Carnitine levels in normal children and adults and in patients with diseases muscle.

An assay for evaluating carnitine levels in normal children and adults is described. After a 12-hour period of fasting, individual variations in 24-hour urinary excretion of carnitine were observed in adults. In children, there was a significant decrease in excretion from the 10th month to the third year, and then an increase until the 10th year. There was no significant difference between children and adults in the serum and skeletal muscle levels. Muscle carnitine levels were also studied in 12 cases of lipid-storage myopathy and in cases of other muscle diseases, including Duchenne muscular dystrophy in children.