Is ACTA2 p.Val300= (c.900C>G) pathogenic?

ACTA2 p.Val300= (c.900C>G) is classified Likely benign in ACTA2 (ClinVar, Multiple submitters, 3 submitters; last evaluated 2024-10-31). Very rare (popmax 8.48e-05%, nfe); Associated with aortic aneurysm, familial thoracic 6.

What condition is associated with ACTA2 p.Val300= (c.900C>G)?

ACTA2 p.Val300= (c.900C>G) is associated with aortic aneurysm, familial thoracic 6, familial thoracic aortic aneurysm and aortic dissection (ClinVar).

How common is ACTA2 p.Val300= (c.900C>G) in the general population?

ACTA2 p.Val300= (c.900C>G) is very rare (popmax 8.48e-05%, nfe) (gnomAD).

ACTA2 p.Val300=

Q: How is Multisystemic smooth muscle dysfunction syndrome inherited?

Typically Unknown (Orphanet). A genetic counselor can assess individual risk for a family.

c.900C>G · rs2133246362 · VCV2973588

Likely benign Multiple submitters

Classification

Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

gnomAD v4.1

Rare

very rare (popmax 8.48e-05%, nfe)

Conditions

aortic aneurysm, familial thoracic 6

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 2.5	GERP 0.071, phastCons 1
Overall
CADD	7.198	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 8.48e-05% European (non-Finnish) · 1/1,179,934 alleles

Overall 6.84e-05% 1/1,461,784 alleles · very rare

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: ACTA2
Protein: p.Val300=
Coding: c.900C>G
MANE Select: NM_001613
dbSNP: rs2133246362
Type: single nucleotide variant
Location: chr10:88938151 (GRCh38)
Gene constraint: LOEUF 0.472 · pLI 0.99 · ClinGen HI 1/3 (gnomAD)
Structure: AlphaFold pLDDT 95.43

Full ACTA2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

aortic aneurysm, familial thoracic 6 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: familial thoracic aortic aneurysm and aortic dissection

For Multisystemic smooth muscle dysfunction syndrome (Orphanet):

Inheritance: Unknown
Onset: Infancy

Similar variants

ACTA2 p.Arg118Gln Pathogenic/Likely pathogenic ★★ same condition
ACTA2 p.Arg149Cys Pathogenic ★★ same condition
ACTA2 p.Arg149Leu Pathogenic/Likely pathogenic ★★ same condition
ACTA2 p.Arg179Cys Pathogenic ★★ same condition
ACTA2 p.Arg179His Pathogenic ★★ same condition
ACTA2 p.Arg198Cys Pathogenic/Likely pathogenic ★★ same condition
ACTA2 p.Arg198His Pathogenic/Likely pathogenic ★★ same condition
ACTA2 p.Arg256Cys 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/acta2-p-val300 (accessed [today's date]).

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