MCAD is one of the enzymes responsible for dehydrogenation of fatty acids as they cycle through the beta-oxidation spiral. MCADD presents in early childhood with hypoketotic hypoglycemia and liver dysfunction, often preceded by extended periods of fasting or an infection with vomiting. Infants who are exclusively breast-fed may present in this manner shortly after birth, due to poor feeding. In some individuals the first manifestation of MCADD may be sudden death following a minor illness. A number of individuals with MCADD may remain completely asymptomatic, provided they never encounter a situation that sufficiently stresses their metabolism. With the advent of expanded newborn screening, some mothers have been identified with MCADD after their infants had positive newborn screens for low carnitine levels. The enzyme MCAD is responsible for the dehydrogenation step of fatty acids with chain lengths between 6 and 12 carbons as they undergo beta-oxidation in the mitochondria. Fatty acid beta-oxidation provides energy after the body has used up its stores of glucose and glycogen. This oxidation typically occurs during periods of extended fasting or illness when caloric intake is reduced, and energy needs are increased.
Medium-chain acyl-coenzyme A dehydrogenase deficiency
Short-chain acyl-coenzyme A dehydrogenase deficiency
Long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency
Very long-chain acyl-coenzyme A dehydrogenase deficiency
Holocarboxylase synthetase deficiency
2,4 Dienoyl-CoA reductase deficiency
Systemic primary carnitine deficiency
Malonyl-CoA decarboxylase deficiency