Abstract
A patient with muscular weakness demonstrating pathological lipid accumulation and abnormal mitochondria in skeletal muscle has been studied. The lipid accumulation and mitochondrial changes are thought to be related to the established deficiency of carnitine in this patient's muscle. The symptoms of muscular weakness associated with lipid accumulation in the skeletal muscle in the absence of complaint of muscle cramps or myglobinuria are thought to be diagnostic of carnitine deficiency. The failure of the sarcoplasmic reticulum to accumulate Ca2+ is discussed. The patient's strength responded dramatically when propranolol was added to his steroid therapy.