Original reports of long chain Acyl-CoA dehydrogenase deficiency (LCAD) in the literature were in error and all previously published cases of LCAD deficiency have been shown to be VLCAD deficiency. VLCADD deficiency is inherited in an autosomal recessive fashion. Cardiomyopathy may lead to weakening in the force of heart contractions, decreased efficiency in the circulation of blood through the lungs and to the rest of the body (heart failure), and various associated symptoms will depend upon the nature and severity of the condition, patient age, and other factors. For example, there may be abnormal thickening (hypertrophy) or stretching and enlargement (dilation) of the the heart (i.e., hypertrophic or dilated cardiomyopathy). Individuals with VLCADD deficiency may have fat deposits (fatty infiltration) and abnormal enlargement of the liver (hepatomegaly) poor muscle tone (hypotonia) and/or evidence of cardiomyopathy. (For further information, please see Standard Therapies below.) Without prompt, appropriate treatment, such acute episodes may lead to potentially life-threatening complications. However, because hypoglycemia usually occurs well after other symptoms, home glucose monitoring is not typically useful.Īffected individuals of any age are at risk to experience recurrent increased acid levels in blood and body tissues (metabolic acidosis) sudden cessation of breathing (respiratory arrest) and even cardiac arrest. A patient’s blood or urine will be examined for these patterns if VLCADD is suspected. (Ketone bodies are chemical substances normally produced by fatty acid metabolism in the liver.) There are very complicated patterns of blood chemicals and concentrations of unusual acids in the blood. The hypoglycemia associated with VLCADD occurs with little or no accumulation of ketone bodies (hypoketotic hypoglycemia) in the blood. Cardiomyopathy and cardiac arrhythmias can occur at any age.
Some patients may show their first symptoms in early adolescence. After this age, muscle symptoms predominate including periodic attacks of pain, fatigue, and/or muscle breakdown (rhabdomyolysis) with activity or otherwise mild illnesses. The incidence of hypoglycemia decreases with age and is uncommon after about age 6. Cardiomyopathy is uncommon in infancy but may be life threatening when present. Similar symptoms may occur any time in the first few months of life. Infants also are at risk for weakness of the heart muscles (cardiomyopathy), abnormal heart rhythms and cardiorespiratory failure. These infants show signs of low blood sugar (hypoglycemia), irritability and listlessness (lethargy). Since the advent of expanded newborn screening programs using tandem mass spectrometry technology, most VLCADD infants in the United States are being detected neonatal period.Ĭhildren with early-onset VLCADD present with symptoms within days or weeks after birth. In reality, patients can present with a combination of symptoms and the disease is best thought of as being a continuum. The mitochondria are small, well-defined structures that are found in the cytoplasm of cells and in which energy is generated from the breakdown of complex substances into simpler ones (mitochondrial oxidation).Ĭlassically, two forms of VLCADD have been described: an early-onset, severe form which, if unrecognized and undiagnosed, can lead to extreme weakness of the heart muscles (cardiomyopathy) and be life-threatening, and a later-onset, milder form that is characterized by repeated bouts of low blood sugar (hypoglycemia). The breakdown of fatty acids takes place in the mitochondria found in each cell. In the past, the name long-chain acyl-CoA dehydrogenase deficiency (LCADD) was applied to one such disease, but today it is clear that all cases once thought to be LCADD are actually VLCADD. VLCADD is one of the metabolic diseases known as fatty acid oxidation (FOD) diseases. It occurs when an enzyme needed to break down certain very long-chain fatty acids is missing or not working properly. Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) is a rare genetic disorder of fatty acid metabolism that is transmitted in an autosomal recessive pattern. 5 Myths About Orphan Drugs and the Orphan Drug Act.Information on Clinical Trials and Research Studies.