OBJECTIVETo detect mutations of the retinitis pigmentosa GTPase regulator (RPGR) gene in two Chinese X-linked retinitis pigmentosa families.

METHODSFragments of exons 1-19 of the RPGR gene were amplified with intronic primers, using genomic DNA as template. The polymerase chain reaction (PCR) products were analysed by single-strand conformation polymorphism (SSCP) and direct sequencing. Mutations were identified by comparing DNA sequences of the patients with those of the normal controls.

RESULTSTwo novel mutations, c1536delC and E332X, were identified in exons 12 and 9 of the RPGR gene in both families. Each mutation was the first mutation found in their respective exons. Both mutations were predicted to cause premature termination, which resulted in truncated proteins without normal functions of the RPGR products.

CONCLUSIONSBoth mutations are the genetic basis of the pathogenesis in the respective families. Our data might be helpful in analysing the function of the RPGR protein.

Carrier Proteins ; genetics ; Eye Proteins ; Female ; Genetic Linkage ; Humans ; Male ; Mutation ; Polymerase Chain Reaction ; Polymorphism, Single-Stranded Conformational ; Retinitis Pigmentosa ; genetics ; Sequence Analysis, DNA ; X Chromosome