[Abnormal regulation of carnitine palmitoyltransferase in monozygotic twins as the cause of rhabdomyolysis].

Severe myalgias, accompanied by reddish brown discolouration of the urine, occurred after strenuous exercise (all-day hockey competition) in a 21-year-old competitive athlete. Creatine kinase concentration was 1914 U/l, but there were no abnormal physical findings. The myalgias disappeared within three days. A biopsy from the lateral vastus muscle in the patient and his monozygotic twin brother showed normal total activity of carnitine palmitoyltransferase (CPT), but residual activity after inhibition with malonyl-CoA and Triton X-100 was clearly reduced in both brothers. Thus the illness was a rhabdomyolysis due to a, presumably inherited, abnormal regulation of CPT. The symptoms can be precipitated by fasting, marked physical exertion, cold or viral infection.