An analysis of ABCR mutations in British patients with recessive retinal dystrophies

Invest Ophthalmol Vis Sci. 2000 Jan;41(1):16-9.

Abstract

Purpose: Several reports have shown that mutations in the ABCR gene can lead to Stargardt disease (STGD)/fundus flavimaculatus (FFM), autosomal recessive retinitis pigmentosa (arRP), and autosomal recessive cone-rod dystrophy (arCRD). To assess the involvement of ABCR in these retinal dystrophies, the gene was screened in a panel of 70 patients of British origin.

Methods: Fifty-six patients exhibiting the STGD/FFM phenotype, 6 with arRP, and 8 with arCRD, were screened for mutations in the 50 exons of the ABCR gene by heteroduplex analysis and direct sequencing. Microsatellite marker haplotyping was used to determine ancestry.

Results: In the 70 patients analyzed, 31 sequence changes were identified, of which 20 were considered to be novel mutations, in a variety of phenotypes. An identical haplotype was associated with the same pair of in-cis alterations in 5 seemingly unrelated patients and their affected siblings with STGD/FFM. Four of the aforementioned patients were found to carry three alterations in the coding sequence of the ABCR gene, with two of them being in-cis.

Conclusions: These results suggest that ABCR is a relatively polymorphic gene. Because putative mutations have been identified thus far only in 25 of 70 patients, of whom only 8 are compound heterozygotes, a large number of mutations have yet to be ascertained. The disease haplotype seen in the 5 patients carrying the same "complex" allele is consistent with the presence of a common ancestor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters / genetics*
  • DNA / analysis
  • Electroretinography
  • Haplotypes
  • Heteroduplex Analysis
  • Humans
  • Point Mutation*
  • Polymerase Chain Reaction
  • Retinal Degeneration / genetics*
  • Retinal Degeneration / pathology
  • Rod Cell Outer Segment / pathology*
  • Sequence Analysis, DNA
  • United Kingdom

Substances

  • ABCA4 protein, human
  • ATP-Binding Cassette Transporters
  • DNA