The protein is a cytoplasmic actin that maintains the cytoskeleton and mediates internal cell motility in all cell types. Mutations cause autosomal dominant Baraitser-Winter syndrome 2 and autosomal dominant nonsyndromic sensorineural progressive hearing loss (DFNA20/26). The pathogenic mechanism involves dominant-negative effects of the mutant protein.

OMIMResearchSummary from RefSeq, OMIM, UniProt, Mechanism
GOFmechanismADLOEUF 0.862 OMIM phenotypes
Clinical SummaryACTG1
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Gene-Disease Validity (ClinGen)
Baraitser-winter syndrome 2 · ADDefinitive

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.
Some data sources returned errors (1)

ncbi: Error: NCBI fetch failed: 429 https://eutils.ncbi.nlm.nih.gov/entrez/eutils/esearch.fcgi

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Missense constrained — critical functional residues
LoF Constraint
0.86LOEUF
pLI 0.005
Z-score 1.95
OE 0.43 (0.240.86)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
3.16Z-score
OE missense 0.37 (0.300.45)
72 obs / 196.7 exp
Constrained

Highly missense-constrained (top ~0.1%)

Observed / Expected Ratios
LoF OE0.43 (0.240.86)
00.351.4
Missense OE0.37 (0.300.45)
00.61.4
Synonymous OE3.73
01.21.6
LoF obs/exp: 6 / 13.8Missense obs/exp: 72 / 196.7Syn Z: -18.97
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveACTG1-related Baraitser-Winter syndromeGOFAD
limitedACTG1-related isolated ocular colobomaOTHERAD
DN
0.7034th %ile
GOF
0.5366th %ile
LOF
0.3164th %ile

This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative and gain-of-function). Both the Badonyi & Marsh prediction and the broader genomic evidence point to dominant-negative as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

DNprediction above median
GOF1 literature citation

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

GOFBaraitser-Winter, Fryns-Aftimos and cerebrofrontofacial syndrome types 1 and 3 have recently been associated with heterozygous gain-of-function mutations in one of the two ubiquitous cytoplasmic actin-encoding genes ACTB and ACTG1 that encode beta- and gamma-actins.PMID:25052316

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

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

ACTG1 · 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.

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Clinical Literature
Open Research Assistant →
Key Publications
Landmark & review papers · by relevance
PubMed
Top 5 results · since 2015Search PubMed ↗