Genetic counseling is the process of providing individuals Alkaptonuria is inherited in an autosomal recessive manner. – ALKAPTONURIA; AKU – HOMOGENTISIC ACID OXIDASE in the homogentisate 1,2-dioxygenase gene (HGD; ) on chromosome 3q Alkaptonuria is a rare inherited genetic disorder in which the body cannot process the amino acids phenylalanine and tyrosine, which occur in protein.

Author: Bagami Shalar
Country: Bermuda
Language: English (Spanish)
Genre: History
Published (Last): 17 August 2004
Pages: 299
PDF File Size: 19.23 Mb
ePub File Size: 19.6 Mb
ISBN: 879-6-51406-831-9
Downloads: 4063
Price: Free* [*Free Regsitration Required]
Uploader: Diktilar

With echocardiography, sound waves alkaptonuriz bounced off the heart echoesenabling physicians to study cardiac function and motion. Homogentisic acid and its oxidized form alkapton are excreted in the urine, giving it an unusually dark color. Different mutations may affect the structure, function, or solubility of the enzyme.

For more information on these disorders, choose the specific disorder name as your search term in the Rare Disease Database. Ear cartilage pigmentation is seen in the concha and antihelix. Nitisinone, which received orphan drug status in from the Food and Drug Administration FDAhas been approved for the treatment of a metabolic disorder known as tyrosinemia. Dietary restriction of phenylalanine and tyrosine has been proposed to reduce the production of HGA, but severe restriction of these amino acids is not practical in the long term and may be dangerous.

After the third decade, unusual pigmentation of the sclera and the skin overlying cartilage begins to be observed, as well as muscular-skeletal symptoms such as back pain and stiffness.


The tyrosine degradation pathway. Effects of ascorbic acid in alkaptonuria: The typical age at requiring joint replacement surgery is 50—55 genetivs.

Molecular Genetics of Alkaptonuria

By using this site, you agree to the Terms of Use and Privacy Policy. Submit a note to the editor about this article by filling in the form below. Dietary restrictions have generally proven ineffective. He said that it is to be hoped that some, perhaps all, of the adverse effects of alkaptonuria can be prevented by new molecular therapeutic approaches; however, trading alkaptonuric problems for even more serious metabolic disturbances because of the pronounced toxicity of the later tyrosine metabolites is not an acceptable alternative.


Expert curators review the literature and organize it to facilitate your work. Offspring of a proband. Nitisinone has been used for some time at much higher doses in the treatment of type I tyrosinemia.

Alkaptonuria has been reported in all ethnic groups. Alkaptonufia on ochronosis in this monogenic disease can help to elucidate the molecular pathogenesis of the more common varieties of osteoarthritis, particularly the biochemical and structural changes at its genettics stages.

D ICD – Recessive genetic disorders occur when an individual inherits the same abnormal gene for the same trait from each parent. Scientific World Journal Pigment deposition in the heart valves and blood vessels leads to aortic or mitral valve calcification with stenosis or regurgitation and occasionally aortic dilatation. Fortunately this is a thing of the past.

Alkaptonuria – GeneReviews® – NCBI Bookshelf

Although homogentisic acid is rapidly cleared from the body by the kidneys, it also slowly accumulates in the various tissues of the body, especially connective tissue such as cartilage. Studying 4 alkaptonuria patients from Slovakia, where alkaptonuria has a notably high frequency, Gehrig et al.


PMC ] [ PubMed: Affected Populations Alkaptonuria affects males and females in equal numbers, although symptoms tend to develop sooner and become more severe in males.

In individuals over 40, echocardiography may be recommended to detect potential cardiac complications such as aortic dilation or calcification or regurgitation of the aortic or mitral valves. Ochronosis resulting from alkaptonuria may be confused with acquired, reversible pigmentary changes following prolonged use of carbolic acid dressings for chronic cutaneous ulcers [ La Du ].

Symptoms of the following disorders can be similar to those of alkaptonuria. Retrieved 17 April No ophthalmic, neurologic, or severe dermatologic complications were observed. Ochronotic prostate stones appear on radiography; kidney stones can be identified by ultrasonography and helical abdominal CT.

Severe restriction of protein intake is required and has proven difficult for individuals to maintain over a long period of time.

For a detailed summary of gene and protein information, see Table AGene. American Journal of Human Genetics The code used for the mutations is depicted in the venetics inset.

Alkaptonuria is a rare genetic metabolic disorder characterized by the accumulation of homogentisic acid in the body.