Below you will find more information about Alcaptonuria from Medigest. If you believe that you are suffering from any of the symptoms of Alcaptonuria it is important that you obtain an accurate diagnosis from a medical professional to ensure that you obtain the correct medication or treatment for your condition. There are medical conditions that carry similar symptoms associated with Alcaptonuria and therefore the information provided by Medigest is offered as a guideline only and should never be used in preference to seeking professional medical advice. The information relating to Alcaptonuria comes from a third party source and Medigest will not be held liable for any inaccuracies relating to the information shown.


Alcaptonuria is more commonly known as black urine disease, which is very rare genetic disease that can be passed on as an autosomal recessive trait. The particular gene that causes this disorder is unable to break down some proteins known as phenylalanine and tyrosine that may be toxic to the human body. This condition is harmful to the bones and body tissues.


Alcaptonuria is typically diagnosed when an individual starts to suffer progressive arthritis, predominantly in the spine, experience joint discomfort as well ass unexplained discoloration of the skin. This disorder affects a great number of organ systems in the body.


To date, there is no existing treatment of alcaptonuria, although ascorbic acid is usually prescribed to prevent pigment deposits. The degenerative joint symptoms are treated as osteoarthritis.

Symptoms and Signs

Symptoms include skin pigmentations in body areas that are directly under sun exposure, brownish sweat and progressive and premature deterioration of the joints and bones. Pigmentation may also be deposited in the respiratory organs such as the bronchi, windpipe and larynx.


Alcaptonuria is caused by the mutation in the HGD gene. This particular gene produces an enzyme that helps break down amino acids into smaller molecule. Mutations prevent the production of this enzyme causing the buildup of homogentisic acid, which is also present in the patient's urine and causes it to turn black upon exposure to air.

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