Is ACTN3 p.Ala251Thr (c.751G>A) pathogenic?

ACTN3 p.Ala251Thr (c.751G>A) is classified Uncertain significance in ACTN3 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-12-15). AlphaMissense: likely pathogenic (0.713); Absent from gnomAD v4.1.

How common is ACTN3 p.Ala251Thr (c.751G>A) in the general population?

ACTN3 p.Ala251Thr (c.751G>A) is absent from gnomAD v4.1 (gnomAD).

What do computational predictors say about ACTN3 p.Ala251Thr (c.751G>A)?

AlphaMissense predicts likely pathogenic (score 0.713) — an in-silico prediction, not a clinical call.

ACTN3 p.Ala251Thr

c.751G>A · VCV4837340

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely pathogenic

0.713 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

2/2 damaging

AlphaMissense, SaProt

Computational evidence

Protein change
AlphaMissense	0.713	likely pathogenic
SaProt	LLR -10.11	damaging
⇒ AlphaMissense and SaProt both call this damaging.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 12	GERP 2.4, phastCons 1
Regional constraint	o/e 1.04	unconstrained · MANE · 7,830 bp · p 0.26 · regional, not allelic
Overall
CADD	27.7	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean damaging — 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

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: ACTN3
Protein: p.Ala251Thr
Coding: c.751G>A
MANE Select: NM_001104
Type: single nucleotide variant
Location: chr11:66556177 (GRCh38)
Gene constraint: LOEUF 0.944 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 84.61 · 3 PDB
Residue 251: the calponin-homology (ch) 2 domain; an α-helix; the 'actin-binding' region

Full ACTN3 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Similar variants

ACTN3 p.Ala115Asp Uncertain significance ★ ⚠ same type
ACTN3 p.Ala149Thr Uncertain significance ★ ⚠ same type
ACTN3 p.Ala410Pro Uncertain significance ★ ⚠ same type
ACTN3 p.Ala410Val Uncertain significance ★ ⚠ same type
ACTN3 p.Ala460Val Uncertain significance ★ ⚠ same type
ACTN3 p.Ala469Gly Uncertain significance ★ ⚠ same type
ACTN3 p.Ala470Pro Uncertain significance ★ ⚠ same type
ACTN3 p.Ala533Val Uncertain significance ★ ⚠ 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/actn3-p-ala251thr (accessed [today's date]).

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