pediatrics
Beta Oxidation Cycle Disorders
Medium chain acyl CoA dehydrogenase deficiency (MCADD)
This deficiency is the most common defect in the beta-oxidation cycle. Clinical manifestations typically begin after 2 to 3 months of age and usually follow fasting (as little as 12 hours). Patients have vomiting and lethargy that may progress rapidly to seizures, coma, and sometimes death (which can also appear as sudden infant death syndrome). During attacks, patients have hypoglycemia, hyperammonemia, and unexpectedly low urinary and serum ketones. Metabolic acidosis is often present but may be a late manifestation. in urine or by detecting enzyme deficiency in cultured fibroblasts; however, DNA testing can confirm most cases. MCADD is now included in routine Screening Tests for Newborns in all states in the US. IV at 1.5 times the fluid maintenance rate ( see Maintenance requirements ); some clinicians also advocate carnitine supplementation during acute episodes. Prevention is a low-fat, high-carbohydrate diet and avoidance of prolonged fasting. Cornstarch therapy is often used to provide a margin of safety during overnight fasting. 