CNGB3 mutations account for 50% of all cases with autosomal recessive achromatopsia

Eur J Hum Genet. 2005 Mar;13(3):302-8. doi: 10.1038/sj.ejhg.5201269.


Achromatopsia is a congenital, autosomal recessively inherited disorder characterized by a lack of color discrimination, low visual acuity (<0.2), photophobia, and nystagmus. Mutations in the genes for CNGA3, CNGB3, and GNAT2 have been associated with this disorder. Here, we analyzed the spectrum and prevalence of CNGB3 gene mutations in a cohort of 341 independent patients with achromatopsia. In 163 patients, CNGB3 mutations could be identified. A total of 105 achromats carried apparent homozygous mutations, 44 were compound (double) heterozygotes, and 14 patients had only a single mutant allele. The derived CNGB3 mutation spectrum comprises 28 different mutations including 12 nonsense mutations, eight insertions and/or deletions, five putative splice site mutations, and three missense mutations. Thus, the majority of mutations in the CNGB3 gene result in significantly altered and/or truncated polypeptides. Several mutations were found recurrently, in particular a 1 bp deletion, c.1148delC, which accounts for over 70% of all CNGB3 mutant alleles. In conclusion, mutations in the CNGB3 gene are responsible for approximately 50% of all patients with achromatopsia. This indicates that the CNGB3/ACHM3 locus on chromosome 8q21 is the major locus for achromatopsia in patients of European origin or descent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Animals
  • Color Vision Defects / genetics*
  • Color Vision Defects / physiopathology
  • Color Vision Defects / veterinary
  • Cyclic Nucleotide-Gated Cation Channels
  • Dog Diseases / genetics
  • Dogs
  • Genes, Recessive*
  • Humans
  • Ion Channels / genetics*
  • Mutation*
  • Phenotype
  • Retinal Cone Photoreceptor Cells


  • CNGB3 protein, human
  • Cyclic Nucleotide-Gated Cation Channels
  • Ion Channels