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    Hunter Syndrome

    Important
    It is possible that the main title of the report Hunter Syndrome is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.

    Synonyms

    • MPS Disorder II
    • MPS II
    • Mucopolysaccharidosis Type II

    Disorder Subdivisions

    • MPS IIA
    • MPS IIB

    General Discussion

    Hunter syndrome, also known as mucopolysaccharidosis II, is a rare inborn error of metabolism characterized by inadequate production of an enzyme known as iduronate sulfatase, which is needed to break down complex sugars produced in the body. Symptoms include growth delay, joint stiffness, and coarsening of facial features. In severe cases, patients experience respiratory and cardiac problems, enlargement of the liver and spleen, and neurological deficits. The disorder can lead to premature death in severe cases.

    Hunter syndrome is one of a group of hereditary metabolic diseases known as the mucopolysaccharidoses (MPS), which in turn are part of a group known as lysosomal storage disorders. Lysosomes function as the primary digestive units within cells. Enzymes within lysosomes break down or digest particular nutrients, such as certain carbohydrates and fats. In individuals with MPS disorders, including Hunter syndrome, deficiency or improper functioning of lysosomal enzymes leads to an abnormal accumulation of certain complex carbohydrates in cells within various tissues, such as the skeleton, joints, brain, spinal cord, heart, spleen, or liver.

    Initial symptoms and findings associated with Hunter syndrome usually become apparent in children from two to four years of age. Such abnormalities may include progressive growth delays, resulting in short stature; joint stiffness, with associated restriction of movements; and coarsening of facial features, including thickening of the lips, tongue, and nostrils. Affected children may also have an abnormally large head (macrocephaly), a short neck and broad chest, delayed tooth eruption, progressive hearing loss, and enlargement of the liver and spleen (hepatosplenomegaly). Two relatively distinct clinical forms of Hunter syndrome have been recognized. In the late-onset, mild form of the disease (MPS IIB), intelligence may be normal or only slightly impaired. However, in the early-onset, more severe form (MPS IIA), profound mental retardation may be apparent by late childhood. In addition, slower disease progression tends to occur in those with the mild form of the disorder.

    Hunter syndrome is inherited as an X-linked recessive trait. Mild and severe forms of the disorder result from changes (mutations) of a gene (i.e., IDS gene) that regulates production of the iduronate sulfatase enzyme. The IDS gene is located on the long arm (q) of chromosome X (Xq28).

    Resources

    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
    Internet: http://www.CLIMB.org.uk

    Vaincre Les Maladies Lysosomales
    2 Ter Avenue
    Massy, 91300
    France
    Tel: 0169754030
    Fax: 0160111583
    Email: accueil@vml-asso.org
    Internet: http://www.vml-asso.org

    March of Dimes Birth Defects Foundation
    1275 Mamaroneck Avenue
    White Plains, NY 10605
    Tel: (914)997-4488
    Fax: (914)997-4763
    Tel: (888)663-4637
    Email: Askus@marchofdimes.com
    Internet: http://www.marchofdimes.com

    The Arc
    1825 K Street NW, Suite 1200
    Washington, DC 20006
    Tel: (202)534-3700
    Fax: (202)534-3731
    Tel: (800)433-5255
    TDD: (817)277-0553
    Email: info@thearc.org
    Internet: http://www.thearc.org

    National MPS Society, Inc.
    PO Box 14686
    Durham, NC 27709
    Tel: (919)806-0101
    Fax: (919)806-2055
    Tel: (877)677-1001
    Email: info@mpssociety.org
    Internet: http://www.mpssociety.org

    NIH/National Institute of Diabetes, Digestive & Kidney Diseases
    Office of Communications & Public Liaison
    Bldg 31, Rm 9A06
    31 Center Drive, MSC 2560
    Bethesda, MD 20892-2560
    Tel: (301)496-3583
    Email: NDDIC@info.niddk.nih.gov
    Internet: http://www2.niddk.nih.gov/

    Society for Mucopolysaccharide Diseases
    MPS House
    Repton Place
    White Lion Road
    Amersham
    Buckinghamshire, HP7 9LP
    United Kingdom
    Tel: 08453899901
    Fax: 08453899902
    Email: mps@mpssociety.co.uk
    Internet: http://www.mpssociety.co.uk

    Canadian Society for Mucopolysaccharide and Related Diseases, Inc.
    PO Box 30034
    RPO Parkgate
    North Vancouver
    British Columbia, V7H 2Y8
    Canada
    Tel: 6049245130
    Fax: 6049245131
    Tel: 8006671846
    Email: info@mpssociety.ca
    Internet: http://www.mpssociety.ca

    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
    TDD: (888)205-3223
    Internet: http://rarediseases.info.nih.gov/GARD/

    Madisons Foundation
    PO Box 241956
    Los Angeles, CA 90024
    Tel: (310)264-0826
    Fax: (310)264-4766
    Email: getinfo@madisonsfoundation.org
    Internet: http://www.madisonsfoundation.org

    Let Them Hear Foundation
    1900 University Avenue, Suite 101
    East Palo Alto, CA 94303
    Tel: (650)462-3174
    Fax: (650)462-3144
    Email: info@letthemhear.org
    Internet: http://www.letthemhear.org

    Hide & Seek Foundation for Lysosomal Disease Research
    6475 East Pacific Coast Highway Suite 466
    Long Beach, CA 90803
    Tel: (877)621-1122
    Fax: (866)215-8850
    Email: info@hideandseek.org
    Internet: http://www.hideandseek.org

    Proyecto Pide un Deseo México, i.a.p.
    Altadena #59-501 col. Napoles
    delegacion Benito Juarez
    03810 Mexico D.F.
    Tel: 55 5543-2447
    Fax: 55-5543-5450
    Email: prayecto.pdeundese.mexico@gmail.com
    Internet: http://www.pideundeseo.org

    For a Complete Report:

    This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, 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. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.

    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.

    For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site www.rarediseases.org or email orphan@rarediseases.org

    Last Updated: 8/17/2007
    Copyright 1986, 1987, 1988, 1990, 1999, 2000, 2001, 2002, 2004, 2006, 2007 National Organization for Rare Disorders, Inc.

    WebMD Medical Reference from the National Organization for Rare Disorders

    Last Updated: May 28, 2015
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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