A photoreceptor gene mutation in an indigenous black African family with retinitis pigmentosa identified using a rapid screening approach for common rhodopsin mutations

Hereditary retinal degenerations may be subdivided into those affecting pre dominantly the central (macular) or peripheral regions of the retina. Retin itis pigmentosa (RP) affects the photoreceptors; death of the rod cells is followed by a progressive loss of cone cells, resulting in relatively early loss of peripheral vision and progressive constriction of the visual field s. A mutation in the gene encoding the photoreceptor protein, rhodopsin, wa s the first molecular defect identified as a potential cause of inherited r etinal degeneration (RD). In the study reported here, simple tests for rhod opsin involvement in 194 southern African patients with a history of retina l degeneration, including 14 black African patients, were performed. Two RP patients were identified with disease-causing mutations in the rhodopsin g ene: one from a black African family in which a codon 347 mutation resulted in a Pro-Leu substitution, and one in a family of Caucasian origin where a codon 58 alteration resulted in a Thr-Arg substitution. This is the first report of a disease-causing rhodopsin mutation in an indigenous black Afric an family with retinitis pigmentosa.