[Clinical, morphological and biochemical studies on muscle carnitine deficiency (author's transl)].

: This report deals with two sisters who died with eight, respectively ten weeks under the signs of respiratory failure caused by progressive muscular weakness. Only an elevated cerebrospinal fluid protein was suspicious of an additional disturbance of the central nervous system. Muscle biopsy revealed a vacuolar myopathy. Histochemistry showed lipid storage, increased mitochondrial enzyme activity, and to a lower degree, glycogen accumulation especially in type I muscle fibers. Electron microscopy confirmed elevated lipid content in combination with increased, enlarged and abnormally structured mitochondria. Biochemical studies on muscle biopsy, in comparison with normal children, showed a significant decrease of carnitine content and an increased activity of carnitine palmityltransferase. Retrospectively from a clinical point of view this disease is suggestive of "systemic carnitine deficiency", even if some symptoms (hepatomegaly, cardiomyopathy) were not present and serum- and liver carnitine was not measured because the children died before the diagnosis of muscle carnitine deficiency was confirmed. The clinical picture of these two fatal cases is compared with another observation of muscle caritine deficiency. This child shows only a mild course of muscle disorder, but very similar morphological changes in muscle biopsy. Biochemically, there was a clear decrease in muscular carnitine, while the serum levels were in the normal range. The activity of muscular carnitine palmityltransferase was also normal.