rs779757924

Variant names:

• chr10-88943870-G-A
• rs779757924
• NM_001613.4:c.296C>T

Your query was ambiguous. Multiple possible variants found:

• chr10-88943870-G-A
• chr10-88943870-G-C
• chr10-88943870-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_001613.4(ACTA2):​c.296C>T​(p.Ala99Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,732 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A99G) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: ACTA2 NM_001613.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 10.0
• Publications: 0 publications found

Genes affected

ACTA2 (HGNC:130): (actin alpha 2, smooth muscle) This gene encodes one of six different actin proteins. Actins are highly conserved proteins that are involved in cell motility, structure, integrity, and intercellular signaling. The encoded protein is a smooth muscle actin that is involved in vascular contractility and blood pressure homeostasis. Mutations in this gene cause a variety of vascular diseases, such as thoracic aortic disease, coronary artery disease, stroke, and Moyamoya disease, as well as multisystemic smooth muscle dysfunction syndrome. [provided by RefSeq, Sep 2017]

STAMBPL1 (HGNC:24105): (STAM binding protein like 1) Predicted to enable Lys63-specific deubiquitinase activity and thiol-dependent deubiquitinase. Predicted to be involved in protein K63-linked deubiquitination. Located in membrane. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the ACTA2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 27 curated pathogenic missense variants (we use a threshold of 10). The gene has 0 curated benign missense variants. Trascript score misZ: 4.6117 (above the threshold of 3.09). GenCC associations: The gene is linked to multisystemic smooth muscle dysfunction syndrome, connective tissue disorder, familial thoracic aortic aneurysm and aortic dissection, Moyamoya disease 5, aortic aneurysm, familial thoracic 6.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.852

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ACTA2	NM_001613.4	c.296C>T	p.Ala99Val	missense_variant	Exon 4 of 9	ENST00000224784.10	NP_001604.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ACTA2	ENST00000224784.10	c.296C>T	p.Ala99Val	missense_variant	Exon 4 of 9	1	NM_001613.4	ENSP00000224784.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461732 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727178

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26126

East Asian (EAS) AF: 0.00 AC: 0 AN: 39678

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53410

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1111908

Other (OTH) AF: 0.00 AC: 0 AN: 60392

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1

Jun 09, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.A99V variant (also known as c.296C>T), located in coding exon 3 of the ACTA2 gene, results from a C to T substitution at nucleotide position 296. The alanine at codon 99 is replaced by valine, an amino acid with similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.86
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.26
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.76	D;D;D
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;.;D
M_CAP	Pathogenic	0.43	D
MetaRNN	Pathogenic	0.85	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Benign	1.8	L;.;.
PhyloP100		10
PrimateAI	Pathogenic	0.86	D
PROVEAN	Uncertain	-2.4	N;D;D
REVEL	Pathogenic	0.75
Sift4G	Benign	0.11	T;.;.
Polyphen		1.0	D;.;.
Vest4		0.77
MutPred		0.63		Loss of disorder (P = 0.091);Loss of disorder (P = 0.091);Loss of disorder (P = 0.091);
MVP		0.90
ClinPred		0.96	D
GERP RS		5.9
Varity_R		0.87
gMVP		0.85
Mutation Taster		=22/78	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs779757924; hg19: chr10-90703627;