Fasting hypoglycemia resulting from hepatic carnitine palmitoyl transferase deficiency.

Two sisters developed severe hypoglycemia at 8 months of age, resulting in death in one of them. Metabolic studies of the second revealed decline of blood glucose concentration and low plasma ketone body values during a 20-hour fast, both reversed by administration of medium-chain triglycerides. Carnitine palmitoyl transferase activity was absent in the liver extract of the patient; lack of this enzyme impairs long-chain fatty acid oxidation and ketogenesis. Failure of gluconeogenesis could result from decreased production of acetyl-CoA and NADH.