• Japanese family
• Norrie disease
• gene analysis
• nonsense mutation
• hyperplastic primary vitreous

Norrie disease (ND) is an X linked genetic disorder causing bilateral blindness in early infancy because of severely dysplastic retinas. The major disease phenotype is a retrolental mass caused by undifferentiated, proliferated vitreous and retina, accompanied by maldeveloped anterior segment, leading to atrophy of the eyeball. A certain number of patients show psychomotor retardation or hearing impairment as part of a multisystem disorder.¹ After the identification of the gene for ND, various types of pathological mutations have been documented in different ethnic groups.^2,3 Phenotype-genotype evaluation has clarified that a mutation in the ND gene may also be responsible for a separate clinical entity, exudative vitreoretinopathy, retinopathy of prematurity, or unclassified retinal dysplasia.^4,5 The clinical distinction between sporadic ND and bilateral persistent hyperplastic primary vitreous (PHPV) can be difficult.^6,7 We report a novel truncating mutation of the ND gene in a Japanese family, in whom the proband was initially diagnosed with a sporadic form of PHPV.