Diagnosis of mitochondrial fatty acid oxidation defects.

Inherited defects of mitochondrial beta-oxidation of fatty acids lead to hypoketotic hypoglycemia during prolonged fasting. Affected patients may present with episodes of a Reye-like illness or even sudden child death. The number of currently detected patients with medium-chain acyl-CoA dehydrogenase deficiency--the most common disease in this area--is indicative of a high frequency, possibly comparable to that of phenylketonuria.