Connexin 50 mutation in a family with congenital "zonular nuclear" pulverulent cataract of Pakistani origin

Hum Genet. 1999 Jul-Aug;105(1-2):168-70. doi: 10.1007/s004399900094.


Inherited cataract is a clinically and genetically heterogeneous disease that most often presents as a congenital autosomal dominant trait. Here we report linkage of a three-generation family of Pakistani origin with autosomal dominant cataract "zonular nuclear" pulverulent type (CZNP) on chromosome 1q21.1. Genome wide-linkage analysis excluded all the known cataract loci except on chromosome 1q. Significantly positive 2-point lod score values (Z=3.01 at theta=0) were obtained for markers D1S305 and D1S2721, which are known to flank the gene for connexin 50 (Cx50) or gap junction protein alpha-8 (Gja8). Previously a mutation in this gene has been reported in a British family with zonular pulverulent cataract (CZP). Here we describe a second mutation (E48K) in connexin 50 that confirms the involvement of this gene in cataractogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cataract / congenital*
  • Cataract / genetics*
  • Connexins
  • Eye Proteins / genetics*
  • Eye Proteins / physiology
  • Female
  • Genetic Markers
  • Humans
  • Male
  • Models, Biological
  • Mutation, Missense*
  • Pakistan
  • Phenotype


  • Connexins
  • Eye Proteins
  • Genetic Markers
  • connexin 50