Carnitine deficiency: clinical, morphological, and biochemical observations in a fatal case

SUMMARY A fatal case of carnitine deficiency is described. The patient had intermittent met-abolic acidosis, fluctuating hepatomegaly, and progressive muscle weakness since 22 months of age. One of two liver biopsies revealed lipid accumulation in the hepatocytes, and a muscle biopsy at age 5 years showed a lipid storage myopathy. Type 1 fibres were the most severely affected. Satellite and vascular endothelial cells also contained abnormal lipid deposits. Quantitative electron microscopy demonstrated an approximately 50-fold increase in lipid material, and a twofold increase in mito-chondria in myofibres. The muscle carnitine level was less than one-seventh of the lowest value en-countered in 74 biopsies from non-weak or neuromuscular disease controls. The basic abnormality in this patient is assumed to be a defect in carnitine biosynthesis. The biochemical basis of most muscle diseases is not known. Until recently, only the muscle glycogenoses conditioned by distinct enzyme deficiencies, and the myopathy associated with xanthine oxidase defi-ciency (Chalmers et al., 1969) could be considered as biochemically distinct. Since 1973 two metaboli