Muscle carnitine palmityltransferase deficiency and myoglobinuria

Muscle carnitine palmityltransferase activity, measured by three different methods, was very low (0 to 20 percent of controls) in a patient with a familial syndrome of recurrent myoglobinuria. Long-chain fatty acyl CoA synthetase activity was normal; acetylcarnitine transferase activity was decreased by 40 percent, and carnitine content was 1.7 times higher than the mean control value. Utilization of palmitate by isolated mitochondria was more impaired than utilization of palmitylcarnitine, suggesting a more severe defect of carnitine palmityltransferase I than transferase II. Thus, myoglobinuria may be due to a genetic defect of lipid metabolism in skeletal muscle.