Health Information



Sly Syndrome

National Organization for Rare Disorders, Inc.


It is possible that the main title of the report Sly 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.


  • Beta-Glucuronidase Deficiency
  • MPS Disorder, type VII
  • mucopolysaccharidosis type VII
  • GUSB deficiency

Disorder Subdivisions

  • None

General Discussion

Mucopolysaccharidoses, which are also known as mucopolysaccharide storage (MPS) diseases, are a group of rare genetic disorders caused by the deficiency of one of ten specific lysosomal enzymes. The lysosomes are particles bound in membranes within cells that break down certain fats and carbohydrates (mucopolysaccharides) into simpler molecules. The accumulation of these large, undegraded mucopolysaccharides in the cells of the body causes a number of physical symptoms and abnormalities.

Sly syndrome (MPS-VII) is an MPS storage disease caused by a deficiency of the enzyme beta-glucuronidase that leads to an accumulation of dermatan sulfate (DS), heparan sulfate (HS) and chondroitin sulfate (CS) in many tissues and organs of the body including the central nervous system.

The clinical features of Sly syndrome vary from patient to patient, but all have short stature due to growth retardation, changes in bones visible on X-rays and some degree of mental retardation. Survival into adulthood is common with milder cases and osteoarthritis is a common complication.

The symptoms of Sly Syndrome are similar to those of Hurler Syndrome (MPS I) and the other Mucopolysaccharidoses. Symptoms may include mental retardation, short stature with an unusually short trunk, and/or abnormalities of the intestines, corneas of the eyes, and/or the skeletal system. Sly Syndrome is inherited as an autosomal recessive genetic trait.


CLIMB (Children Living with Inherited Metabolic Diseases)

Climb Building

176 Nantwich Road

Crewe, CW2 6BG

United Kingdom

Tel: 4408452412173

Fax: 4408452412174



Vaincre Les Maladies Lysosomales

2 Ter Avenue

Massy, 91300


Tel: 0169754030

Fax: 0160111583



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



National MPS Society, Inc.

PO Box 14686

Durham, NC 27709

Tel: (919)806-0101

Fax: (919)806-2055

Tel: (877)677-1001



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



Society for Mucopolysaccharide Diseases

MPS House

Repton Place

White Lion Road


Buckinghamshire, HP7 9LP

United Kingdom

Tel: 08453899901

Fax: 08453899902



Canadian Society for Mucopolysaccharide and Related Diseases, Inc.

PO Box 30034

RPO Parkgate

North Vancouver

British Columbia, V7H 2Y8


Tel: 6049245130

Fax: 6049245131

Tel: 8006671846



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


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



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 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 or email

Last Updated:  5/12/2008

Copyright  1986, 1987, 1988, 1990, 1994, 1995, 2003 National Organization for Rare Disorders, Inc.

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