Congenital fiber-type disproportion myopathy: genes and variants
Explore variant evidence for Congenital fiber-type disproportion myopathy across 5 analyzed proteins (MYH7, RYR1, SELENON, MLC1, MYL2). Linked ClinVar records include 6 pathogenic or likely pathogenic variants, 52 variants of uncertain significance and 6 with conflicting classifications.
Coverage includes proteins already analyzed in CATVariant, not every gene involved in this condition. Database links are associations, not an assessment of clinical gene–disease validity. Computable evidence prioritizes variants for expert review and does not reclassify them. Source labels are pooled across this disease family.
Data updated 2026-10-10. Automated aggregation, not a clinical review date.
Download variant evidence (CSV)
Genes linked to Congenital fiber-type disproportion myopathy
MYH7: Myosin-7
Its beta-myosin motor converts ATP hydrolysis into force within cardiac and slow-skeletal-muscle sarcomeres. Pathogenic variants are major causes of hypertrophic and dilated cardiomyopathy and can also produce inherited skeletal myopathies.
6 ClinVar pathogenic / likely pathogenic and 55 uncertain variants in MYH7 have source records linked to Congenital fiber-type disproportion myopathy. Association strength is not clinical gene validity.
RYR1: Ryanodine receptor 1
It releases calcium from the skeletal-muscle sarcoplasmic reticulum when Cav1.1 senses membrane depolarization, directly coupling excitation to contraction. Pathogenic variants cause malignant-hyperthermia susceptibility and a broad spectrum of congenital RYR1-related myopathies.
0 ClinVar pathogenic / likely pathogenic and 3 uncertain variants in RYR1 have source records linked to Congenital fiber-type disproportion myopathy. Association strength is not clinical gene validity.
SELENON: Selenoprotein N
It helps maintain redox and calcium homeostasis within the endoplasmic reticulum of skeletal muscle, particularly during oxidative and mechanical stress. Biallelic loss-of-function variants cause SELENON-related myopathy, often with axial weakness, rigid spine, and disproportionate respiratory impairment.
0 ClinVar pathogenic / likely pathogenic and 0 uncertain variants in SELENON have source records linked to Congenital fiber-type disproportion myopathy. Association strength is not clinical gene validity.
MLC1: Membrane protein MLC1
A multi-pass membrane protein found mainly in brain astrocytes. It may support transport at the blood-brain and brain-cerebrospinal-fluid barriers and helps astrocytes respond to osmotic changes, while MLC1 disruption causes megalencephalic leukoencephalopathy with subcortical cysts.
0 ClinVar pathogenic / likely pathogenic and 0 uncertain variants in MLC1 have source records linked to Congenital fiber-type disproportion myopathy. Association strength is not clinical gene validity.
MYL2: Myosin regulatory light chain 2, ventricular/cardiac muscle isoform
It modulates cardiac myosin-head mechanics and phosphorylation-dependent force generation in ventricular sarcomeres. Pathogenic variants are an established cause of familial hypertrophic cardiomyopathy and can also produce other cardiomyopathy phenotypes.
0 ClinVar pathogenic / likely pathogenic and 0 uncertain variants in MYL2 have source records linked to Congenital fiber-type disproportion myopathy. Association strength is not clinical gene validity.
ClinVar pathogenic and likely pathogenic variants linked to Congenital fiber-type disproportion myopathy
| Variant | Position | Protein part | Clinical label |
|---|---|---|---|
| MYH7 R694H | 694 | Myosin motor | Pathogenic / likely pathogenic (★★) |
| MYH7 R1500W | 1500 | Coiled coil | Pathogenic / likely pathogenic (★★) |
| MYH7 R663S | 663 | Myosin motor | Pathogenic / likely pathogenic (★★) |
| MYH7 R858C | 858 | Coiled coil | Pathogenic / likely pathogenic (★★) |
| MYH7 E930Q | 930 | Coiled coil | Pathogenic / likely pathogenic (★★) |
| MYH7 P731R | 731 | Myosin motor | Pathogenic / likely pathogenic (★) |
Same protein, different disease
- Hypertrophic cardiomyopathy also has ClinVar records linked to MYH7 variants; they fall mostly in different places as the Congenital fiber-type disproportion myopathy variants (239 pathogenic / likely pathogenic).
- Cardiomyopathy also has ClinVar records linked to MYH7 variants; they fall mostly in different places as the Congenital fiber-type disproportion myopathy variants (24 pathogenic / likely pathogenic).
- Dilated cardiomyopathy also has ClinVar records linked to MYH7 variants; they fall mostly in different places as the Congenital fiber-type disproportion myopathy variants (21 pathogenic / likely pathogenic).
- Primary dilated cardiomyopathy also has ClinVar records linked to MYH7 variants; they fall mostly in different places as the Congenital fiber-type disproportion myopathy variants (15 pathogenic / likely pathogenic).
- Hyaline body myopathy also has ClinVar records linked to MYH7 variants; they fall mostly in different places as the Congenital fiber-type disproportion myopathy variants (13 pathogenic / likely pathogenic).
Diseases related to Congenital fiber-type disproportion myopathy
- Myopathy, also linked to MYH7, RYR1 and SELENON
- Hypertrophic cardiomyopathy, also linked to MYH7 and MYL2
- Cardiomyopathy, also linked to MYH7 and MYL2
- Dilated cardiomyopathy, also linked to MYH7
- Arrhythmogenic right ventricular dysplasia, also linked to MYH7
- Primary dilated cardiomyopathy, also linked to MYH7
- Primary familial hypertrophic cardiomyopathy, also linked to MYH7
- Hyaline body myopathy, also linked to MYH7
- Heart disease, also linked to MYL2
- Left ventricular noncompaction, also linked to MYH7
- Muscular dystrophy, also linked to SELENON
- Primary familial dilated cardiomyopathy, also linked to MYH7
Frequently asked questions
Which genes have records linked to Congenital fiber-type disproportion myopathy?
This view contains 5 analyzed proteins: MYH7, RYR1, SELENON, MLC1, MYL2. Links come from clinical records and association databases. They do not imply that every listed gene is a validated cause, and missing genes may not yet be analyzed.
What do the clinical classifications mean?
Linked records include 6 pathogenic or likely pathogenic variants, 52 variants of uncertain significance and 6 with conflicting classifications. Labels summarize source records; multi-condition records may not make a separate assertion for this disease. Check the original record and review status.
Does the evidence score change a VUS classification?
No. 0 VUS or conflicting variants reach the likely-pathogenic points range on the computable criteria available here. This is a research prioritization signal, not a clinical classification. Patient, family and other required evidence may be missing.
Can I download the variant evidence?
Download the CSV for all 70 variants in the selected disease scope, including clinical labels, review status, evidence criteria, predictor scores, functional measurements and population frequency where available.
About this data
Variant–disease links come from ClinVar, Open Targets and UniProt, pooled from eligible public CATVariant analyses of each human protein. Evidence scores use the ACMG/AMP Bayesian points scale with computable criteria only (position among known disease variants, rarity in gnomAD, calibrated predictors, deep mutational scanning); there is no family or patient data, so they prioritise variants for expert review and never classify them.
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