Includes

Carnitine, Total; Carnitine, Free; Carnitine, Esters; Esterified/Free Ratio

Why It Is Done

Serum carnitine analysis is useful in the diagnosis and monitoring of patients with carnitine deficiency (either primary or secondary). Primary carnitine deficiency is an autosomal recessively inherited genetic condition that affects carnitine uptake by cells and tissues through a defect in the plasma membrane carnitine transporter. Secondary carnitine deficiency can be seen in some disease states or in patients on carnitine-poor diets, but is also seen in a number of metabolic disorders. In these disorders, carnitine complexes with the accumulated substrate of the blocked metabolic step, and the resulting acylcarnitine ester is excreted in the urine, leading to a depletion of carnitine in the patient.