Tags: Disease.
Alkaptonuria (black urine disease or alcaptonuria) is a rare inherited genetic disorder of phenylalanine and tyrosine metabolism. This is an autosomal recessive condition that is due to a defect in the enzyme homogentisate 12-dioxygenase (EC 1.13.11.5) which participates in the degradation of tyrosine. As a result homogentisic acid and its oxide called alkapton accumulate in the blood and are excreted in urine in large amounts (hence -uria).
