The objective of this study was to describe the ophthalmic features and a novel mutation in the GRK1 (rhodopsin kinase) gene in 2 Japanese patients with Oguchi disease.
Normal deactivation kinetics in human L/M cones can occur without GRK7 when GRK1 is present in ESCS, but does not occur when GRK7 is present but GRK1 is deficient in Oguchi disease.
To date, three different mutations in the RK locus have been associated with Oguchi disease, an autosomal recessive form of stationary night blindness in man characterized in part by delayed photoreceptor recovery [Yamamoto, S. , Sippel, K. C., Berson, E. L. & Dryja, T. P. (1997) Nat.Genet.15, 175-178].
Our results indicate that null mutations in the rhodopsin kinase gene are a cause of Oguchi disease and extend the known genetic heterogeneity in congenital stationary night blindness.