Positional cloning of the gene for X-linked retinitis pigmentosa 3: homology with the guanine-nucleotide-exchange factor RCC1

Hum Mol Genet. 1996 Jul;5(7):1035-41. doi: 10.1093/hmg/5.7.1035.


The gene for retinitis pigmentosa 3 (RP3), the most frequent form of X-linked RP (XLRP), has been mapped previously to a chromosome interval of less than 1000 kbp between the DXS1110 marker and the OTC locus at Xp21.1-p11.4. Employing a novel technique, YAC Representation Hybridization (YRH)', we have recently identified a small XLRP associated microdeletion in this interval, as well as several putative exons including the 3' end of a gene that was truncated by the deletion. cDNA library screening and sequencing of a cosmid centromeric to the deletion has now enabled us to identify numerous additional exons and to detect several point mutations in patients with XLRP. The predicted gene product shows homology to RCC1, the guanine-nucleotide-exchange factor (GEF) of the Ras-like GTPase Ran. Our findings suggest that we have cloned the long-sought RP3 gene, and that it may encode the GEF of a retina-specific GTP-binding protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Cell Cycle Proteins*
  • Cloning, Molecular
  • Cosmids
  • DNA, Complementary / genetics
  • DNA-Binding Proteins / genetics*
  • Exons / genetics
  • Eye Proteins*
  • Genes*
  • Genetic Linkage
  • Guanine Nucleotide Exchange Factors
  • Humans
  • Molecular Sequence Data
  • Nuclear Proteins*
  • Organ Specificity
  • Point Mutation / genetics
  • Polymorphism, Genetic
  • Proteins / genetics*
  • RNA, Messenger / analysis
  • Retinitis Pigmentosa / genetics*
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Sequence Homology, Nucleic Acid*
  • X Chromosome / genetics
  • ras Guanine Nucleotide Exchange Factors


  • Cell Cycle Proteins
  • DNA, Complementary
  • DNA-Binding Proteins
  • Eye Proteins
  • Guanine Nucleotide Exchange Factors
  • Nuclear Proteins
  • Proteins
  • RCC1 protein, human
  • RNA, Messenger
  • RPGR protein, human
  • ras Guanine Nucleotide Exchange Factors

Associated data

  • GENBANK/X97668