The presentation of patient with SPCD can be incredibly varied, from asymptomatic to lethal cardiac manifestations. Early cases were reported with liver dysfunction, muscular findings (weakness and underdevelopment), hypoketotic hypoglycemia, cardiomegaly, cardiomyopathy and marked carnitine<unk>  in plasma and tissues, combined with increased excretion in urine. Patients who present clinically with SPCD fall into two categories, a metabolic presentation with hypoglycemia and a cardiac presentation characterized by cardiomyopathy. Muscle weakness can be found with either presentation. In countries with expanded newborn screening, SPCD can be identified shortly after birth. Affected infants show low levels of free carnitine and all other acylcarnitine species by tandem mass spectrometry. Not all infants with low free carnitine are affected with SPCD. Some may have carnitine<unk>  secondary to another metabolic condition or due to maternal carnitine<unk> . Proper follow-up of newborn screening results for low free carnitine includes studies of the mother to determine whether her carnitine<unk>  is due to SPCD or secondary to a metabolic disease or diet. Maternal cases of SPCD have been identified at a higher than expected rate, often in women who are asymptomatic. Some mothers have also been identified through newborn screening with cardiomyopathy that had not been previously diagnosed. The identification and treatment of these asymptomatic individuals is still developing, as it is not clear whether they require the same levels of intervention as patients identified with SPCD early in life based on clinical presentation.
Systemic primary carnitine deficiency
Short-chain acyl-coenzyme A dehydrogenase deficiency
Medium-chain acyl-coenzyme A dehydrogenase deficiency
Very long-chain acyl-coenzyme A dehydrogenase deficiency
Long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency
Carnitine-acylcarnitine translocase deficiency
Multiple carboxylase deficiency
Carnitine palmitoyltransferase II deficiency