Multiple acyl CoA dehydrogenase deficiency due to impairment of a riboflavin-dependent reaction common to straight and branched-chain acyl CoA molecules commonly is associated with carnitine depletion and a lipid myopathy in which skeletal muscle weakness and fatigability are prominent features. Of great importance is the fact that some of these patients respond to pharmacologic doses of riboflavin (up to 100 mg three times per day) with dramatic reversal of clinical symptoms. Additional therapeutic measures include L-carnitine replacement to counter secondary carnitine deficiency. These patients are subject to life-threatening, Reye's syndrome - like metabolic crises triggered by metabolic stresses that lead to fatty acid mobilization. Strict maintenance of carbohydrate intake with a low-fat, high-carbohydrate diet is crucial.

Deficiency of long- and short-chain hydroxyacyl CoA dehydrogenases have been recognized and other beta-oxidation defects likely will be identified. It seems likely that the principles of treatment for these disorders will be similar to those for other lipid defects: avoid lipid mobilization, ensure carbohydrate availability, and supplement with carnitine.

VLCAD (very long chain acyl CoA dehydrogenase) LCAD (long chain acyl CoA dehydrogenase) MCAD (medium chain acyl CoA dehydrogenase) SCAD (short chain acyl CoA dehydrogenase)