Variable clinical presentation in patients with defective E1 component of pyruvate dehydrogenase complex

Clinical findings are presented for 30 patients with lactic acidemia in whom activity of the pyruvate dehydrogenase complex in fibroblasts was significantly (P = less than 0.01) below that of control cell lines. Residual activity of the activated complex ranged from 1.6% to 68.5% of control activity. Seven patients died before 6 months of age, and another five before reaching 2 years of age. Sixteen of the surviving patients and the five who died between 6 months and 2 years all had psychomotor retardation. Seventeen children had structural central nervous system damage, as determined either by computed tomography or at autopsy. The extent and location of damage varied from cerebral atrophy to the development of cystic lesions in the cerebral cortex, basal ganglia, and brain stem. Two patients had ataxic episodes only and were not developmentally delayed. This cohort of patients strongly resembles a comparable group assembled from various other reports.