National Organization for Rare Disorders, Inc.
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.
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).
CLIMB (Children Living with Inherited Metabolic Diseases)
- Climb Building
- 176 Nantwich Road
- Crewe, CW2 6BG
- United Kingdom
- Tel: 4408452412173
- Fax: 4408452412174
- Email: firstname.lastname@example.org
- Website: http://www.CLIMB.org.uk
Canadian Society for Mucopolysaccharide and Related Diseases, Inc.
- PO Box 30034
- RPO Parkgate
- British Columbia, V7H 2Y8
- Tel: 6049245130
- Fax: 6049245131
- Tel: 8006671846
- Email: email@example.com
- Website: 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
- Website: http://rarediseases.info.nih.gov/GARD/
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: firstname.lastname@example.org
- Website: http://www.hideandseek.org
Let Them Hear Foundation
- 1900 University Avenue, Suite 101
- East Palo Alto, CA 94303
- Tel: (650)462-3174
- Fax: (650)462-3144
- Email: email@example.com
- Website: http://www.letthemhear.org
March of Dimes Birth Defects Foundation
- 1275 Mamaroneck Avenue
- White Plains, NY 10605
- Tel: (914)997-4488
- Fax: (914)997-4763
- Website: http://www.marchofdimes.com
NIH/National Institute of Diabetes, Digestive & Kidney Diseases
- Office of Communications & Public Liaison
- Bldg 31, Rm 9A06
- Bethesda, MD 20892-2560
- Tel: (301)496-3583
- Email: NDDIC@info.niddk.nih.gov
- Website: http://www2.niddk.nih.gov/
National MPS Society, Inc.
- PO Box 14686
- Durham, NC 27709
- Tel: (919)806-0101
- Fax: (919)806-2055
- Tel: (877)677-1001
- Email: firstname.lastname@example.org
- Website: http://www.mpssociety.org
Proyecto Pide un Deseo México, i.a.p.
- Altadena #59-501
- Benito Juárez, 03810
- México, D.F.
- Tel: +52 55 5543-2447
- Fax: 55-5543-5450
- Email: email@example.com
- Website: http://www.pideundeseo.org
Society for Mucopolysaccharide Diseases
- MPS House
- Repton Place
- Buckinghamshire, HP7 9LP
- United Kingdom
- Tel: 8453899901
- Fax: 8453899902
- Email: firstname.lastname@example.org
- Website: http://www.mpssociety.co.uk
- 1825 K Street NW, Suite 1200
- Washington, DC 20006
- Tel: (202)534-3700
- Fax: (202)534-3731
- Tel: (800)433-5255
- Email: email@example.com
- Website: http://www.thearc.org
U.R. Our Hope
- P.O. Box 50152
- Austin, TX 78763
- Tel: (512)484-6227
- Email: firstname.lastname@example.org
- Website: http://www.urourhope.org
Vaincre Les Maladies Lysosomales
- 2 Ter Avenue
- Massy, 91300
- Tel: 169754030
- Fax: 160111583
- Email: email@example.com
- Website: http://www.vml-asso.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 firstname.lastname@example.org
Last Updated: 1/10/1970
Copyright 2007 National Organization for Rare Disorders, Inc.
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