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Genetics Library / Genes / ACTA2

GENE REFERENCE / HGNC:130

ACTA2

actin alpha 2, smooth muscle

protein-coding gene10q23.31Gene information

What does this gene do?

The ACTA2 gene provides instructions for making a protein called smooth muscle alpha (α)-2 actin, which is part of the actin protein family. Actin proteins are important for cell movement and the tensing (contraction) of muscles.

Smooth muscle α-2 actin is found in smooth muscle cells. Smooth muscles line the internal organs, including the blood vessels, stomach, and intestines. Within smooth muscle cells, smooth muscle α-2 actin forms the core of structures called sarcomeres, which are necessary for muscles to contract. Smooth muscles contract and relax as part of their normal function without being consciously controlled.

Layers of smooth muscle cells are found in the walls of the arteries, which are blood vessels that carry blood from the heart to the rest of the body. Smooth muscle α-2 actin contributes to the ability of these muscles to contract, which allows the arteries to maintain their shape instead of stretching out as blood is pumped through them.

Source: MedlinePlus, National Library of Medicine. Source publication: 2022-07-01. Source review: 2015-01.

Related condition topics

MedlinePlus mentions this gene in the condition pages below. These links alone do not show that the gene causes a condition.

ClinGen reviews

ClinGen reviews the evidence linking a particular gene to a condition. Each rating below describes the strength of that link. It does not classify a variant in your DNA file.

ConditionInheritanceEvidence
multisystemic smooth muscle dysfunction syndromeMONDO:0013452 · Evaluated 2025-01-24Autosomal dominantDefinitiveHereditary Cardiovascular Disease Gene Curation Expert Panel

ClinVar records

These numbers show what has been submitted to ClinVar. They cannot tell you how likely you are to have a condition.

Submitted alleles
800
Submissions for variants in or overlapping this gene
1,629
Submissions explicitly reporting this gene
1,549
Alleles reported pathogenic / likely pathogenic
51
VariationIDs with uncertain significance
379
VariationIDs with conflicting classifications
40

The rows count different things: alleles, submissions or VariationIDs. Their categories can overlap, so do not add them together. Pathogenic/likely pathogenic counts exclude structural variants that merely overlap a gene. A dash in the source means “not reported,” not zero.

NCBI produces the gene-summary file each week using counts recorded at the start of the month. The numbers may differ from those on the live ClinVar website. Read the field definitions ↗

View this gene in ClinVar ↗

YOUR DNA FILE

Can your DNA file tell you about ACTA2?

From a DNA test kit (such as 23andMe, AncestryDNA or MyHeritage). These kits check a fixed list of about 600,000 to 700,000 positions across your whole genome. ClinVar lists 51 alleles in ACTA2 reported as pathogenic or likely pathogenic. A kit checks only some of these positions, and often none of them.

From whole genome sequencing (a VCF file). Sequencing reads most of your genome. Your file lists the places where your DNA differs from the reference genome. Some regions are hard to sequence, including parts of some genes that have near-identical copies elsewhere, and a VCF file does not record which positions were read well.

If a variant is not in your file, that does not mean you don’t have it.

What BioDecode checks

BioDecode compares every variant in your file with ClinVar, on your own computer. For each match, it shows the ClinVar classification, the review status and the condition it was reported for. Your file is not uploaded.

A ClinVar classification applies to one particular variant and the condition it was reported for. It does not tell you about other variants in ACTA2.

BioDecode cannot fill gaps in your test, diagnose a condition or replace clinical testing.

Sources and dates

The source information on this page last changed on 2026-10-17.

HGNC Source details

Open source record ↗

Source release: Fri, 16 Oct 2026 13:36:12 GMT
Source record updated: 2023-01-20

SHA-256: 72bfe0c05800163c040a2cf663c70501f9ac9236469fbd0b552f2cd37a4d7f67

MedlinePlus Source details

Open source record ↗

Source release: Sat, 17 Oct 2026 05:15:49 GMT
Source publication: 2022-07-01
Source review: 2015-01

SHA-256: fdc8bd614310c12718379cef6569962e5d0e791cecabcc355b53a72816ac263a

ClinVar Source details

Open source record ↗

Source release: Sun, 11 Oct 2026 06:36:01 GMT

SHA-256: b21584f8ebc89a636ce9706023fa9052460587e2ab0fe6d0edf4b9db34336c02

ClinGen Source details

Open source record ↗

Source release: Sat, 17 Oct 2026 07:46:29 GMT

SHA-256: 46d4c75fcae7dd62a9dea4988bbbd440bdc68f2db452fea1556d47b0406de60e

About the library sources · Latest validated release · Record 9ce3a3139fa7