What is black urine disease?
Black urine disease also called alkaptonuria or homogentisuria, it is a rare, autosomal recessive condition, secondary to a defect in the enzyme homogentisate 1,2-dioxygenase, which is involved in the degradation of tyrosine.
As a result, homogentisic acid is formed and excreted in the urine in excessive amounts.
Excessive homogentisic acid causes ochronosis, pigmented sclerae, aortic and mitral regurgitation, and formation of kidney stones and prostatic stones. Of interest, most cases in the literature are in patients who are either from Slovakia or the Dominican Republic.
