黑尿症（Alkaptonuria，AKU）是一种罕见的遗传性疾病，和酪氨酸和苯丙氨酸的代谢障碍有关，是一种体染色体隐性遗传，具有无法合成尿黑酸氧化酶的缺陷，这种酵素可降解有毒性的尿黑酸，这种酪氨酸副产物，会使软骨区变成黑色，例如耳朵、眼睛。

医学导航：遗传代谢缺陷

代谢、k,c/g/r/p/y/i,f/h/s/l/o/e,a/u,n,m

k,cgrp/y/i,f/h/s/l/o/e,au,n,m,人名体征

药物(A16/C10)、中间产物(k,c/g/r/p/y/i,f/h/s/o/e,a/u,n,m)

Alkaptonuria (black urine disease, black bone disease, or alcaptonuria) is a rare inherited genetic disorder in which the body cannot process the amino acids phenylalanine and tyrosine, which occur in protein. It is caused by a mutation in the HGD gene for the enzyme homogentisate 1,2-dioxygenase (EC1.13.11.5); if a person inherits abnormal copies from each parent (it is a recessive condition) the body accumulates an intermediate substance called homogentisic acid in the blood and tissues. Homogentisic acid and its oxidated form alkapton are excreted in the urine, giving it an unusually dark color. The accumulating homogentisic acid causes damage to cartilage (ochronosis, leading to osteoarthritis) and heart valves as well as precipitating as kidney stones and stones in other organs. Symptoms usually develop in people over thirty years old, although the dark discoloration of the urine is present from birth.