Is CAPN1 p.Arg326Trp (c.976C>T) pathogenic?

CAPN1 p.Arg326Trp (c.976C>T) is classified Uncertain significance in CAPN1 (ClinVar, Single submitter, 1 submitter; last evaluated 2022-06-09). AlphaMissense: likely benign (0.1721); Very rare (popmax 0.0044%, sas).

How common is CAPN1 p.Arg326Trp (c.976C>T) in the general population?

CAPN1 p.Arg326Trp (c.976C>T) is very rare (popmax 0.0044%, sas) (gnomAD).

What do computational predictors say about CAPN1 p.Arg326Trp (c.976C>T)?

AlphaMissense predicts likely benign (score 0.1721) — an in-silico prediction, not a clinical call.

CAPN1 p.Arg326Trp

c.976C>T · rs1398824643 · VCV1932287

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.1721 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.0044%, sas)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Computational evidence

Protein change
AlphaMissense	0.1721	likely benign
REVEL	0.097	moderately benign-leaning
SaProt	LLR -6.93	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 2.8	GERP -1.1, phastCons 1
Regional constraint	o/e 0.85	unconstrained · MANE · 29 kb · p 4.3e-06 · regional, not allelic
Overall
CADD	25.2	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean tolerated — a triage signal, not a reclassification

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

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0044% South Asian · 4/90,892 alleles

Filtering AF 0.00143% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000892%

Overall 0.00124% 20/1,613,016 alleles · very rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.0044%	22,723
Admixed American	0.00167%	59,856
Remaining individualsnot grpmax-eligible	0.0016%	62,428
European (non-Finnish)	0.00119%	84,253

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: CAPN1
Protein: p.Arg326Trp
Coding: c.976C>T
MANE Select: NM_005186
dbSNP: rs1398824643
Type: single nucleotide variant
Location: chr11:65188460 (GRCh38)
Gene constraint: LOEUF 0.977 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 90.03 · 5 PDB
Residue 326: the calpain catalytic domain

Full CAPN1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Similar variants

CAPN1 p.Arg326= Likely benign ★ same residue
CAPN1 c.1605+5G>A Pathogenic/Likely pathogenic ★★ same type
CAPN1 c.267+2T>C Pathogenic/Likely pathogenic ★★ same type
CAPN1 c.338-1G>A Pathogenic ★★ same type
CAPN1 c.759+1G>A Pathogenic ★★ same type
CAPN1 c.843+1G>C Pathogenic/Likely pathogenic ★★ same type
CAPN1 c.929+2T>A Likely pathogenic ★★ same type
CAPN1 p.Arg285Ter Pathogenic/Likely pathogenic ★★ same type

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/capn1-p-arg326trp (accessed [today's date]).

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