Black Urine Disease

Black Urine Disease is also known as Alkaptonuria, as scientists never waste a a good opportunity to make something sound more interesting.

Black Urine Disease is rare (one in 250,000 people) inherited recessive genetic disease that results in a build-up of a substance in the blood called homogentisic acid, staining the tissues dark. In addition, the condition prevents the body from entirely breaking down two amino acids called tyrosine and phenylalanine that are responsible for body pigmentation. Homogentisic acid and its oxidized form alkapton are excreted in the urine, giving it an unusually dark color.

The accumulating homogentisic becomes overt in form of severe spondylosis, peripheral arthropathy, tendon rupture, bone osteoporosis as well as aortic valve stenosis and skin pigmentation, as well as precipitating as kidney stones and stones in other organs[1].

Symptoms of Black Urine Disease usually develop in people over 30 years old, although the dark discoloration of the urine is present from birth. Black Urine Disease seems more common in Slovakia and the Dominican Republic.

Apart from treatment of the complications (such as pain relief and joint replacement for the cartilage damage), the drug (read: herbicide) nitisinone has been found to suppress the production of homogentisic acid, and research is ongoing as to whether it can improve symptoms[2].

[1] Grosicka, Kucharz: Alkaptonuria in Wiadomości Lekarskie (Medical News) – 2009
[2] Häberle: Suitability of nitisinone for alkaptonuria in Lancet - 2020