Defects of β-oxidation including carnitine deficiency

Abstract

Publisher Summary The inherited disorders of mitochondrial β-oxidation are a complex group of disorders. The criteria for the diagnosis of primary carnitine deficiency is proposed as (1) severe reduction of plasma or tissue-carnitine levels, (2) evidence that low carnitine levels impair fatty-acid oxidation, (3) correction of the disorder when carnitine levels are restored towards normal, and (4) absence of other primary defects in fatty-acid oxidation. Those associated with hypoglycemia can be distinguished from other causes of hypoglycemia by simple tests such as the measurement of the major metabolic fuels. However, the availability of sophisticated analytical methods such as tandem-mass spectrometry and gas chromatography–mass spectrometry has allowed the detection of disease-specific metabolites and patterns of metabolites in body fluids and tissue preparations. For some of the disorders direct enzyme measurement is necessary for precise diagnosis, supplemented by investigations at the gene level. Some of the mitochondrial β-oxidation disorders, however, are intractable to treatment such as the severe neonatal forms of glutaric aciduria type II.