Is ACTN3 p.Arg728Cys (c.2182C>T) pathogenic?

ACTN3 p.Arg728Cys (c.2182C>T) is classified Uncertain significance in ACTN3 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-04-17). AlphaMissense: likely pathogenic (0.6036); Ultra-rare (popmax 0.0609%, sas).

How common is ACTN3 p.Arg728Cys (c.2182C>T) in the general population?

ACTN3 p.Arg728Cys (c.2182C>T) is ultra-rare (popmax 0.0609%, sas) (gnomAD).

What do computational predictors say about ACTN3 p.Arg728Cys (c.2182C>T)?

AlphaMissense predicts likely pathogenic (score 0.6036) — an in-silico prediction, not a clinical call.

ACTN3 p.Arg728Cys

c.2182C>T · rs372825946 · VCV3141999

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely pathogenic

0.6036 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0609%, sas)

Missense predictors

2/2 damaging

AlphaMissense, SaProt

Computational evidence

Protein change
AlphaMissense	0.6036	likely pathogenic
SaProt	LLR -12.46	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 7.6	GERP 1.4, phastCons 1
Regional constraint	o/e 1.04	unconstrained · MANE · 7,830 bp · p 0.26 · regional, not allelic
Overall
CADD	33.0	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

Grpmax group 0.0609% South Asian · 55/90,330 alleles

Filtering AF 0.048% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0434%

Overall 0.00553% 89/1,608,620 alleles · ultra-rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.0609%	1,642
Middle Eastern	0.0495%	2,019
African / African-American	0.0227%	4,405
Remaining individualsnot grpmax-eligible	0.00642%	15,576
Admixed American	0.00169%	59,158
European (non-Finnish)	0.000764%	130,855

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: ACTN3
Protein: p.Arg728Cys
Coding: c.2182C>T
MANE Select: NM_001104
dbSNP: rs372825946
Type: single nucleotide variant
Location: chr11:66562028 (GRCh38)
Gene constraint: LOEUF 0.944 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 84.61 · 3 PDB
Residue 728: a UniProt-annotated variant site (very low expression, if any, at the protein level in skeletal muscle)

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.Ala251Thr 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

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-arg728cys (accessed [today's date]).

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