Purpose: To investigate the causative genes of inherited retinal diseases diagnosed at a single facility.
Subjects and methods: The study population comprised 285 families diagnosed with inherited retinal diseases and who underwent genetic analysis at the Department of Ophthalmology, Nagoya University Hospital. Genetic analysis was performed using next-generation sequencing, whereas analyses of the RDH5 and BEST1 genes in some families were performed using Sanger sequencing.
Results: The causative gene was confirmed in 121 (42%) of the 285 families. In particular, the causative gene could be confirmed in 59 (37%) of the 160 families with retinitis pigmentosa. The most common causative gene was EYS (21 families), followed by RP1 (9 families) and USH2A (7 families). PRPF31 was the most common causative gene for the autosomal dominant families, and RPGR was the most common causative gene for the X-linked recessive families. In addition to retinitis pigmentosa, BEST1 mutations were noted in 15 of the 16 families diagnosed with vitelliform macular dystrophy or autosomal recessive bestrophinopathy, CYP4V2 mutations were noted in 8 of the 9 families diagnosed with crystalline retinopathy, and RP1 L1 mutations were noted in all the 6 families diagnosed with occult macular dystrophy. Ocular findings were used to identify the causative gene in 15 (28%) of the 54 other families with macular dystrophy, cone dystrophy, and cone-rod dystrophy, in whom it was difficult to estimate the causative gene.
Conclusions: Our results showed that the causative gene can often be identified in diseases in which the causative gene can be inferred based on clinical diagnosis. We were also able to identify the causative gene in approximately 30% of families with diseases such as retinitis pigmentosa, macular dystrophy, and cone-rod dystrophy that have multiple causative genes, thus suggesting the utility of next-generation sequencing.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 124: 687-696, 2020.