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GeneE
10 sources retrieved Β· Most recent: April 2026 Β· Index updated 14 days ago
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GJA3
gap junction protein alpha 3
Chromosome 13 Β· 13q12.11
NCBI Gene: 2700Ensembl: ENSG00000121743.5HGNC: HGNC:4277UniProt: Q9Y6H8
78PubMed Papers
21Diseases
0Drugs
39Pathogenic Variants
CLINICAL
OMIM Disease Gene
DATA QUALITY
βœ“ Experimental GO Evidenceβœ“ Swiss-Prot Reviewed
gap junction-mediated intercellular transportplasma membraneconnexin complexgap junction hemi-channel activityPosterior polar cataractearly-onset non-syndromic cataractDevelopmental cataractearly-onset nuclear cataract
✦AI Summary

GJA3 encodes connexin46 (Cx46), a structural component of lens fiber gap junctions that forms dodecameric intercellular channels 1. These gap junctions enable diffusion of small molecules and ions between adjacent lens cells, maintaining lens homeostasis and transparency 1. Cx46 is highly expressed in lens fiber cells alongside connexin50 2. GJA3 mutations cause autosomal dominant and recessive congenital cataracts with diverse phenotypes including posterior lenticonus, nuclear pulverulent, and central pulverulent types 3. Down-regulation of GJA3 is associated with hydrogen peroxide-induced lens epithelial cell apoptosis and age-related cataract development 4. Specific GJA3 variants carry elevated risks for secondary glaucoma and retinal detachment following cataract surgery 5. Computational screening identified 88 high-risk pathogenic GJA3 non-synonymous variants, with mutations affecting conserved sites, extracellular loops, and amino acid properties critical for protein stability 6. Frameshift and missense mutations disrupt connexin expression and function, causing progressive anterior nuclear cataracts in mouse models 7. Beyond lens biology, Cx46 localizes to cancer cell nuclei where it functions as a transcriptional regulator promoting oncogenic pathways 8, suggesting pleiotropic roles for GJA3-encoded protein beyond gap junction formation.

Sources cited
1
GJA3 is a structural component of lens fiber gap junctions forming dodecameric channels enabling ion and small molecule diffusion
PMID: 30044662
2
Cx46 (encoded by GJA3) is highly expressed in lens fiber cells and disrupted expression causes severe cataracts
PMID: 35223995
3
GJA3 mutations cause autosomal dominant and recessive congenital cataracts with diverse phenotypes including posterior lenticonus and central pulverulent cataracts
PMID: 38178039
4
Down-regulation of GJA3 is associated with H2O2-induced lens epithelial cell apoptosis and age-related cataract genesis
PMID: 28088522
5
GJA3 p.Asp67Tyr variant causes congenital cataracts with high risk for glaucoma following cataract surgery and retinal detachments
PMID: 37589989
6
88 high-risk pathogenic GJA3 non-synonymous variants identified through computational screening, affecting conserved sites and protein stability
PMID: 32143568
7
GJA3 frameshift mutations cause progressive anterior nuclear cataracts by reducing connexin protein levels
PMID: 25103261
8
Cx46 localizes to cancer cell nuclei and functions as a transcriptional regulator promoting oncogenic pathways
PMID: 40148950
Disease Associationsβ“˜21
Posterior polar cataractOpen Targets
0.83Strong
early-onset non-syndromic cataractOpen Targets
0.70Strong
Developmental cataractOpen Targets
0.49Moderate
early-onset nuclear cataractOpen Targets
0.40Weak
cataractOpen Targets
0.39Weak
pulverulent cataractOpen Targets
0.39Weak
early-onset posterior polar cataractOpen Targets
0.37Weak
Congenital cataracts - facial dysmorphism - neuropathyOpen Targets
0.34Weak
congenital cataracts-facial dysmorphism-neuropathy syndromeOpen Targets
0.34Weak
ulcerative colitisOpen Targets
0.32Weak
genetic disorderOpen Targets
0.19Weak
hearing lossOpen Targets
0.14Weak
Total congenital cataractOpen Targets
0.11Weak
Partial congenital cataractOpen Targets
0.11Weak
Cataract-microcornea syndromeOpen Targets
0.11Weak
early-onset zonular cataractOpen Targets
0.10Weak
Cataract with Y-shaped suture opacitiesOpen Targets
0.10Weak
hereditary hyperferritinemia with congenital cataractsOpen Targets
0.10Suggestive
isolated ectopia lentisOpen Targets
0.10Suggestive
Anterior polar cataractOpen Targets
0.09Suggestive
Cataract 14, multiple typesUniProt
Pathogenic Variants39
NM_021954.4(GJA3):c.226C>T (p.Arg76Cys)Pathogenic
Cataract 14 multiple types|not provided
β˜…β˜…β˜†β˜†2025β†’ Residue 76
NM_021954.4(GJA3):c.64G>A (p.Gly22Ser)Pathogenic
Cataract 14 multiple types
β˜…β˜…β˜†β˜†2025β†’ Residue 22
NM_021954.4(GJA3):c.184G>A (p.Glu62Lys)Pathogenic
Cataract 14 multiple types|not provided
β˜…β˜…β˜†β˜†2025β†’ Residue 62
NM_021954.4(GJA3):c.139G>A (p.Asp47Asn)Pathogenic
Cataract 14 multiple types|not provided
β˜…β˜…β˜†β˜†2025β†’ Residue 47
NM_021954.4(GJA3):c.176C>T (p.Pro59Leu)Pathogenic
Developmental cataract|Cataract 14 multiple types
β˜…β˜…β˜†β˜†2025β†’ Residue 59
NM_021954.4(GJA3):c.427G>A (p.Gly143Arg)Pathogenic
Cataract 14 multiple types
β˜…β˜…β˜†β˜†2024β†’ Residue 143
NM_021954.4(GJA3):c.7G>T (p.Asp3Tyr)Pathogenic
Cataract 14 multiple types
β˜…β˜…β˜†β˜†2023β†’ Residue 3
NM_021954.4(GJA3):c.151G>C (p.Asp51His)Likely pathogenic
Cataract 14 multiple types|not provided
β˜…β˜…β˜†β˜†2023β†’ Residue 51
NM_021954.4(GJA3):c.98G>T (p.Arg33Leu)Likely pathogenic
Cataract 14 multiple types
β˜…β˜…β˜†β˜†2023β†’ Residue 33
NM_021954.4(GJA3):c.56C>T (p.Thr19Met)Pathogenic
Developmental cataract|Congenital cataracts-facial dysmorphism-neuropathy syndrome|Cataract 14 multiple types
β˜…β˜…β˜†β˜†2023β†’ Residue 19
NM_021954.4(GJA3):c.130G>A (p.Val44Met)Pathogenic
Cataract 14 multiple types
β˜…β˜…β˜†β˜†2023β†’ Residue 44
NM_021954.4(GJA3):c.140A>G (p.Asp47Gly)Pathogenic
Cataract 14 multiple types
β˜…β˜†β˜†β˜†2025β†’ Residue 47
NM_021954.4(GJA3):c.1168_1175delinsCAGCAGTCTGGCAGGGGAGCGCCCTGGCAG (p.Thr390fs)Likely pathogenic
Cataract 14 multiple types
β˜…β˜†β˜†β˜†2025β†’ Residue 390
NM_021954.4(GJA3):c.113G>A (p.Gly38Glu)Likely pathogenic
Cataract 14 multiple types
β˜…β˜†β˜†β˜†2024β†’ Residue 38
NM_021954.4(GJA3):c.175C>G (p.Pro59Ala)Pathogenic
Cataract 14 multiple types
β˜…β˜†β˜†β˜†2024β†’ Residue 59
NM_021954.4(GJA3):c.176C>A (p.Pro59Gln)Likely pathogenic
not provided
β˜…β˜†β˜†β˜†2023β†’ Residue 59
NM_021954.4(GJA3):c.1152dup (p.Ser385fs)Likely pathogenic
Cataract 14 multiple types
β˜…β˜†β˜†β˜†2023β†’ Residue 385
NM_021954.4(GJA3):c.1197dup (p.Thr400fs)Likely pathogenic
Cataract 14 multiple types
β˜…β˜†β˜†β˜†2023β†’ Residue 400
NM_021954.4(GJA3):c.1137dup (p.Ser380fs)Pathogenic
Cataract 14 multiple types
β˜…β˜†β˜†β˜†2023β†’ Residue 380
NM_021954.4(GJA3):c.771dup (p.Ser258fs)Likely pathogenic
Cataract 14 multiple types
β˜…β˜†β˜†β˜†2023β†’ Residue 258
View on ClinVar β†—
Related Genes
GJA1Protein interaction97%TMEM114Protein interaction94%CRYGSProtein interaction92%GJB1Protein interaction91%GJD3Protein interaction91%MIPProtein interaction89%
Tissue Expression6 tissues
Heart
100%
Ovary
0%
Brain
0%
Lung
0%
Liver
0%
Bone Marrow
0%
Gene Interaction Network
Click a node to explore
GJA3GJA1TMEM114CRYGSGJB1GJD3MIP
PROTEIN STRUCTURE
Preparing viewer…
AlphaFoldAI-predicted Β· UniProt Q9Y6H8
View on AlphaFold β†—
Constraintβ“˜
LOEUFβ“˜
1.92LoF Tolerant
pLIβ“˜
0.13Tolerant
Observed/Expected LoF1.67 [0.33–1.92]
RankingsWhere GJA3 stands among ~20K protein-coding genes
  • #6,072of 20,598
    Most Researched78
  • #1,566of 5,498
    Most Pathogenic Variants39
  • #17,412of 17,882
    Most Constrained (LOEUF)1.92
Genes detectedGJA3
Sources retrieved10 papers
Response timeβ€”
πŸ“„ Sources
10β–Ό
1
Novel and known variants in GJA3 and LIM2 in congenital cataract families from North India.
PMID: 38178039
BMC Genomics Β· 2024
1.00
2
GJA3 Genetic Variation and Autosomal Dominant Congenital Cataracts and Glaucoma Following Cataract Surgery.
PMID: 37589989
JAMA Ophthalmol Β· 2023
0.90
3
Mutations of CX46/CX50 and Cataract Development.
PMID: 35223995
Front Mol Biosci Β· 2022
0.80
4
In silico analysis of non-synonymous single nucleotide polymorphisms (nsSNPs) in the human GJA3 gene associated with congenital cataract.
PMID: 32143568
BMC Mol Cell Biol Β· 2020
0.70
5
Down-regulation of GJA3 is associated with lens epithelial cell apoptosis and age-related cataract.
PMID: 28088522
Biochem Biophys Res Commun Β· 2017
0.60