3-hydroxy-3-methylglutaryl-CoA lyase deficiency 1972009 217460466 2008-06-06T03:12:52Z Arcadian 104523 image {{Infobox_Disease | Name = {{PAGENAME}} | Image = HMG coenzyme A.svg | Caption = [[HMG-CoA]] | DiseasesDB = 29826 | ICD10 = | ICD9 = | ICDO = | OMIM = 246450 | MedlinePlus = | eMedicineSubj = | eMedicineTopic = | MeshID = C008047 }} '''3-hydroxy-3-methylglutaryl-CoA lyase deficiency''' also referred to as '''HMG-CoA lyase deficiency''' or '''Hydroxymethylglutaric aciduria''', is an uncommon inherited disorder in which the body cannot properly process the [[amino acid]] leucine. Additionally, the disorder prevents the body from making [[ketone]]s, which are used for energy during fasting. ==Presentation== This disorder usually appears within the first year of life. The signs and symptoms of [[HMG-CoA lyase]] deficiency include [[vomiting]], [[dehydration]], [[lethargy]], [[convulsion]]s, and [[coma]]. When episodes occur in an infant or child, [[blood sugar]] becomes extremely low ([[hypoglycemia]]), and harmful compounds can build up and cause the blood to become too acidic ([[metabolic acidosis]]). These episodes are often triggered by an infection, fasting, strenuous exercise, or sometimes other types of stress. ==Differential diagnosis== 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. ==Cause== [[Mutation]]s in the ''HMGCL'' [[gene]] cause 3-hydroxy-3-methylglutaryl-CoA lyase deficiency. The [[enzyme]] made by the ''HMGCL'' gene plays an essential role in breaking down dietary proteins and [[lipid|fats]] for energy. Specifically, the enzyme is responsible for processing leucine, an amino acid that is part of many proteins. This enzyme also produces ketones during the breakdown of fats. If a mutation in the ''HMGCL'' gene reduces or eliminates the activity of this enzyme, the body is unable to process leucine or make ketones properly. A lack of ketones leads to hypoglycemia, and compounds called [[organic acids]] (which are formed as products of amino acid and fat breakdown) can cause the blood to become too acidic. Metabolic acidosis and hypoglycemia impair tissue function, especially in the [[central nervous system]]. ==Incidence== This is a rare condition that has been reported in fewer than 100 individuals throughout the world. This condition is inherited in an [[autosomal recessive]] pattern. ==See also== * [[3-hydroxy-3-methylglutaryl-CoA lyase]] ==References== ''This article incorporates public domain text from [http://ghr.nlm.nih.gov The U.S. National Library of Medicine]'' ==External links== * [http://www.oaanews.org Organic Acidemia Association] * {{NLM|3hydroxy3methylglutarylcoalyasedeficiency}} *http://ghr.nlm.nih.gov/condition=3hydroxy3methylglutarylcoenzymealyasedeficiency;jsessionid=3329E3ED085B1A6E5BE651FC9159D676 *http://www.newbornscreening.info/Parents/organicaciddisorders/HMGCoA.html {{Amino acid metabolic pathology}} [[Category:Genetic disorders]] [[Category:Inborn errors of metabolism]]