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    It is possible that the main title of the report Alkaptonuria is not the name you expected.

    Disorder Subdivisions

    • None

    General Discussion

    Alkaptonuria is a rare genetic metabolic disorder characterized by the accumulation of homogentisic acid in the body. Affected individuals lack enough functional levels of an enzyme required to breakdown homogentisic acid. Affected individuals may have dark urine or urine that turns black when exposed to air. However, this change may not occur for several hours after urination and often goes unnoticed. Aside from dark urine that is present from infancy, affected individuals generally do not develop symptoms (asymptomatic) during infancy or childhood and often remain unaware of their condition until adulthood. Affected individuals eventually develop ochronosis, which is the bluish-black discoloration of connective and other tissue within the body. Affected individuals may develop discoloration of the skin overlying cartilage within the body such as over part of the outer ear. In some cases, the whites of the eyes (sclera) may also become discolored. In adulthood, affected individuals also develop progressive arthritis of the spine and large joints. The HDG gene codes for the enzyme required for the breakdown of homogentisic acid. Mutations in HDG cause alkaptonuria.

    Supporting Organizations

    AKU Society of North America

    10451 Roselle Street #300
    San Diego, CA 92121
    Tel: (800)549-8110
    Website: http://www.akusocietyna.org/

    Alkaptonuria Society

    66 Devonshire Road
    Cambridge, CB1 2BL
    United Kingdom
    Tel: +44 (0)1223 322897
    Email: info@alkaptonuria.info
    Website: http://www.akusociety.org/index.html

    CLIMB (Children Living with Inherited Metabolic Diseases)

    Climb Building
    176 Nantwich Road
    Crewe, CW2 6BG
    United Kingdom
    Tel: 4408452412173
    Fax: 4408452412174
    Email: enquiries@climb.org.uk
    Website: http://www.CLIMB.org.uk

    Genetic and Rare Diseases (GARD) Information Center

    PO Box 8126
    Gaithersburg, MD 20898-8126
    Tel: (301)251-4925
    Fax: (301)251-4911
    Tel: (888)205-2311
    Website: http://rarediseases.info.nih.gov/GARD/

    NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases

    Information Clearinghouse
    One AMS Circle
    Bethesda, MD 20892-3675
    Tel: (301)495-4484
    Fax: (301)718-6366
    Tel: (877)226-4267
    Email: NIAMSinfo@mail.nih.gov
    Website: http://www.niams.nih.gov/

    For a Complete Report

    This is an abstract of a report from the National Organization for Rare Disorders (NORD). For a full-text version of this report, go to www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".

    The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only.

    It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report.

    This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

    Last Updated:  7/1/2015
    Copyright  2014 National Organization for Rare Disorders, Inc.

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