Sporadic and Familial Congenital Cataracts: Mutational Spectrum and New Diagnoses Using Next-Generation Sequencing

Hum Mutat. 2016 Apr;37(4):371-84. doi: 10.1002/humu.22948. Epub 2016 Jan 14.


Congenital cataracts are a significant cause of lifelong visual loss. They may be isolated or associated with microcornea, microphthalmia, anterior segment dysgenesis (ASD) and glaucoma, and there can be syndromic associations. Genetic diagnosis is challenging due to marked genetic heterogeneity. In this study, next-generation sequencing (NGS) of 32 cataract-associated genes was undertaken in 46 apparently nonsyndromic congenital cataract probands, around half sporadic and half familial cases. We identified pathogenic variants in 70% of cases, and over 68% of these were novel. In almost two-thirds (20/33) of these cases, this resulted in new information about the diagnosis and/or inheritance pattern. This included identification of: new syndromic diagnoses due to NHS or BCOR mutations; complex ocular phenotypes due to PAX6 mutations; de novo autosomal-dominant or X-linked mutations in sporadic cases; and mutations in two separate cataract genes in one family. Variants were found in the crystallin and gap junction genes, including the first report of severe microphthalmia and sclerocornea associated with a novel GJA8 mutation. Mutations were also found in rarely reported genes including MAF, VIM, MIP, and BFSP1. Targeted NGS in presumed nonsyndromic congenital cataract patients provided significant diagnostic information in both familial and sporadic cases.

Keywords: congenital cataract; eye; microcornea; microphthalmia; next-generation sequencing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Cataract / diagnosis*
  • Cataract / genetics*
  • Child
  • Child, Preschool
  • Computational Biology / methods
  • Connexins / genetics
  • Crystallins / genetics
  • DNA Mutational Analysis
  • Exome
  • Female
  • Genes, X-Linked
  • Genetic Association Studies*
  • High-Throughput Nucleotide Sequencing*
  • Humans
  • Inheritance Patterns
  • Male
  • Membrane Proteins
  • Mutation*
  • Nuclear Proteins / genetics
  • PAX6 Transcription Factor / genetics
  • Pedigree
  • Phenotype
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins c-maf / genetics
  • Repressor Proteins / genetics


  • BCOR protein, human
  • Connexins
  • Crystallins
  • MAF protein, human
  • Membrane Proteins
  • NHS protein, human
  • Nuclear Proteins
  • PAX6 Transcription Factor
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-maf
  • Repressor Proteins
  • GJA3 protein, human
  • connexin 50