What is MCADD

Medical Explanation

MCADD, short for Medium-chain acyl-CoA dehydrogenase deficiency, is a rare inherited genetic condition which inhibits the conversion of certain fats into energy, in particular, during times of fasting.It is estimated that approximately 1 in 17,000 US citizens are born with MCADD and is especially common among individuals of northern European ancestry. MCADD is inherited via an autosomal recessive pattern, which means both parents of the child born with MCADD must be carriers of the mutated gene, but may not show symptoms of the condition.

Specifically, MCADD is a result of a mutation in the ACADM gene which is the gene that instructs the enzyme called medium-chain acyl-CoA dehydrogenase to break down or metabolize a group of fats called medium-chain fatty acids.These fatty acids are found in consumed foods and fat tissues found in the body. It is these fatty acids that are the major source of energy the heart and muscles and also for the liver and other tissues during fasting periods.

As a result of the mutation, an insufficient amount of energy is metabolized and therefore the body and organs do not receive enough energy to function at a normal rate. There is no argument that the risks of living with MCADD and not monitoring MCADD closely are quite dangerous. Due to the lack of energy being converted people with MCADD are at risk to experience seizures, breathing problems, liver problems, brain damage, coma, and most upsetting, sudden death. It is also reported that 1 / 100 infant deaths thought to be Sudden Infant Death Syndrome (SIDS) may be caused by MCADD as it is also reported that 1 / 5 children with MCADD will die with the onset of their first illness prior to diagnosis.

Signs and Symptoms

Signs and symptoms of MCADD are similar to ordinary new born behavior. These symptoms are more likely to appear during infancy or early childhood, however it is possible for symptoms to occur later in life as well. These symptoms include vomiting, diarrhea, difficulty breathing, seizures, lethargy or lack of energy, and low blood sugar (also known as hypoglycemia).

Monitoring and Living with MCADD

MCADD monitoring is predominantly reliant on current health condition and close monitoring of diet. ANY illnesses such as viral infections should be taken very seriously and treated immediately. Children born with MCADD should avoid long periods of fasting, no longer than ten or twelve hours when well. The diet should consist of low fat, high carbohydrates and high sugar drinks when they are ill. Infants must have at least one night feeding or late night snack as ten hours may be too long.
It must be stressed that a routine and consistent diet must be maintained to prevent any attacks occurring from MCADD. Again, any health concerns such as viruses must be taken very seriously and treated immediately by your local emergency room.


All information provided on this site is obtained from the following resources:


For more detailed information and links to other resources please refer to the above links.

Additionally, our organization has developed a convenient 2-sided brochure which outlines the above information. In an effort to educate and bring awareness to MCADD, we have posted the brochure here for you to download and share as you wish:

Important Information for Parents or Expectant Parents Brochure