Acyl-CoA dehydrogenase, very short chain, deficiency of
Acyl-CoA dehydrogenase, very short chain, deficiency of Definition
Short Chain Acyl-CoA Dehydrogenase Deficiency (SCADD) is a condition in which the body fails to oxidize fatty acids because an enzyme is either missing or not functioning correctly. Short-chain acyl-coenzyme A (CoA) dehydrogenase deficiency (SCAD) is a rare condition that stops the body from converting certain fats into energy, especially during periods without food (fasting). People affected with this disorder are not able to break down a certain group of fats called short-chain fatty acids efficiently. Some affected infants will display vomiting, low blood sugar (hypoglycemia), a lack of energy (lethargy), poor feeding, and failure to gain weight and grow at the expected rate (failure to thrive). Other features of this disorder may include poor muscle tone (hypotonia), developmental delays, seizures, and a small head size (microcephaly). The symptoms of short-chain acyl-CoA dehydrogenase deficiency may be activated by periods of fasting or during illnesses such as viral infections. In some cases, signs and symptoms may not exhibit themselves until adulthood, when some individuals may develop muscle weakness and wasting. Other people with gene mutations that can lead to this disorder may have such mild symptoms that they are never diagnosed.
Acyl-CoA dehydrogenase, very short chain, deficiency of Prevalence
This disorder is thought to affect an estimated 1 in 40,000 to 100,000 newborns. The gene defect for SCADD is a genetic trait that is autosomal recessive and is unknowingly passed down from generation to generation. This faulty gene only arises when two carriers have children together and pass it to their offspring. For each pregnancy of two such carriers, there is a 25% probability that the child will be born with the disease and a 50% chance the child will be a carrier for the gene defect.
Acyl-CoA dehydrogenase, very short chain, deficiency of Symptoms and Signs
Symptoms of SCADD are the inability to thrive and hypoglycemia. Over time without proper treatment, development may be delayed.
Acyl-CoA dehydrogenase, very short chain, deficiency of Treatment
Treatment of SCADD typically consists of avoidance of fasting (by frequent meals) and use of glucose IV required when food cannot be tolerated (such as with a virus, cold, flu, etc.). Intake of short-chain fatty acids is best avoided. Supplemental carnitine is recommended for some children affected with SCADD. Fundamental to the medical management of SCAD deficiency is to avoid fasting, especially during periods of high metabolic stress, such as illness. Overnight fasts should be managed with nighttime or late evening feedings where necessary. The addition of food-grade uncooked cornstarch mixed in liquid for a bedtime feeding has aided in decreasing the frequency of morning hypoglycemic episodes in several patients. High carbohydrate intake should be encouraged during illness, with initiation of intravenous glucose supplementation if the child has failed to keep down fluids, or unable to take adequate oral feedings.