Screening of Candidate Genes on Japanese Retinal Dystrophies

Abstract

Since the causative genes for retinal dystrophies were recently clarified and genetic defects were reported, we could screen the candidate genes in patients with retinal dystrophies. However, we have to check many candidate genes because most of the retinal dystrophies correlate with the various gene defects. Rhodopsin and perpherin/RDS genes of Japanese 70 retinitis pigmentosa and 80 atypical retinitis pigmentosa patients were screened using restriction enzyme, dot blot hybridization and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). Three point mutations in the rhodopsin gene were detected. No peripherin/RDS gene defect was detected. We established and evaluated the SSCP condition using a gyrate atrophy family and four choroideremia families. The direct sequence analyses confirmed the accuracy of our PCR-SSCP analyses. Our investigation revealed that PCR-SSCP analysis was good procedure if the best condition for differentiating bands was determined. Further screening of the candidate genes using the improved PCR-SSCP procedure in Japanese retinal dytrophies is now on going.