Expanding the phenotype of CRYAA nucleotide variants to a complex presentation of anterior segment dysgenesis

Orphanet J Rare Dis. 2020 Aug 13;15(1):207. doi: 10.1186/s13023-020-01484-8.

Abstract

Background: Mutations in CRYAA, which encodes the α-crystallin protein, are associated with a spectrum of congenital cataract-microcornea syndromes.

Results: In this study, we performed clinical examination and subsequent genetic analysis in two unrelated sporadic cases of different geographical origins presenting with a complex phenotype of ocular malformation. Both cases manifested bilateral microphthalmia and severe anterior segment dysgenesis, primarily characterized by congenital aphakia, microcornea, and iris hypoplasia/aniridia. NGS-based analysis revealed two novel single nucleotide variants occurring de novo and affecting the translation termination codon of the CRYAA gene, c.520T > C and c.521A > C. Both variants are predicted to elongate the C-terminal protein domain by one-third of the original length.

Conclusions: Our report not only expands the mutational spectrum of CRYAA but also identifies the genetic cause of the unusual ocular phenotype described in this report.

Keywords: Aniridia; Anterior segment dysgenesis; CRYAA; Congenital aphakia; Microcornea; Microphthalmia; NGS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cataract*
  • Crystallins* / genetics
  • Eye Abnormalities* / genetics
  • Humans
  • Mutation / genetics
  • Nucleotides
  • Pedigree
  • Phenotype

Substances

  • CRYAA protein, human
  • Crystallins
  • Nucleotides