[Heterogeneity of carnitine palmitoyltransferase deficiencies. Deficiency of CPT I in the hepatic form and CPT II in the muscular form]

Abstract

Carnitine Palmitoyl Transferase (CPT) deficiencies are found in 2 different clinical forms: muscular and hepatic. The study of fibroblasts of 2 patients corresponding to each of these situations showed that these phenotypes are associated with different abnormalities of CPT, CPT I in the hepatic type and CPT II in the muscular type. The functional consequences of both abnormalities are different. In the hepatic type, CPT I deficiency induces a lack of long chain fatty acid (LCFA) oxidation in fibroblasts as well as, probably, in the patient's liver. In the muscular type, CPT II deficiency has no functional consequences in the fibroblast, contrary to what is observed in the patient's muscle. It is postulated that control of the mitochondrial LCFA oxidation in the liver and in the fibroblasts depends on CPT I, while it depends on CPT II in the muscle.