ENGEL and Angelini have reported that skeletal-muscle carnitine deficiency is associated with a lipid-storage myopathy.¹ Since then, two major clinical syndromes have been described²: a systemic form, in which carnitine concentrations are low in serum and liver, and a muscular form, in which carnitine concentrations are normal in serum but low in muscle. However, a few patients have the characteristics of both variants, and the two main patient groups have clinically heterogeneous disease, suggesting different biochemical defects. The basic defects causing carnitine deficiency in these syndromes are not known. Hypocarnitinemia also occurs in some inborn errors of metabolism — . . .