Primary and secondary carnitine deficiency in man

Patients with muscular CD had low muscle carnitine, normal liver and plasma carnitine and excreted normal amounts of free carnitine and carnitine esters in their urine. Patients with systemic CD had low carnitine in plasma, muscle and liver, excreted low amount of free carnitine and normal amounts of carnitine esters in their urine. All the patients with 'primary' CD had abnormally high levels of long-chain acyl-carnitines in plasma, suggesting some defect of long-chain fatty acyl-carnitine metabolism. However, the oxidation of long-chain fatty acids and the activity of related enzymes were normal (see results) in isolated muscle mitochondria from these patients. Moreover, no abnormal fatty metabolite was seen in their urine: the pathogenesis of their CD is therefore still obscure.