong experimental support for pathway direction, moderate support for human mechanism:** transgenic overexpression may not reproduce endogenous heterozygous dosage or temporal expression. | NCBI Taxon:10090 *Mus musculus*; NCBI Taxon:10116 *Rattus norvegicus*; CL:0000746 cardiac muscle cell; GO:0003300 cardiac muscle hypertrophy |
| Zebrafish and other-species evidence | Zebrafish Eya4 studies support conserved roles in sensory-system development and regulation of Na⁺/K⁺-ATPase, but they do not establish a faithful DCM1J cardiac phenotype. No validated naturally occurring veterinary DCM1J counterpart was identified. (pqac-00000001, pqac-00000003) | **Indirect comparative evidence:** useful for conserved EYA4 biology, weak for DCM1J cardiac recapitulation. | NCBI Taxon:7955 *Danio rerio*; GO:0007605 sensory perception of sound; GO:0005890 sodium:potassium-exchanging ATPase complex |


*Table: Evidence-calibrated summary of Dilated Cardiomyopathy 1J identity, phenotypes, genetics, mechanism, clinical management, epidemiologic limitations, and experimental models. Disease-specific findings are distinguished from general-DCM extrapolations.*