Oguchi is a rare genetic disorder with night blindness first reported in Japan. Patients show no or reduced rod function and normal cone function.
Inheritance: autosomal recessive
Chromosomes and genes:
(1) 2q37.1: S-antigen visual arrestin (SAG)
(2) 13q34: G protein-coupled receptor kinase 1 (GRK1)
Clinical features:
(1) congenital stationary night blindness
(2) normal color vision and visual acuity
(3) Mizuo-Nakamura phenomenon (reversible change in fundus color from gold leaf-like reflex to normal after full dark adaptation)
(4) characteristic electroretinogram changes (un-recordable rod response; reductions in maximal response, oscillatory potentials and flicker response)
