Primary Carnitine Deficiency Due to a Failure of Carnitine Transport in Kidney, Muscle, and Fibroblasts

CARNITINE (β-hydroxy-γ-trimethylaminobutyric acid) is an essential cofactor for the oxidation of fatty acids by mitochondria. It serves to carry long-chain fatty acids in the form of their acyl-carnitine esters across the barrier of the inner mitochondrial membrane before β-oxidation. Since 1973,¹ a total of 46 patients have been described with evidence of impaired fatty acid oxidation associated with reduced levels of carnitine.² These patients have been divided into a group with a “systemic carnitine deficiency,” which presents in infancy or early childhood with recurrent episodes of coma and hypoglycemia, and a group with a “muscle carnitine deficiency,” which presents later.