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| {{Infobox_Disease
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| | Name = {{PAGENAME}}
| | '''For patient information click [[{{PAGENAME}} (patient information)|here]]''' |
| | Image = Galactose Haworth.png
| | {{Galactosemia}} |
| | Caption = [[Galactose]]
| | {{CMG}}; {{AE}} {{DD}} |
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| | DiseasesDB_mult =
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| | ICD10 = {{ICD10|E|74|2|e|70}}
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| | ICD9 = {{ICD9|271.1}}
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| | OMIM =
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| | MeshID = D005693
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| {{SI}} | |
| {{CMG}} | |
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| ==Overview==
| | {{SK}} Classic galactosemia, galactokinase deficiency |
| '''Galactosemia''' is a rare genetic metabolic disorder which affects an individual's ability to properly metabolize the sugar [[galactose]]. In individuals with galactosemia, the enzymes needed for further metabolism of galactose are severely diminished or missing entirely, leading to toxic levels of galactose to build up in the blood, resulting in [[hepatomegaly]] (an enlarged [[liver]]), [[renal failure]], [[cataract]]s, and [[brain damage]].
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| Goppert first described the disease in 1917,<ref>Goppert F. ''Galaktosurie nach Milchzuckergabe bei angeborenem, familiaerem chronischem Leberleiden.'' Klin Wschr 1917;54:473-477.</ref> with its cause as a defect in galactose metabolism being identified by a group led by [[Herman Kalckar]] in 1956.<ref>{{cite journal |author=Isselbacher KJ, Anderson EP, Kurahashi K, Kalckar HM |title=Congenital galactosemia, a single enzymatic block in galactose metabolism |journal=Science |volume=13 |issue=123 |pages=635-6 |year=1956 |pmid=13311516}}</ref>
| | ==[[Galactosemia overview|Overview]]== |
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| Its incidence is about 1 per 47,000 births (classic type). It is much rarer in Japan and much more common in Italy, specifically the traveler region.
| | ==[[Galactosemia historical perspective|Historical Perspective]]== |
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| ==Cause== | | ==[[Galactosemia classification|Classification]]== |
| [[Lactose]] in food (such as dairy products) is broken down by the body into [[glucose]] and galactose. | |
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| <gallery>
| | ==[[Galactosemia pathophysiology|Pathophysiology]]== |
| Image:Lactose(lac).png |[[Lactose]]
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| Image:Glucose wpmp.png|[[Glucose]]
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| </gallery>
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| In individuals with galactosemia, the enzymes needed for further metabolism of galactose are severely diminished or missing entirely, leading to toxic levels of galactose to build up in the blood, resulting in [[hepatomegaly]] (an enlarged [[liver]]), [[renal failure]], [[cataract]]s, and [[brain damage]]. Without treatment, mortality in infants with galactosemia is about 75%.
| | ==[[Galactosemia causes|Causes]]== |
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| ==Types== | | ==[[Differentiating Galactosemia from other diseases|Differentiating Galactosemia from other Diseases]]== |
| Galactose is converted into glucose by the action of three enzymes, known as the Leloir pathway. Accordingly, there are 3 known types of Galactosemia; type 1, 2 and 3:
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| {| class="wikitable"
| | ==[[Galactosemia epidemiology and demographics|Epidemiology and Demographics]]== |
| | '''Type''' ||'''[[Diseases Database]]''' || '''[[OMIM]]''' || '''Gene ''' || '''[[Locus (genetics)|Locus]]''' || '''Enzyme''' || '''Name'''
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| |Type 1|| {{DiseasesDB2|5056}} || {{OMIM2|230400}} || {{Gene|GALT}} || 9p13|| [[galactose-1-phosphate uridyl transferase]] || [[classic galactosemia]]
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| |Type 2|| {{DiseasesDB2|29829}} ||{{OMIM2|230200}} || {{Gene|GALK1}} || 17q24|| [[galactokinase]] || [[galactokinase deficiency]]
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| |Type 3||{{DiseasesDB2|29842}} || {{OMIM2|230350}}|| {{Gene|GALE}} || 1p36-p35 || [[UDP galactose epimerase]] || galactose epimerase deficiency, UDP-Galactose-4-epimerase deficiency
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| |}
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| The order of these three types is not the same as the order that the enzymes are encountered by galactose on its metabolic path (which is closer to GALK, GALT, and then GALE, though many variations can occur.)
| | ==[[Galactosemia risk factors|Risk Factors]]== |
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| | ==[[Galactosemia screening|Screening]]== |
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| | ==[[Galactosemia natural history, complications and prognosis|Natural History, Complications and Prognosis]]== |
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| ==Diagnosis== | | ==Diagnosis== |
| Infants are now routinely screened for galactosemia in the United States, and the diagnosis is made while the person is still an infant.
| | [[Galactosemia history and symptoms|History and Symptoms]] | [[Galactosemia physical examination|Physical Examination]] | [[Galactosemia laboratory findings|Laboratory Findings]] | [[Galactosemia electrocardiogram|Electrocardiogram]] | [[Hashiomoto's thyroiditis chest x ray|Chest X Ray]] | [[Galactosemia CT|CT]] | [[Galactosemia MRI|MRI]] | [[Galactosemia echocardiography or ultrasound|Echocardiography or Ultrasound]] | [[Galactosemia other imaging findings|Other Imaging Findings]] | [[Galactosemia other diagnostic studies|Other Diagnostic Studies]] |
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| ==Treatment== | | ==Treatment== |
| The only treatment for classic galactosemia is eliminating lactose and galactose from the diet. Even with an early diagnosis and a restricted diet, however, some individuals with galactosemia experience long-term complications such as speech difficulties, [[learning disabilities]], neurological impairment (e.g. tremors, etc), and in girls, ovarian failure. These complications are treated if they appear in a manner similar to the way they would be treated in a non-galactosemic. Such complications have not been associated with Duarte galactosemia, and many individuals with Duarte galactosemia do not need to restrict their diet at all. Infants with classic galactosemia cannot be breast-fed due to lactose in human breast milk and are usually fed a soy-based formula.<ref>http://www.cdc.gov/breastfeeding/disease/contraindicators.htm</ref>
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| Galactosemia is sometimes confused with [[lactose intolerance]], but galactosemia is a more serious condition. Lactose intolerant individuals have an acquired or inherited shortage of the enzyme [[lactase]], and experience abdominal pains after ingesting dairy products, but no long-term effects. In contrast, a galactosemic individual who consumes galactose can cause permanent damage to their bodies.
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| Long term complication of galactosemia includes:
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| *Speech deficits
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| *[[Ataxia]]
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| *[[Dysmetria]]
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| *[[osteopenia|Diminished bone density]]
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| *[[Premature ovarian failure]]
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| *[[Cataract]]
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| For a thorough scientific overview of galactosemia, one can consult chapter 72 of OMMBID<ref>
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| [[Charles Scriver]], Beaudet, A.L., Valle, D., Sly, W.S., Vogelstein, B., Childs, B., Kinzler, K.W. (2006). [http://www.ommbid.com The Online Metabolic and Molecular Bases of Inherited Disease]. New York: McGraw-Hill. -
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| Free summaries of 255 chapters, full text through many universities and organizations. Also, the [http://books.mcgraw-hill.com/medical/ommbid/blog/ OMMBID blog].
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| </ref>. For more online resources and references, see [[inborn error of metabolism]]. <br />
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| ==References==
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| <references/>
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| == External links ==
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| * [http://www.galactosemia.com Galactosemia Resources and Information]
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| * [http://www.galactosemia.org Parents of Galactosemic Children, Inc. website]
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| * [http://www.rare-disorders.com/galactosemia.html What is Galactosemia?]
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| * [http://www.dshs.state.tx.us/newborn/handbook.shtm Galactosemia Handbook - A Guide for Families]
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| {{Endocrine, nutritional and metabolic pathology}}
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| {{SIB}}
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| [[de:Galaktosämie]] | | [[Galactosemia medical therapy|Medical Therapy]] | [[Galactosemia surgery|Surgery]] | [[Galactosemia primary prevention|Primary Prevention]] | [[Galactosemia secondary prevention|Secondary Prevention]] | [[Galactosemia cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Galactosemia future or investigational therapies|Future or Investigational Therapies]] |
| [[es:Galactosemia]] | |
| [[fr:Galactosémie]] | |
| [[nl:Galactosemie]] | |
| [[ja:ガラクトース血症]] | |
| [[pl:Galaktozemia]]
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| [[pt:Galactosemia]] | |
| [[ru:Галактоземия]]
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| [[sr:галактоземија]]
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| [[Category:Mature chapter]]
| | ==Case Studies== |
| [[Category:Inborn errors of metabolism]]
| | [[Galactosemia case study one|Case #1]] |
| [[Category:Genetic disorders]]
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| [[Category:Metabolic disorders]]
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| [[Category:Genetic Disease]] | |
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| | {{Metabolic pathology}} |
| | [[Category:Endocrinology]] |
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