A Defect in Mitochondrial Electron-Transport Activity (NADH–Coenzyme Q Oxidoreductase) in Leber's Hereditary Optic Neuropathy

LEBER'S hereditary optic neuropathy is a disorder of unclear cause. Even among members of the same family, the disorder displays a striking degree of clinical heterogeneity, involving an optic neuropathy, at times a movement disorder, and rarely a generalized encephalopathy resulting in death in childhood. Nonneurologic findings include electrocardiographic abnormalities and retinal microangiopathy. 1 2 3 The disease is clearly familial but has been difficult to analyze in terms of classic mendelian genetics. It is transmitted exclusively by women to offspring of both sexes; there have been no demonstrated cases of paternal transmission. Wallace has raised the possibility that the disorder results from . . .