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]]