Related to the congenital deficiency of homogentisic acid oxidase.
Homogentisic acid oxidase is an enzyme used in the degradation of tyrosine.
Homogentisic acid dioxygenase converts homogentisic acid to maleylacetoacetic acid.
Results in the buildup of homogenization that polymerizes to black brown pigment.
Dark pigment accumulates in connective tissues, including cartilage.
Patient presents in adulthood with arthritis.
May turn sweat and urine turn black upon standing.
Process may be diagnosed by allowing urine to stand and noting color change.
Diagnosis can be made by measuring urine homogentistic acid.
No specific beneficial treatment.