Is CAPN3 p.Thr409= (c.1227A>G) pathogenic?

CAPN3 p.Thr409= (c.1227A>G) is classified Conflicting classifications of pathogenicity in CAPN3 (ClinVar, Conflicting submitters, 5 submitters; last evaluated 2026-01-26). Ultra-rare (popmax 0.0309%, nfe); Associated with autosomal recessive limb-girdle muscular dystrophy type 2A.

What condition is associated with CAPN3 p.Thr409= (c.1227A>G)?

CAPN3 p.Thr409= (c.1227A>G) is associated with autosomal recessive limb-girdle muscular dystrophy type 2A (ClinVar).

How common is CAPN3 p.Thr409= (c.1227A>G) in the general population?

CAPN3 p.Thr409= (c.1227A>G) is ultra-rare (popmax 0.0309%, nfe) (gnomAD).

CAPN3 p.Thr409=

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.1227A>G · rs111806046 · VCV281088

Conflicting classifications of pathogenicity Conflicting submitters

Classification

Conflicting classifications of pathogenicity

ClinVar

Review

Conflicting submitters ★☆☆☆

ClinVar · 5 submitters

gnomAD v4.1

Rare

ultra-rare (popmax 0.0309%, nfe)

Conditions

autosomal recessive limb-girdle muscular dystrophy type 2A

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -0.53	GERP -3.6
Overall
CADD	6.273	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0309% European (non-Finnish) · 364/1,179,880 alleles

Filtering AF 0.0282% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0272%

Overall 0.0234% 378/1,613,776 alleles · ultra-rare

Ancestry group	Frequency	1 in
European (non-Finnish)grpmax	0.0309%	3,241
Remaining individualsnot grpmax-eligible	0.0208%	4,806
Finnishnot grpmax-eligible	0.00156%	64,020

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.Thr409=
Coding: c.1227A>G
MANE Select: NM_000070
dbSNP: rs111806046
Type: single nucleotide variant
Location: chr15:42399525 (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 409: the calpain catalytic domain

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

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 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
CAPN3 c.499-1G>A Pathogenic ★★★ same condition
CAPN3 p.Ala702Val Pathogenic ★★★ same condition
CAPN3 p.Ala798Glu 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-thr409 (accessed [today's date]).

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