Rhodopsin mutations are scarcely implicated in autosomal recessive retinitis pigmentosa: A preliminary study of Egyptian retinitis pigmentosa patients

Background: Retinitis pigmentosa (RP) is a clinically and genetically heterogeneous group of inherited retinal degenerations that is estimated to affect more than 1.5 million people worldwide. RP is characterized by retinal pigment deposits visible on fundus examination, abnormal electroretinogram and progressive retinal dysfunction. Aim: The present work aimed to identify the possible mutations in the rhodopsin gene (RHO) among Egyptian RP patients as well as identifying the different inheritance patterns of those patients. Subjects and methods: Thirty diagnosed retinitis pigmentosa patients were enrolled in the study. Inheritance forms of RP were identified by recording full family history, the coding regions of the rhodopsin gene were sequenced using blood-derived genomic DNA samples donated by patients and fifteen healthy controls. Results: A high percentage of autosomal recessive cases was reported. Also a high parental consanguinity rates were evident. Sequencing of rhodopsin gene revealed no mutations among the study population. Conclusion: Rhodopsin mutations are scarcely associated with the autosomal recessive RP, suggesting that wide scale studies are needed to determine the genetic variations involved in RP and particularly in the autosomal recessive inheritance.