Is ACTG1 p.Ser300= (c.900G>A) pathogenic?

ACTG1 p.Ser300= (c.900G>A) is classified Likely benign in ACTG1 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-08-11). Very rare (popmax 0.00833%, amr); Associated with autosomal dominant nonsyndromic hearing loss 20.

What condition is associated with ACTG1 p.Ser300= (c.900G>A)?

ACTG1 p.Ser300= (c.900G>A) is associated with autosomal dominant nonsyndromic hearing loss 20, Baraitser-winter syndrome 2 (ClinVar).

How common is ACTG1 p.Ser300= (c.900G>A) in the general population?

ACTG1 p.Ser300= (c.900G>A) is very rare (popmax 0.00833%, amr) (gnomAD).

ACTG1 p.Ser300=

c.900G>A · rs367966804 · VCV2040455

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.00833%, amr)

Conditions

autosomal dominant nonsyndromic hearing loss 20

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 -15	GERP -3.4
Overall
CADD	0.018	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00833% Admixed American · 5/60,002 alleles

Filtering AF 0.00323% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00207%

Overall 0.00279% 45/1,613,906 alleles · very rare exomes 43/1,461,726 · genomes 2/152,180 · joint denominator

Ancestry group	Frequency	1 in
Admixed Americangrpmax	0.00833%	12,000
Remaining individualsnot grpmax-eligible	0.0048%	20,829
East Asian	0.00445%	22,451
African / African-American	0.00267%	37,460
European (non-Finnish)	0.00263%	38,065
South Asian	0.0022%	45,537

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: ACTG1
Protein: p.Ser300=
Coding: c.900G>A
MANE Select: NM_001614
dbSNP: rs367966804
Type: single nucleotide variant
Location: chr17:81511011 (GRCh38)
Gene constraint: LOEUF 0.617 · pLI 0.46 (gnomAD)
Structure: AlphaFold pLDDT 95.44 · 11 PDB
Residue 300: a β-strand

Full ACTG1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

autosomal dominant nonsyndromic hearing loss 20 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: Baraitser-winter syndrome 2

Similar variants

ACTG1 p.Ser300Ala Uncertain significance ★ ⚠ same residue
ACTG1 p.Ala135Val Pathogenic/Likely pathogenic ★★ same condition
ACTG1 p.Ala204Gly Likely pathogenic ★★ same condition
ACTG1 p.Arg183Gln Pathogenic/Likely pathogenic ★★ same condition
ACTG1 p.Arg183Trp Pathogenic/Likely pathogenic ★★ same condition
ACTG1 p.Arg206Gln Pathogenic/Likely pathogenic ★★ same condition
ACTG1 p.Arg210Cys Pathogenic ★★ same condition
ACTG1 p.Arg254Trp Pathogenic/Likely 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/actg1-p-ser300 (accessed [today's date]).

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