Carnitine plays essential role in energy metabolism .Systemic primary carnitine deficiency is a genetic disorder caused by decreased or absent organic cation transporter type 2 (OCTN2) carnitine transporter activity, resulting in low serum carnitine levels and decreased carnitine accumulation inside cells. The decrease carnitine results in impaired fatty acid oxidation. Primary carnitine deficiency presents a hypoketotic, hypoglycemia and hepatic encephalopathy. Recently, primary carnitine deficiency has been associated with neurodevelopmental disorders including autism spectrum disorders. A seven year-old schoolgirl with intellectual deficit, autistic features and primary carnitine deficiency has been reported. A significant decrease in carnitine levels has been shown in patients with autism and this has been related to the existence of a mitochondrial disease and more severe autism. The early identification of patients with low levels of carnitine or primary carnitine deficiency, with the different methods of measuring free carnitine, including tandem mass spectrometry could help to identify these patients early and achieve an early treatment and better neurological prognosis, because autism spectrum disorders may be preventable in this subgroup. We hope that this paper is useful to neurologists and pediatricians, and may give them more reason to suspect a diagnosis of PCD and autism.
Mutations in the organic cation/carnitine transporter OCTN2 in primary carnitine deficiency
