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Gene

GJA3

gap junction protein alpha 3

Summary

Cytogenetic location
13q12.11
Coordinates
Chromosome 13: 20,138,255–20,161,052 (GRCh38)
Exons
2 exons across 22.8 kb
Protein
435 amino acids
Also known as
CX46
Previous symbols
CZP3
MANE Select transcript
ENST00000241125.4NM_021954.4
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

  • Hereditary Congenital & Juvenile Cataract

    • Early-Onset Non-Syndromic Cataract

      Cataract that appears at birth or early in life without other features, caused by changes in lens genes such as the crystallins (CRYAA, CRYBB2, CRYGD and others), GJA3, GJA8 and MIP.

      • 3 GenCC submitters rate it definitive or strong
      What knowing changes

      Early detection and surgery in children help prevent permanent vision loss from amblyopia, and family members can be offered eye checks.

How GJA3 is laid out

  • Coding sequence
  • Untranslated region
  • Intron
  • Direction of transcription
  • Known disease-causing sites
  • Stretches short reads find hard
Chromosome 13, with a bracket where GJA3 sits. GJA3 and 8 genes near it on chromosome 13, from 19,649,654 to 20,649,653.Chromosome 1313q12.11p13p12p11.2p11.1q11q12.11q12.12q12.13q12.2q12.3q13.1q13.2q13.3q14.11q14.12q14.13q14.2q14.3q21.1q21.2q21.31q21.32q21.33q22.1q22.2q22.3q31.1q31.2q31.3q32.1q32.2q32.3q33.1q33.2q33.3q3419.8 Mb20 Mb20.2 Mb20.4 Mb20.6 MbPSPC1: 19,568,249–19,783,019, reverse strandPSPC1MPHOSPH8: 19,633,631–19,673,441, forward strandMPHOSPH8ZMYM5: 19,823,482–19,864,935, reverse strandZMYM5ZMYM2: 19,958,673–20,091,856, forward strandZMYM2GJA3: 20,138,255–20,161,052, reverse strandGJA3GJB2: 20,187,463–20,192,980, reverse strandGJB2GJB6: 20,221,962–20,232,450, reverse strandGJB6CRYL1: 20,403,666–20,525,893, reverse strandCRYL1IFT88: 20,566,600–20,691,697, forward strandIFT88Diagram of GJA3: 2 exons on the reverse strand of chromosome 13Exon 2: 38 known disease-causing sitesExon 2: 20,138,255–20,143,305, 5,051 basesExon 1: 20,160,890–20,161,052, 163 bases215′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 5.2 kb of the gene's 22.8 kb; 1,308 of those bases code for the protein.

How a genome test reads GJA3

38

positions in GJA3 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 22.8 kb of GJA3, introns included, not only the 5.2 kb of exons.

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.). GJA3 gene: gap junction protein alpha 3. Retrieved 17 October 2026, from https://dantelabs.com/genes/gja3

Vancouver

Dante Labs. GJA3 gene: gap junction protein alpha 3 [Internet]. [cited 17 October 2026]. Available from: https://dantelabs.com/genes/gja3

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