Medium-chain acyl-CoA dehydrogenase deficiency (MCAD deficiency or MCADD), is a disorder of fatty acid oxidation that impairs the body's ability to break down medium-chain fatty acids into acetyl-CoA. The disorder is characterized by hypoglycemia and sudden death without timely intervention, most often brought on by periods of fasting or vomiting.
Prior to expanded newborn screening, MCADD was an underdiagnosed cause of sudden death in infants. [Source: Wikipedia 
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