Child Neurology: Medium-chain acyl-coenzyme A dehydrogenase deficiency

Medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency (MCADD) is an autosomal recessive inherited fatty acid oxidation disorder. In MCADD, mitochondria cannot process medium-chain fatty acids via the -oxidation pathway because of a lack of MCAD. While patients may be asymptomatic during the prenatal or immediate postnatal periods, patients will experience decompensation due to profound hypoglycemia during fasting or illness with often rapid progression to encephalopathy, seizures, coma, or death. Newborn screening tests can identify virtually all new cases of MCADD in a cost-effective manner, often with reflex follow-up targeted mutation analysis for the 2 most common alleles. With appropriate monitoring, prevention through avoidance of fasting, and intervention during an impending crisis, patients with MCADD can survive into adulthood with no neurologic sequelae.