Chronic Leigh Disease: a genetic and biochemical study.

The large family of a 21-year-old man who died of Leigh disease was investigated for evidence of neurological abnormalities and presence of the adenosine triphosphate-thiamine diphosphate phosphoryltransferase inhibitor factor. Of 217 persons (seven generations) included in the pedigree, 68 were examined neurologically and biochemically. Fourteen (20%), 5 of whom had abnormal neurological findings, were found to excrete the inhibitor factor. Clinical manifestations varied from severe neurological affliction to subtle deficits. A chronic relapsing course was frequently encountered, with exacerbations occurring in association with apparent metabolic stress. Parental consanguinity was identified in the propositus as well as in other family members with neurological abnormalities. Males and females were affected, and no vertical transmission of the trait was found. These multigenerational data suggest that Leigh disease in adults is inherited in an autosomal recessive manner and has variable degrees of expression with a wide spectrum of neurological manifestations.