Several groups of inherited metabolic disorders can cause carnitine deficiency, including, organic acidemias and fatty acid oxidation defects such as very long chain acyl-CoA dehydrogenase (VLCAD), medium-chain acyl-CoA dehydrogense (MCAD), long-chain hydroxyacyl-CoA dehydrogenase (LCHAD), and carnitine palmitoyltransferase II (CPT II) deficiencies. Here, CPT2 is linked to systemic primary carnitine deficiency disease.