Identification of a novel RPGR exon ORF15 mutation in a family with X-linked retinitis pigmentosa.

Objective: To investigate the phenotypic and genotypic characteristics of a novel mutation associated with X-linked retinitis pigmentosa (XLRP).

Methods: Six individuals in a family with XLRP were recruited, and clinical examinations were performed. All of the members were genotyped with microsatellite markers at loci that were considered to be associated with XLRP. The retinitis pigmentosa GTPase regulator gene (RPGR) was comprehensively screened using direct polymerase chain reaction sequencing.

Results: Genotyping analysis showed that the affected individuals in the family shared a common haplotype with selected markers. The patients demonstrated severe retinal degenerative phenotypes consistent with XLRP. Mutational screening of RPGR demonstrated a novel mutation, g.ORF15 + 1232_1233delGG.

Conclusions: We identified a novel mutation in the 3' end of a highly repetitive region of exon open reading frame 15 (ORF15) and documented the detailed phenotypes of the patients with XLRP with the mutation. The clinical phenotype was consistent with XLRP, supporting the observation that the mutations in the 3' end of the ORF15 coding sequence give rise to XLRP. Clinical Relevance The mutation in the 3' end of the ORF15 coding sequence can lead to a spectrum of phenotypes, and the cone-predominant phenotype-related mutations can be located irregularly in exon ORF15.