Medium-chain acyl-coenzyme A dehydrogenase deficiency
What is medium-chain acyl-coenzyme A dehydrogenase deficiency?
Medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency is a rare condition that prevents the body from converting certain fats to energy, particularly during periods without food (fasting). People with this disorder have inadequate levels of an enzyme that breaks down (degrades) a certain group of fats called medium-chain fatty acids. Typically, initial signs and symptoms of this disorder occur during infancy or early childhood and may include vomiting, lack of energy (lethargy), and low blood sugar (hypoglycemia). Serious complications such as seizures, breathing difficulties, liver problems, cardiac arrest, brain damage, coma, and sudden unexpected death are also a risk. Episodes of medium chain acyl-coenzyme A dehydrogenase deficiency can be triggered by periods of fasting or illnesses such as viral infections, particularly when eating is reduced.
This condition is sometimes mistaken for Reye syndrome, a severe disorder that develops in children while they appear to be recovering from viral infections such as chicken pox or flu. Most cases of Reye syndrome are associated with the use of aspirin during these viral infections.
How common is medium-chain acyl-coenzyme A dehydrogenase deficiency?
Worldwide, medium-chain acyl-coenzyme A dehydrogenase deficiency is estimated to affect 1 in 5,000 to 17,000 live births. In the United States, the estimated frequency of this disorder is 1 in 15,000 live births. The condition is more common among individuals of northern European ancestry.
What genes are related to medium-chain acyl-coenzyme A dehydrogenase deficiency?
Mutations in the ACADM gene cause medium-chain acyl-coenzyme A dehydrogenase deficiency.
Mutations in the ACADM gene lead to inadequate levels of an enzyme called medium-chain acyl coenzyme A (CoA) dehydrogenase. Without this enzyme, medium-chain fatty acids from food and from fats stored in the body cannot be broken down and processed. As a result, these fatty acids are not converted into energy, which can lead to characteristic signs and symptoms of this disorder, such as lethargy and low blood sugar. Levels of medium-chain fatty acids or partially degraded fatty acids may build up in tissues and can damage the liver and brain, causing more serious complications.
How do people inherit medium-chain acyl-coenzyme A dehydrogenase deficiency?
This condition is inherited in an autosomal recessive pattern, which means two copies of the gene in each cell are altered. Most often, the parents of an individual with an autosomal recessive disorder are carriers of one copy of the altered gene but do not show signs and symptoms of the disorder.
What other names do people use for medium-chain acyl-coenzyme A dehydrogenase deficiency?
* ACADM deficiency
* MCADD
* MCAD deficiency
* MCADH deficiency
* Medium chain acyl-CoA dehydrogenase deficiency
