Novel PRPF31 and PRPH2 mutations and co-occurrence of PRPF31 and RHO mutations in Chinese patients with retinitis pigmentosa

Objective: To screen mutations in the PRPF31, RHO, and PRPH2 genes in Chinese patients with retinitis pigmentosa (RP). Methods: Patients with RP were recruited from Retina Hong Kong. All the exons of the PRPF31, RHO, and PRPH2 genes were amplified and screened for mutations using single-stranded conformation polymorphism analysis followed by DNA sequencing. Frequencies of sequence changes were determined in patients and controls. Results: In 76 patients from 54 families, 3 pathogenic mutations and 32 nonpathogenic sequence changes were identified. One family with autosomal dominant RP was found to harbor a novel truncating PRPF31 mutation (p.Phe262SerfsX59) and a known missense RHO mutation (p.Pro347Leu), and 1 affected woman was heterozygous for both mutations. One simplex RP case was caused by a novel truncating PRPH2 mutation (p.Ala78LeufsX99). Thirteen of the 32 nonpathogenic sequence changes were novel and were found in low frequencies in patients with RP and controls. Conclusions: Mutations in PRPF31, RHO, and PRPH2 were found in low frequencies (1 of 9 autosomal dominant RP families) in Chinese patients, and the PRPF31 and PRPH2 truncating mutations were novel. Clinical Relevance: A search for a common cause for RP in Chinese patients is needed. The co-occurrence of 2 different gene mutations may modify the phenotype severity.