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 urine exposed to air turns dark (or black) after several hours because of the homogentisic acid. In adulthood, persons suffering from alkaptonuria develop progressive arthritis (especially of the spine), due to its degenerative effects on bones and cartilage.

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 (Seegmiller, 1998).

Treatment

Prevention is not possible and the treatment is aimed at ameliorating symptoms.

Read more at Wikipedia.org

• [List your site here Free!]


	Cutaneous markers in Ochronosis.(Letter To Editor) : An article from: Indian Journal of Medical Sciences $5.95	Lichen amyloidosus: A study of clinical, histopathologic and immunofluorescence findings in 30 cases.(Studies) : An article from: Indian Journal of Dermatology, Venereology and Leprology $5.95


Alkaptonuria diagnosed by flexible bronchoscopy A 68-year-old white man was evaluated for failure to wean from mechanical ventilation after cardiac surgery. Bronchoscopy performed prior to percutaneous ... From CHEST, 11/1/05 by Joseph G. Parambil

Spontaneous tendon ruptures in alkaptonuria/Author's reply Sir, We read with interest the article by Manoj Kumar and Rajasekaran1 in the August 2003 issue entitled 'Spontaneous tendon ruptures in alkaptonuria'. From Journal of Bone and Joint Surgery, 9/1/04 by Logani, V

Spontaneous tendon ruptures in alkaptonuria Received 5 July 2002; Accepted after revision 16 December 2002 Ochronosis, the musculoskeletal manifestation of alkaptonuria, is known to lead to degenerative ... From Journal of Bone and Joint Surgery, 8/1/03 by Kumar, R V Manoj

Dura mater involvement in ochronosis (alkaptonuria) Clinical manifestations of alkaptonuria have been well described and are most commonly characterized by ochronosis or pigmentation of connective tissue. From Archives of Pathology & Laboratory Medicine, 7/1/01 by Liu, Wendy

Urinalysis Urinalysis is a diagnostic physical, chemical, and microscopic examination of a urine sample (specimen). Specimens can be obtained by normal emptying of ... From Gale Encyclopedia of Medicine, 4/6/01 by Maureen Haggerty

Exogenous ochronosis Abstract We describe a case of a 70-year-old woman who had been using a skin-lightening cream containing hydroquinone for a previous diagnosis of melasma. She presented a hyperpigmentation predom From Journal of Drugs in Dermatology, 1/1/06 by M. Huerta Brogeras

Pharmacogenomics: the promise of personalized medicine - Focus: pharmacogenomics Imagine being able to walk into your doctors office and present a "smart card" encoded either with the sequence of your genome itself or with an access ... From Environmental Health Perspectives, 8/15/03 by Ernie Hood

A Revolution in Genetics: Changing Medicine, Changing Lives The sequencing of the human genome is only the tip of the iceberg. It is the beginning of a revolution that many predict will transform medicine. How ... From Physician Executive, 3/1/01 by Kent Bottles

Home

Contact

Resources

Exchange Links

ebay