alkaptonuria /alkap′tōno͝or″ē·ə/ [Ar, al + galiy + Gk, haptein, to possess, ouron urine] , a rare inherited disorder marked by the excretion of large amounts of homogentisic acid in the urine, which is the result of the incomplete metabolism of the amino acids tyrosine and phenylalanine. The presence of the acid is indicated by darkening of urine when exposed to air or by brown or blue discoloration of the ears or eyes. Other indications are restricted joint mobility, kidney stones, and vascular hypertension. See also ochronosis. −alkaptonuric, adj.
