46 Medium-chain acyl-coenzyme a dehydrogenase deficiency (mcadd) is an inherited metabolic disorder that prevents the body from converting certain fats to energy, particularly during periods without food (fasting). normally, through a process called fatty acid oxidation, several enzymes work in a step-wise fashion to break down (metabolize) fats and convert them to energy. people with mcadd do not have enough of an enzyme needed for the step that metabolizes a group of fats called medium-chain fatty acids. mcadd is caused by mutations in the acadm gene and is inherited in an autosomal recessive manner. treatment includes avoidance of fasting and of medium chain triglycerides in the diet