Two cases of hereditary optic atrophy associated with an enzymatic defect of the respiratory chain.

Hereditary optic atrophy is a significant cause of optic atrophy in children. We report two male siblings who suffered profound irreversible loss of vision over a 2-month period. Neither patient had any prior ophthalmic problems. Both siblings had a metabolic disorder characterized by transient episodes of ataxia and paresis, whereas in one brother a slight increase of lactate in blood and cerebrospinal fluid was detected during an acute episode. Respiratory chain defect in complex I was confirmed in one patient.