alkaptonuria

n. disease characterized by alkapton in the urine

Alkaptonuria (black urine disease, alcaptonuria or ochronosis) is a rare inherited genetic disorder of tyrosine metabolism. This is an autosomal recessive trait that is caused by a defect in the enzyme homogentisic acid oxidase . The enzyme normally breaks down a toxic tyrosine byproduct, homogentisic acid (also called alkapton), which is harmful to bones and cartilage and is excreted in urine.
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Alkaptonuria /al·kap·ton·uria/ an autosomal recessive aminoacidopathy with accumulation of homogentisic acid in urine, ochronosis, and arthritis. [more]Alkaptonuria - Community and Resources

Noun
1. a rare recessive metabolic anomaly marked by ochronosis and the presence of alkapton in the urine
(synonym) alcaptonuria
(hypernym) metabolic disorder

noun
hereditary condition where dark pigment is present in the urine