Clinical and genetical manifestations in 34 families with Leber's hereditary optic neuropathy (LHON).

The clinical and genetical manifestations of 64 patients of 34 families with LHON, taken up in an ophthalmogenetic register for LHON, are discussed. The disorder appeared to occur sporadically in 41.2% of the patients. Genotypic characteristics of the pedigrees revealed the 11778 mutation in 57.5% of the families, the 3460 mutation in 21.2% and the 15257 mutation in 9.1%. One family carried only a secondary mutation pattern. Fourteen percent of patients with the 11778 mutation showed recovery of their visual acuity. Visual recovery with the 3460 and 15257 mutation was respectively 21% and 33%. Our youngest patient was 4 years old.