Fatty acid oxidation disorders

[Jessica]

Fatty acid oxidation disorders are lipid metabolism disorders that are caused by a lack or deficiency of the enzymes needed to break down fats, resulting in delayed mental and physical development. Fatty acid oxidation disorders occur when parents pass the defective genes that cause these disorders on to their children.
There are different types of inherited disorders. In fatty acid oxidation disorders, both parents of the affected child carry a copy of the abnormal gene. Because usually two copies of the abnormal gene are necessary for the disorder to occur, usually neither parent has the disorder. (See also Overview of Hereditary Metabolic Disorders.)
Fats (lipids) are an important source of energy for the body. The body’s store of fat is constantly broken down and reassembled to balance the body’s energy needs with the food available. Several enzymes help break down fats so that they may be turned into energy.
Children who have one of these disorders are missing or have a deficiency of the enzymes needed to break down (metabolize) fats. The lack of these enzymes leaves the body short of energy and allows breakdown products, such as acyl-CoA, to accumulate. The enzyme most commonly deficient is medium-chain acyl-CoA dehydrogenase (MCAD). Other enzyme deficiencies include short-chain acyl-CoA dehydrogenase (SCAD) deficiency, long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency, very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency, glutaric acidemia type II, and mitochondrial trifunctional protein (TFP) deficiency. Most of these disorders begin in infancy.
Treatment of fatty acid oxidation disorders varies depending on the type of fatty substances that accumulate in the blood and tissues.