Carnitine deficiency in inborn errors of metabolism

Several conditions, considered as inborn errors of metabolism, involve severe deficiencies in carnitine in both plasma and muscle. In the absence of evidence suggesting primary carnitine deficiency due to a biosynthetic enzymatic defect in the liver, the various diseases with carnitine deficiency are related to genetic defects in organic acid metabolism leading to blocked mitochondrial beta oxidation. We describe a 4.5-year-old boy and 2 female infants with glutaric aciduria type I, isovaleric acidemia, and long-chain acid dehydrogenase deficiency, in whom severe carnitine deficiency was apparent. In all 3, long-term carnitine treatment proved to be vital and eliminated most of the symptoms.