Tyrosinemia
You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.
| Tyrosinemia Classification and external resources | |
 | |
|---|---|
| Tyrosine | |
| ICD-10 | E70.2 |
| ICD-9 | 270.2 |
| OMIM | 276700 276600 276710 |
| DiseasesDB | 13478 13486 29836 |
| eMedicine | ped/2339 |
| MeSH | D020176 |
|
WikiDoc Resources for Tyrosinemia | |
|
Articles | |
|---|---|
|
Most recent articles on Tyrosinemia Most cited articles on Tyrosinemia | |
|
Media | |
|
Powerpoint slides on Tyrosinemia | |
|
Evidence Based Medicine | |
|
Clinical Trials | |
|
Ongoing Trials on Tyrosinemia at Clinical Trials.gov Clinical Trials on Tyrosinemia at Google
| |
|
Guidelines / Policies / Govt | |
|
US National Guidelines Clearinghouse on Tyrosinemia
| |
|
Books | |
|
News | |
|
Commentary | |
|
Definitions | |
|
Patient Resources / Community | |
|
Patient resources on Tyrosinemia Discussion groups on Tyrosinemia Patient Handouts on Tyrosinemia Directions to Hospitals Treating Tyrosinemia Risk calculators and risk factors for Tyrosinemia
| |
|
Healthcare Provider Resources | |
|
Causes & Risk Factors for Tyrosinemia | |
|
Continuing Medical Education (CME) | |
|
International | |
|
| |
|
Businness | |
|
Experimental / Informatics | |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Phone:617-525-6884
Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [2] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.
Tyrosinemia (or "Tyrosinaemia") is an error of metabolism, usually inborn, in which the body can not effectively break down the amino acid tyrosine.
Tyrosinemia is inherited in an autosomal recessive pattern. There are three types of tyrosinemia, each with distinctive symptoms and caused by the deficiency of a different enzyme.
Types
Type I tyrosinemia
Type I tyrosinemia (Online 'Mendelian Inheritance in Man' (OMIM) 276700) is the most severe form of this disorder and is caused by a shortage of the enzyme fumarylacetoacetate hydrolase (EC 3.7.1.2), encoded by the gene FAH found on chromosome number 15.
Fumarylacetoacetate hydrolase is the last in a series of five enzymes needed to break down tyrosine. Symptoms of type I tyrosinemia usually appear in the first few months of life and include failure to gain weight and grow at the expected rate (failure to thrive), diarrhea, vomiting, yellowing of the skin and whites of the eyes (jaundice), cabbagelike odor, and increased tendency to bleed (particularly nosebleeds).
Type I tyrosinemia can lead to liver and kidney failure, problems affecting the nervous system, and an increased risk of liver cancer.
Worldwide, type I tyrosinemia affects about 1 person in 100,000. This type of tyrosinemia is much more common in Quebec, Canada. The overall incidence in Quebec is about 1 in 16,000 individuals. In the Saguenay-Lac-Saint-Jean region of Quebec, type 1 tyrosinemia affects 1 person in 1,846.
Type II tyrosinemia
Type II tyrosinemia (Online 'Mendelian Inheritance in Man' (OMIM) 276600) is caused by a deficiency of the enzyme tyrosine aminotransferase (EC 2.6.1.5), encoded by the gene TAT.
Tyrosine aminotransferase is the first in a series of five enzymes that converts tyrosine to smaller molecules, which are excreted by the kidneys or used in reactions that produce energy. This form of the disorder can affect the eyes, skin, and mental development. Symptoms often begin in early childhood and include excessive tearing, abnormal sensitivity to light (photophobia), eye pain and redness, and painful skin lesions on the palms and soles. About half of individuals with type II tyrosinemia are also mentally retarded. Type II tyrosinemia occurs in fewer than 1 in 250,000 individuals.
Type III tyrosinemia
Type III tyrosinemia (Online 'Mendelian Inheritance in Man' (OMIM) 276710) is a rare disorder caused by a deficiency of the enzyme 4-hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27), encoded by the gene HPD. This enzyme is abundant in the liver, and smaller amounts are found in the kidneys. It is one of a series of enzymes needed to break down tyrosine.
Specifically, 4-hydroxyphenylpyruvate dioxygenase converts a tyrosine byproduct called 4-hydroxyphenylpyruvate to homogentisic acid. Characteristic features of type III tyrosinemia include mild mental retardation, seizures, and periodic loss of balance and coordination (intermittent ataxia). Type III tyrosinemia is very rare; only a few cases have been reported.
Treatment
Treatment varies depending on the specific type. A low protein diet may be required in the management of tyrosinemia. Recent experience with NTBC has shown to be very effective.
See also
- Alkaptonuria
- Ochronosis
- For a thorough scientific overview of hypertyrosinemia, one can consult chapter 79 of OMMBID[1]. For more online resources and references, see inborn errors of metabolism.
External links
- University of Washington
- Liver Families - pediatric liver support group
References
- ↑ Charles Scriver, Beaudet, A.L., Valle, D., Sly, W.S., Vogelstein, B., Childs, B., Kinzler, K.W. (Accessed 2007). The Online Metabolic and Molecular Bases of Inherited Disease. New York: McGraw-Hill. - Summaries of 255 chapters, full text through many universities. There is also the OMMBID blog.
Acknowledgement and Attribution Regarding Sources of Content
Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .
