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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.