Two novel mutations of the retinitis pigmentosa GTPase regulator gene in two Chinese families with X-linked retinitis pigmentosa

Objective To detect mutations of the retinitis pigmentosa GTPase regulator (RPGR) gene in two Chinese X-linked retinitis pigmentosa families. Methods Fragments of exons 1-19 of the RPGR gene were amplified with intronic primers, u sing genomic DNA as template. The polymerase chain reaction (PCR) products wer e analysed by single-strand conformation polymorphism (SSCP) and direct sequenc ing. Mutations were identified by comparing DNA sequences of the patients with those of the normal controls.Results Two novel mutations, c1536delC and E332X, were identified in exons 12 and 9 of t he RPGR gene in both families. Each mutation was the first mutation found in th eir respective exons. Both mutations were predicted to cause premature terminat ion, which resulted in truncated proteins without normal functions of the RPGR p roducts.Conclusions Both mutations are the genetic basis of the pathogenesis in the respective famil ies. Our data might be helpful in analysing the function of the RPGR protein.