Familial intermittent ataxia due to a defect of the E1 component of pyruvate dehydrogenase complex

Disturbances of pyruvate metabolism have been implicated in the aetiology of several neurological disorders including Leigh's disease and familial ataxia. We have re-investigated a patient whose initial description documented intermittent ataxia, a presumed disorder of pyruvate metabolism and an X-linked pattern of inheritance. Recent studies showed he had slow oxidation of pyruvate, low pyruvate dehydrogenase complex (PDC) activity and immunochemical evidence of E1 deficiency in skeletal muscle mitochondria. This is consistent with the recent finding that the gene for E1 alpha is on the X chromosome.