Alkaptonuria is a rare genetic disorder that causes the body to be unable to break down certain amino acids. The condition is caused by a defect in an enzyme called homogentisic acid oxidase. This enzyme is needed to break down a type of amino acid called homogentisic acid. When this enzyme is not working properly, the homogentisic acid builds up in the body, leading to a range of problems.
The most common symptom of alkaptonuria is a darkening of the urine, which may become black or dark brown when exposed to air. This is caused by the buildup of homogentisic acid in the body, which is then excreted in the urine. Other symptoms include joint pain and stiffness, especially in the spine and hip joints. Over time, the joint pain can become more severe and can severely limit mobility. Alkaptonuria can also lead to a darkening of the skin, called ochronosis, as well as heart problems and kidney stones.
Treatment of alkaptonuria largely focuses on managing and controlling symptoms. Dietary changes are often recommended, such as avoiding foods high in homogentisic acid, such as soybeans and alfalfa. Pain medications, such as anti-inflammatories, can help manage joint pain and stiffness. In some cases, surgery may be necessary to correct joint damage caused by the condition.
There is currently no cure for alkaptonuria, but early detection and proper management of symptoms can help prevent long-term complications. If you or a loved one have been diagnosed with alkaptonuria, it is important to discuss treatment options with your healthcare provider.