Two Novel ARG825X and 2336-2337delCT Mutations in the RP1 Gene in Japanese Families With Autosomal Dominant Retinitis Pigmentosa

Abstract

Abstract: : Purpose.To determine the clinical features of two Japanese families with autosomal dominant retinitis pigmentosa(ADRP) associated with two novel Arg825X and 2336-2337delCT in the RP1 gene. Methods. Mutation screening by direct sequence was performed on 120 unrelated patients with ADRP. The clinical features were characterized by visual acuity, slit-lamp biomicroscopy, electroretinography, fluorescein angiography, and kinetic visual field testing. Results. Molecular genetic analyses disclosed that two novel Arg825X and 2336-2337delCT mutations in the RP1 gene were identified in 6 patients from 2 unrelated families with ADRP. The ophthalmic findings showed typical retinitis pigemntosa and rapid progression over 40 years old. The 2336-2337delCT mutation resulted in a frame shift and a premature termination at codon 779, next codon from the deletion. Conclusion. We conclude that the mutation in the RP1 gene produces ADRP in Japanese population. The most common Arg677X mutation in the RP1 gene was not detected in our patients, instead we found two novel mutations. These findings suggested that the kinds and frequency of mutations in the RP1 gene depend on ethnic population.

Keywords: candidate gene analysis • mutations • retinal degenerations: hereditary