Medium-Chain Acyl-CoA Dehydrogenase Deficiency

Fatty acid oxidation disorders (FAODs) are inborn errors of metabolism that result in deficient energy production during fasting and catabolic stress. Fatty acid oxidation occurs in the mitochondria and involves multiple enzymes to oxidize fatty acid chains. FAODs are categorized by the length of the fatty acid chain affected by each disorder. Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is a prevalent FAOD that affects fatty acid chains of C6 to C12 length. Medium-chain acyl-CoA dehydrogenase (MCAD) catalyzes the mitochondria's first step of medium-chain fatty acid oxidation. MCADD is an autosomal recessive disorder caused by mutations in the acyl-CoA dehydrogenase medium chain () gene. The inability to provide energy to tissues when glycogen stores are depleted secondary to MCADD results in a wide array of symptoms. Hypoketotic hypoglycemia with vomiting, progressing to seizures, and coma are typical presentations of this disease. MCADD is also thought to be responsible for a small portion of sudden infant death syndrome (SIDS) cases. This disease may become evident in early childhood, typically within the first 24 months of life, or remain asymptomatic until adulthood. While newborn screening (NBS) has helped in the early identification of asymptomatic individuals, current literature lacks a concise and contemporary review of MCADD and its management. Nevertheless, clinicians must be proficient in the identification and management of this disease because early diagnosis can dramatically improve the prognosis for individuals with MCADD. Therefore, to achieve this goal, clinicians should obtain the most up-to-date knowledge regarding the disease's pathogenesis, diagnostic tools, and treatment options.