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Gene

ACTA1

actin alpha 1, skeletal muscle

Summary

Cytogenetic location
1q42.13
Coordinates
Chromosome 1: 229,431,245–229,434,094 (GRCh38)
Exons
7 exons across 2.9 kb
Protein
377 amino acids
Also known as
NEM3
Previous symbols
ACTA
MANE Select transcript
ENST00000366684.7NM_001100.4
Locus type
gene with protein product
  • Very high
  • Confident
  • Low
  • Very low

Reference genomeGRCh38

Positions on gene and variant pages follow this choice, in this browser.

Curated report relevant to this gene

  • Congenital Myopathies

    • ACTA1-related myopathy (alpha-actinopathy)

      A spectrum of congenital and adult-onset myopathies caused by variants in the skeletal muscle alpha-actin gene, ACTA1, with weakness, low muscle tone and breathing difficulties.

      • ClinGen rates the link definitive
      • 6 GenCC submitters rate it definitive or strong
    • Nemaline myopathy

      A congenital myopathy defined by rod-shaped structures in muscle fibers, most often caused by NEB or ACTA1 variants.

      • 4 GenCC submitters rate it definitive or strong

How ACTA1 is laid out

  • Coding sequence
  • Untranslated region
  • Intron
  • Direction of transcription
  • Known disease-causing sites
  • Variants with a page
Chromosome 1, with a bracket where ACTA1 sits. ACTA1 and 6 genes near it on chromosome 1, from 228,932,670 to 229,932,669.Chromosome 11q42.13p36.33p36.32p36.31p36.23p36.22p36.21p36.13p36.12p36.11p35.3p35.2p35.1p34.3p34.2p34.1p33p32.3p32.2p32.1p31.3p31.2p31.1p22.3p22.2p22.1p21.3p21.2p21.1p13.3p13.2p13.1p12p11.2p11.1q11q12q21.1q21.2q21.3q22q23.1q23.2q23.3q24.1q24.2q24.3q25.1q25.2q25.3q31.1q31.2q31.3q32.1q32.2q32.3q41q42.11q42.12q42.13q42.2q42.3q43q44229 Mb229.2 Mb229.4 Mb229.6 Mb229.8 MbRAB4A: 229,271,062–229,307,213, forward strandRAB4ACCSAP: 229,321,011–229,343,294, reverse strandCCSAPACTA1: 229,431,245–229,434,094, reverse strandACTA1NUP133: 229,439,673–229,508,376, reverse strandNUP133ABCB10: 229,516,582–229,559,034, reverse strandABCB10TAF5L: 229,593,111–229,626,134, reverse strandTAF5LURB2: 229,625,855–229,661,709, forward strandURB2Diagram of ACTA1: 7 exons on the reverse strand of chromosome 1Exon 7: 18 known disease-causing sitesExon 6: 19 known disease-causing sitesExon 5: 26 known disease-causing sitesExon 4: 25 known disease-causing sitesExon 3: 58 known disease-causing sitesExon 2: 14 known disease-causing sitesExon 7: 229,431,245–229,431,642, 398 bases. 12 variants with a page in exon 7. List themExon 6: 229,431,721–229,431,902, 182 bases. 2 variants with a page in exon 6. List themExon 5: 229,431,994–229,432,185, 192 bases. 7 variants with a page in exon 5. List themExon 4: 229,432,270–229,432,431, 162 bases. 2 variants with a page in exon 4. List themExon 3: 229,432,556–229,432,880, 325 bases. 10 variants with a page in exon 3. List themExon 2: 229,432,987–229,433,127, 141 bases. 4 variants with a page in exon 2. List themExon 1: 229,434,004–229,434,094, 91 bases76543215′3′

Exons of the gene's MANE Select transcript (release v1.5), from NCBI and EMBL-EBI, on the GRCh38 reference genome.

Chromosome bands from UCSC's GRCh38 ideogram (2022-10-29).

Nearby genes from Ensembl release 116, on GRCh38.

Exons make up 1.5 kb of the gene's 2.9 kb; 1,134 of those bases code for the protein.

How a genome test reads ACTA1

166

positions in ACTA1 where ClinVar classes a change as pathogenic or likely pathogenic

None of them falls in a region short reads find hard.

A whole genome covers all 2.9 kb of ACTA1, introns included, not only the 1.5 kb of exons.

Variants with a page (39)

The ACTA1 variants with a page here, most review stars first. Each page describes ClinVar's public record of the variant, never a result.

VariantHGVS c.Exon or intronPosition (GRCh38)ClinVar classificationReview status
c.617-5C>AIntron 4229,432,190Likely pathogenic3 stars out of 4 reviewed by expert panel
c.687G>CExon 5229,432,115Pathogenic3 stars out of 4 reviewed by expert panel
c.990+1G>TIntron 6229,431,720Pathogenic3 stars out of 4 reviewed by expert panel
C376Fc.1127G>TExon 7229,431,506Likely pathogenic3 stars out of 4 reviewed by expert panel
C376Sc.1127G>CExon 7229,431,506Pathogenic3 stars out of 4 reviewed by expert panel
D13Ec.39C>AExon 2229,433,077Likely pathogenic3 stars out of 4 reviewed by expert panel
D13Nc.37G>AExon 2229,433,079Likely pathogenic3 stars out of 4 reviewed by expert panel
D58Nc.172G>AExon 3229,432,838Likely pathogenic3 stars out of 4 reviewed by expert panel
D181Tfs*11c.541delExon 4229,432,344Pathogenic3 stars out of 4 reviewed by expert panel
D290Hc.868G>CExon 6229,431,843Pathogenic3 stars out of 4 reviewed by expert panel

See all 39 ACTA1 variants →

Where this comes from

  • HGNC: the gene's symbol, name, other symbols and location.
  • MANE Select v1.5, from NCBI and EMBL-EBI: the transcript, its exons and coding sequence.
  • GenCC and ClinGen, released 2026-10-16: which conditions the gene is linked to, and how strongly.
  • The ACMG secondary findings list, SF v3.2.
  • ClinVar and the GIAB stratifications: known disease-causing sites, and the regions short reads find hard.
  • The Human Phenotype Ontology, release 2026-09-01: the traits linked to the gene. Find out more at hpo.jax.org.
  • Data release 2026.10.16-c6eea6bf.

Cite this page

APA

Dante Labs. (n.d.). ACTA1 gene: actin alpha 1, skeletal muscle. Retrieved 17 October 2026, from https://dantelabs.com/genes/acta1

Vancouver

Dante Labs. ACTA1 gene: actin alpha 1, skeletal muscle [Internet]. [cited 17 October 2026]. Available from: https://dantelabs.com/genes/acta1

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