[Molecular genetic study of congenital stationary night blindness]

Molecular genetic study was conducted on patients with fundus albipunctatus, incomplete and complete types of congenital stationary night blindness(CSNB), and Oguchi disease.

Mutations in the RDH5 gene were identified in all 10 patients with typical clinical features of fundus albipunctatus. Mutations in the gene were also detected in patients with fundus albipunctatus associated with cone dystrophy, and it was supposed that mutations of the gene cause progressive retinal dystrophy as well as fundus albipunctatus. Mutations in the CACNA1F gene were identified in all 15 patients with typical clinical features of incomplete CSNB. We found that some cases with incomplete CSNB were associated with retinal degeneration or optic atrophy with progressive impairment of vision. We detected mutations in the NYX gene in about half of the cases with complete CSNB. Molecular examination was useful to determine the exact hereditary pattern. We examined the arrestin gene and the rhodopsin kinase gene in 5 unrelated patients with Oguchi disease, and found arrestin gene mutations in 4 of them and a rhodopsin kinase gene mutation in the fifth patient.

We confirmed that fundus albipunctatus, incomplete CSNB, complete CSNB, and Oguchi disease were associated with mutations in the RDH5, CACNA1F, NYX, arrestin or rhodopsin kinase genes, respectively, in Japanese patients. Molecular analysis made it possible to diagnose patients with atypical phenotype and to obtain novel information about phenotypic variation.