Long Chain 3-Hydroxyacyl-CoA Dehydrogenase Deficiency

Long Chain 3-Hydroxyacyl-CoA Dehydrogenase (LCHAD) deficiency is an inherited disorder that prevents the body from using certain fats as an energy resource. Problems related to LCHAD deficiency can be triggered by periods of fasting or by illnesses such as viral infections. Signs and symptoms of LCHAD deficiency usually begin appearing in early infancy. These include feeding difficulties, lack of energy, low blood sugar, weak muscle tone, liver problems, and abnormalities in the retina. As children with LCHAD deficiency grow, they may experience muscle pain, breakdown of muscle tissue, and a loss of sensation in their arms and legs. Additional symptoms may include serious heart problems, breathing difficulties, coma, and sudden death. Many complications of LCHAD deficiency can be alleviated by avoiding fasting and prolonged excercising. A low fat, high carbohydrate diet, as well as Medium Chain Triglyceride oil (MCT oil) and L-carnitine supplements are generally recommended for individuals with this disorder. LCHAD deficiency is caused by pathogenic variants in the HADHA gene.

LCHAD deficiency is inherited in an autosomal recessive manner. This type of inheritance requires the presence of two copies of a pathogenic variant in the gene for a person to have the genetic disease. Both parents must be carriers of a pathogenic variant in the gene in order to be at risk to have an affected child. The child must inherit a pathogenic variant from each carrier parent in order to be affected. There is a 1 in 4 chance that a baby will inherit two mutated copies of the gene and be affected when both parents are carriers.

There are generally no signs or symptoms associated with being a carrier for LCHAD deficiency. However, the risk to have a child affected with this disorder is increased. Testing of reproductive partners is recommended for carriers of LCHAD deficiency.

The occurence of LCHAD deficiency has been published for only a few countries. In Sweden, about 1 in 50,000 newborns is affected, in Germany it is estimated to be 1 in 170,000 newborns, and in the Finnish population it is 1 in 62,000 newborns. The combined data of the newborn screening programs of Australia, Germany, and USA shows that 1 in 250,000 newborns is affected.

Genetic Home Reference: Long Chain 3-Hydroxyacyl-CoA Dehydrogenase deficiency (http://ghr.nlm.nih.gov/)
Newbornscreening Info: LCHADD (http://www.newbornscreening.info/Parents/fattyaciddisorders)

OMIM [Long-chain 3-hydroxyacyl-coa dehydrogenase deficiency: 609016] (http://www.ncbi.nlm.nih.gov/omim)

• Full gene sequencing