Alkaptonuria
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.
| Alkaptonuria Classification and external resources | |
 | |
|---|---|
| Homogentisic acid | |
| ICD-10 | E70.2 |
| ICD-9 | 270.2 |
| OMIM | 203500 |
| DiseasesDB | 409 |
| eMedicine | ped/64 |
| MeSH | D000474 |
|
WikiDoc Resources for Alkaptonuria | |
|
Articles | |
|---|---|
|
Most recent articles on Alkaptonuria Most cited articles on Alkaptonuria | |
|
Media | |
|
Powerpoint slides on Alkaptonuria | |
|
Evidence Based Medicine | |
|
Clinical Trials | |
|
Ongoing Trials on Alkaptonuria at Clinical Trials.gov Clinical Trials on Alkaptonuria at Google
| |
|
Guidelines / Policies / Govt | |
|
US National Guidelines Clearinghouse on Alkaptonuria
| |
|
Books | |
|
News | |
|
Commentary | |
|
Definitions | |
|
Patient Resources / Community | |
|
Patient resources on Alkaptonuria Discussion groups on Alkaptonuria Patient Handouts on Alkaptonuria Directions to Hospitals Treating Alkaptonuria Risk calculators and risk factors for Alkaptonuria
| |
|
Healthcare Provider Resources | |
|
Causes & Risk Factors for Alkaptonuria | |
|
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.
Alkaptonuria (black urine disease, alcaptonuria or ochronosis) is a rare inherited genetic disorder of tyrosine metabolism. This is an autosomal recessive trait that is caused by a defect in the enzyme homogentisic acid oxidase (EC 1.13.11.5). The enzyme normally breaks down a toxic tyrosine byproduct, homogentisic acid (also called alkapton), which is harmful to bones and cartilage and is excreted in urine.
Symptoms
A distinctive characteristic of alkaptonuria is that ear wax exposed to air turns red or black (depending on diet) after several hours because of the accumulation of homogentisic acid. Similarly, urine exposed to air can become dark; this is useful for diagnosising young children using diapers. In adulthood, but usually not before age forty, persons suffering from alkaptonuria develop progressive arthritis (especially of the spine), due to the long-term buildup of homogentisate in bones and cartilage. The urine is malodorous.
Diagnosis
Presumptive diagnosis can be made by adding sodium or potassium hydroxide to urine and observing the formation of a dark brown to black pigment on the surface layer of urine within 30 minutes to 1 hour. Diagnosis can be confirmed by demonstrating the presence of homogentisic acid in the urine. This may be done by paper chromatography and thin-layer chromatography.
Treatment
Prevention is not possible and the treatment is aimed at ameliorating symptoms. Reducing intake of the amino acids phenylalanine and tyrosine to the minimum required to sustain health (phenylalanine is an essential amino acid) can help slow the progression of the disease.
History
Alkaptonuria was one of the four diseases described by Sir Archibald Edward Garrod, as being the result of the accumulation of intermediates due to metabolic deficiencies. He linked ochronosis with the accumulation of alkaptans in 1902,[1] and his views on the subject were summarised in a 1908 Croonian lecture at the Royal College of Physicians.[2] While Garrod identified it as a recessive condition, its genetic basis was not elucidated until 1996, when it was linked to HGO mutations.[3]
See also
References
- ↑ Garrod AE (1902). The incidence of alkaptonuria: a study in clinical individuality. Lancet 2: 1616−1620. Reproduced in Yale J Biol Med 75:221-31 (2002). PMID 12784973.
- ↑ Garrod AE (1908). The Croonian lectures on inborn errors of metabolism: lecture II: alkaptonuria. Lancet 2: 73–79.
- ↑ Fernández-Cañón JM, Granadino B, Beltrán-Valero de Bernabé D, et al (1996). "The molecular basis of alkaptonuria". Nat. Genet. 14 (1): 19-24. doi:10.1038/ng0996-19. PMID 8782815.
External links
de:Alkaptonurie fa:آلکاپتونوری fr:Alcaptonurie hu:Alkaptonuria nl:Alkaptonurie
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 .
