Novel Homozygous Missense Variant in GJA3 Connexin Domain Causing Congenital Nuclear and Cortical Cataracts

Int J Mol Sci. 2021 Dec 27;23(1):240. doi: 10.3390/ijms23010240.

Abstract

Congenital cataracts (CC) are responsible for approximately one-tenth of childhood blindness cases globally. Here, we report an African American family with a recessively inherited form of CC. The proband demonstrated decreased visual acuity and bilateral cataracts, with nuclear and cortical cataracts in the right and left eye, respectively. Exome sequencing revealed a novel homozygous variant (c.563A > G; p.(Asn188Ser)) in GJA3, which was predicted to be pathogenic by structural analysis. Dominantly inherited variants in GJA3 are known to cause numerous types of cataracts in various populations. Our study represents the second case of recessive GJA3 allele, and the first report in African Americans. These results validate GJA3 as a bona fide gene for recessively inherited CC in humans.

Keywords: African American; GJA3; congenital cataract; cortical cataract; exome sequencing; nuclear cataract.

Publication types

  • Case Reports

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Cataract / congenital*
  • Cataract / genetics*
  • Child
  • Connexins / chemistry*
  • Connexins / genetics*
  • Female
  • Homozygote
  • Humans
  • Mutation, Missense / genetics*
  • Protein Domains

Substances

  • Connexins
  • GJA3 protein, human