Alkaptonuria - Symptom
AKU; Alcaptonuria; Homogentisic acid oxidase deficiency; Alcaptonuric ochronosis
Urine in an infant's diaper may darken and can turn almost black after several hours. However, many persons with this condition may not know they have it until mid-adulthood (around age 40), when joint and other problems occur.
Symptoms may include:
- Arthritis (especially of the spine) that gets worse over time
- Darkening of the ear
- Dark spots on the white of the eye (sclera) and cornea
Signs and tests:
A urine test (urinalysis) is done to test for alkaptonuria. If ferric chloride is added to the urine, it will turn the urine a black color in patients with this condition.
- Reviewed last on: 5/15/2011
- Chad Haldeman-Englert, MD, Wake Forest School of Medicine, Department of Pediatrics, Section on Medical Genetics, Winston-Salem, NC. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
Chakrapani A, Holme E. Disorders of tyrosine metabolism. In: Fernandes J, Saudubray J-m, van den Berghe G, Walter JH, eds. Inborn Metabolic Diseases: Diagnosis and Treatment. 4th ed. New York, NY: Springer;2006:chap 18.
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