Is CAPN3 p.Arg493Trp (c.1477C>T) pathogenic?

CAPN3 p.Arg493Trp (c.1477C>T) is classified Pathogenic/Likely pathogenic in CAPN3 (ClinVar, Multiple submitters, 9 submitters; last evaluated 2025-08-25). AlphaMissense: likely pathogenic (0.7588); Very rare (popmax 0.00669%, eas); Associated with autosomal recessive limb-girdle muscular dystrophy type 2A.

What condition is associated with CAPN3 p.Arg493Trp (c.1477C>T)?

CAPN3 p.Arg493Trp (c.1477C>T) is associated with autosomal recessive limb-girdle muscular dystrophy type 2A, muscular dystrophy, limb-girdle, autosomal dominant 4 (ClinVar).

How common is CAPN3 p.Arg493Trp (c.1477C>T) in the general population?

CAPN3 p.Arg493Trp (c.1477C>T) is very rare (popmax 0.00669%, eas) (gnomAD).

What do computational predictors say about CAPN3 p.Arg493Trp (c.1477C>T)?

AlphaMissense predicts likely pathogenic (score 0.7588) — an in-silico prediction, not a clinical call.

CAPN3 p.Arg493Trp

Q: How is Calpain-3-related limb-girdle muscular dystrophy R1 inherited?

Typically Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

c.1477C>T · rs557164942 · VCV193792

Pathogenic/Likely pathogenic Multiple submitters

Classification

Pathogenic/Likely pathogenic

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 9 submitters

AlphaMissense

likely pathogenic

0.7588 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00669%, eas)

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

autosomal recessive limb-girdle muscular dystrophy type 2A

Computational evidence

Protein change
AlphaMissense	0.7588	likely pathogenic ✓ concordant with ClinVar
REVEL	0.913	moderately pathogenic-leaning
SaProt	LLR -13.99	damaging
⇒ AlphaMissense, REVEL and SaProt all call this damaging.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 2.6	GERP -0.26, phastCons 1
Regional constraint	o/e 0.96	unconstrained · MANE · 52 kb · p 0.21 · regional, not allelic
Overall
CADD	33.0	PHRED · no single calibrated threshold — expert panels disagree

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00669% East Asian · 3/44,840 alleles

Filtering AF 0.00177% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000892%

Overall 0.00149% 24/1,614,010 alleles · very rare

Ancestry group	Frequency	1 in
East Asiangrpmax	0.00669%	14,947
South Asian	0.0022%	45,532
European (non-Finnish)	0.00161%	62,103

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: CAPN3
Protein: p.Arg493Trp
Coding: c.1477C>T
MANE Select: NM_000070
dbSNP: rs557164942
Type: single nucleotide variant
Location: chr15:42401763 (GRCh38)
Gene constraint: LOEUF 0.896 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 79.18 · 5 PDB
Residue 493: the 'domain iii' region; a UniProt-annotated variant site (in lgmdr1)

Full CAPN3 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

autosomal recessive limb-girdle muscular dystrophy type 2A — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: muscular dystrophy, limb-girdle, autosomal dominant 4

For Calpain-3-related limb-girdle muscular dystrophy R1 (Orphanet):

Inheritance: Autosomal recessive
Onset: Adolescent, Adult, Childhood
Prevalence: 1-9 / 100 000 (Europe)

Similar variants

CAPN3 p.Arg493Gln Uncertain significance ★★ ⚠ same residue
CAPN3 p.Arg493Gly Conflicting classifications of pathogenicity ★ ⚠ same residue
CAPN3 p.Arg493Leu Uncertain significance ★ same residue
CAPN3 c.1115+5G>C Pathogenic ★★★ same condition
CAPN3 c.1194-2A>G Pathogenic ★★★ same condition
CAPN3 c.1194-9A>G Pathogenic ★★★ same condition
CAPN3 c.1746-20C>G Pathogenic ★★★ same condition
CAPN3 c.1993-1G>A Pathogenic ★★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/capn3-p-arg493trp (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown