[A molecular biological study on retinitis pigmentosa].

Retinitis pigmentosa was investigated with molecular genetic techniques, to identify gene abnormalities and to obtain a better understanding of the mechanism of retinal degeneration. First, a search for candidate genes was performed focusing on rhodopsin, peripherin/RDS, and phosducin genes, using non-radioisotopic SSCP and genomic DNA samples obtained from 387 Japanese patients with retinitis pigmentosa, including 56 families of the autosomal dominant type (ADRP). One ADRP family with rhodopsin Pro-347-Leu mutation and another with peripherin/RDS Asn-244-Lys mutation were identified. The genotype and phenotype correlation of each ADRP family was then analysed. Ocular findings associated with the rhodopsin Pro-347-Leu in the Japanese family were similar to those reported in Caucasian families, indicating that the same mutation can produce the common phenotype even among different ethnic populations. The phenotype associated with the peripherin/RDS Asn-244-Lys showed typical findings of retinitis pigmentosa associated with bull's-eye maculopathy. Finally, glutamate was immunohistochemically quantified in the photoreceptor inner segment of rds/rds mice using anti-Glu antibody. The results showed that glutamate was accumulated in the rds/rds mouse photoreceptor inner segment, suggesting that glutamate may play a role in the process of retinal degeneration caused by the peripherin/RDS gene abnormality, although the precise mechanism is currently unknown.