CAPN3

Chr 15

calpain 3

Also known as: CANP3, CANPL3, LGMD2, LGMD2A, LGMDD4, LGMDR1, nCL-1, p94

The protein is a muscle-specific calpain that functions as an intracellular protease and specifically binds to titin. Mutations cause limb-girdle muscular dystrophy with both autosomal recessive (type 2A/LGMDR1) and autosomal dominant (type 4/LGMDD4) inheritance patterns. The predicted mechanism involves gain-of-function effects.

GeneReviewsResearchSummary from RefSeq, OMIM, UniProt, Mechanism
MultiplemechanismLOEUF 0.96
VCEP Guidelines: Limb Girdle Muscular DystrophyReleased
ClinGen Panel
Clinical SummaryCAPN3
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Gene-Disease Validity (ClinGen)
autosomal recessive limb-girdle muscular dystrophy · ARDefinitive

Definitive — sufficient evidence for diagnostic panels

2 total gene-disease associations curated

Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
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ClinVar Variants
129 unique Pathogenic / Likely Pathogenic· 224 VUS of 600 total submissions
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GeneReview available — CAPN3
Authoritative clinical overview · Recommended first read
Open GeneReview ↗
Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.96LOEUF
pLI 0.000
Z-score 1.75
OE 0.73 (0.560.96)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
-0.03Z-score
OE missense 1.00 (0.931.08)
469 obs / 467.0 exp
Tolerant

Tolerant to missense variation

Observed / Expected Ratios
LoF OE0.73 (0.560.96)
00.351.4
Missense OE1.00 (0.931.08)
00.61.4
Synonymous OE1.15
01.21.6
LoF obs/exp: 36 / 49.2Missense obs/exp: 469 / 467.0Syn Z: -1.63
DN
0.6743th %ile
GOF
0.73top 25%
LOF
0.2776th %ile

This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative and gain-of-function). The Badonyi & Marsh model scores gain-of-function highest among its predictions, but genomic evidence (constraint, ClinVar variant spectrum, and literature) most strongly supports dominant-negative. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

DNprediction above median · 1 literature citation
GOFprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Literature Evidence

DNMoreover, the D705G mutation had a dominant negative effect on endogenous CAPN3 when expressed on a WT background.PMID:21624972

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

600 submitted variants in ClinVar

Classification Summary

Pathogenic55
Likely Pathogenic74
VUS224
Likely Benign215
Benign4
Conflicting11
55
Pathogenic
74
Likely Pathogenic
224
VUS
215
Likely Benign
4
Benign
11
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
39
4
11
1
55
Likely Pathogenic
46
22
5
1
74
VUS
1
192
20
11
224
Likely Benign
0
0
118
97
215
Benign
0
0
4
0
4
Conflicting
11
Total86218158110583

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

CAPN3 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →
Clinical Literature
Open Research Assistant →