Congenital lactic acidosis due to a defect of pyruvate dehydrogenase complex (E1). Clinical, biochemical, nerve biopsy study and effect of therapy.

We report an 8-year-old patient with clinical features suggesting Leigh's syndrome and with a decreased activity of the E1 component of the pyruvate dehydrogenase complex in cultured skin fibroblasts. A nerve biopsy showed the presence of severe peripheral neuropathy, rarely described in the literature. The partial correction of lactic acidosis with oral sodium bicarbonate chronic therapy may result in a slow evolution of the clinical symptoms.