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

A fatal case of carnitine deficiency is described. The patient had intermittent metabolic 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 mitochondria in myofibres. The muscle carnitine level was less than one-seventh of the lowest value encountered 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.