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

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.

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Alkaptonuria Overview

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Alkaptonuria Treatment

Review Date: 04/15/2009
Reviewed By: Chad Haldeman-Englert, MD, Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)