Three novel mutations causing a truncated protein within the RP2 gene in Italian families with X-linked retinitis pigmentosa

Mutat Res. 2001 Jan;432(3-4):79-82. doi: 10.1016/s1383-5726(00)00007-8.

Abstract

X-linked retinitis pigmentosa (XLRP) results from mutations in a number of loci, including RP2 at Xp11.3, and RP3 at Xp21.1. RP2 and RP3 genes have been identified by positional cloning. RP2 mutations are found in about 10% of XLRP patients. We performed a mutational screening of RP2 gene inpatients belonging to seven unrelated families in linkage with the RP2 locus. SSCP analysis detected three conformation variants, within exon 2 and 3. Direct sequencing of exon 2, disclosed a G-->A transition at nucleotide 449 (W150X), and a G-->T transversion in position 547 (E183X). Sequence analysis of exon 3 variant revealed an insertion (853/854insG), leading to a frameshift. In this patient, we detected an additional sequence alteration (A-->G at nucleotide 848, E283G). Each mutation was co-segregating with the disease in the affected family members available for the study. These mutations are expected to introduce a stop codon within the RP2 coding sequence probably resulting in a truncated or unstable protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Codon, Terminator / genetics
  • Exons
  • Eye Proteins*
  • Female
  • Frameshift Mutation
  • GTP-Binding Proteins
  • Genetic Linkage
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Italy
  • Male
  • Membrane Proteins
  • Mutation*
  • Point Mutation
  • Proteins / genetics*
  • Retinitis Pigmentosa / genetics*
  • X Chromosome / genetics*

Substances

  • Codon, Terminator
  • Eye Proteins
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • Proteins
  • RP2 protein, human
  • GTP-Binding Proteins