As a subset of CEDNIK patients also show ophthalmological abnormalities such as optic nerve hypoplasia and atrophy, we used electroretinogram (ERG) to assess retinal function in 21 mice, including five wild type, eight Snap29+/− and eight Snap29−/− mutant mice. The gene discussed is SNAP29; the disease is Autosomal dominant optic atrophy, classic type.