homogentisic acid
Quick Summary
Homogentisic acid is a chemical compound that plays a role in the metabolic pathway of amino acids tyrosine and phenylalanine. In individuals with a rare inherited disorder called alkaptonuria, the enzyme homogentisate 1,2-dioxygenase is inactive due to a gene mutation. This leads to a buildup and oxidation of homogentisic acid, causing urine to turn black when exposed to air.1
While alkaptonuria has no clinical symptoms until adulthood, the pigment deposits can cause connective tissues to become brittle, leading to degenerative joint disease. In tyrosinemia, another inherited disorder, the enzyme p-hydroxyphenylpyruvic acid oxidase is inactive, preventing the conversion of p-(p-)hydroxyphenylpyruvic acid to homogentisic acid. This results in increased tyrosine levels in the blood and urine, kidney defects, and liver damage.12
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renal systemVolume and composition…identified by the presence of homogentisic acid in the urine, is due to lack of the enzyme that catalyzes the oxidation of homogentisic acid; deposits of the acid in the tissues may cause chronic arthritis or spinal disease. Other such disorders are cystinuria, the presence of the amino acid cystine…
Read More…identified by the presence of homogentisic acid in the urine, is due to lack of the enzyme that catalyzes the oxidation of homogentisic acid; deposits of the acid in the tissues may cause chronic arthritis or spinal disease. Other such disorders are cystinuria, the presence of the amino acid cystine…
Read More- connective tissue diseaseHereditary disorders of connective tissue
…in an abnormal accumulation of homogentisic acid, a normal intermediate in the metabolism of the amino acid tyrosine. Some homogentisic acid is excreted in the urine, to which, upon alkalinization and oxidation, it imparts a black colour. The remainder is deposited in cartilage and, to a lesser degree, in the…
Read More…in an abnormal accumulation of homogentisic acid, a normal intermediate in the metabolism of the amino acid tyrosine. Some homogentisic acid is excreted in the urine, to which, upon alkalinization and oxidation, it imparts a black colour. The remainder is deposited in cartilage and, to a lesser degree, in the…
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