Oguchi disease: phenotypic characteristics of patients with the frequent 1147delA mutation in the arrestin gene.

To characterize clinical features of patients with Oguchi disease associated with a homozygous deletion of ad~ nine at nucleotide 1147 (1147delA) in codon 309 in the arrestin gene. Mutation screening by singlestrand conformation polymorphism analysis was done, followed by sequencing. Ophthalmologic testing included evaluation of visual acuity and color vision, fundus examination, electroretinography, fluorescein angiography, evaluation of kinetic visual field, and dark adaptometry. Nine patients with Oguchi disease from seven unrelated families and family members who were unaffected by the disease were examined. A homozygous 11 47delA mutation in the arrestin gene was identified in eight patients from six families with Oguchi disease. All patients who were examined exhibited a goldenyellow retinal reflex associated with MizuoNakamura phenomenon and impairment of rod function in dark adaptation tests, although fundus examination showed slight variation in these findings. Four patients with the mutation had slightly reduced visual acuity, and the electroretinograms of three patients showed slightly reduced amplitudes during 30Hz flicker electroretinography. Patients with Oguchi disease associated with the arrestin 1147delA rnutation typically demonstrate retarded rod adaptation, whereas some patients have slightly impaired cone function.