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SGSH gene

N-sulfoglucosamine sulfohydrolase

Normal Function

The SGSH gene provides instructions for producing an enzyme called sulfamidase. This enzyme is located in lysosomes, compartments within cells that digest and recycle different types of molecules. Sulfamidase is involved in the step-wise breakdown of large molecules called glycosaminoglycans (GAGs). GAGs are composed of sugar molecules that are linked together to form a long string. To break down these large molecules, individual sugars are removed one at a time from one end of the molecule. Sulfamidase removes a chemical group known as a sulfate from a sugar called glucosamine when it is at the end of the GAG chain.

Health Conditions Related to Genetic Changes

Mucopolysaccharidosis type III

More than 80 mutations in the SGSH gene have been found to cause mucopolysaccharidosis type IIIA (MPS IIIA). Most of these mutations change single DNA building blocks (nucleotides) in the gene. All of the mutations that cause MPS IIIA reduce or eliminate the function of sulfamidase.

The lack of sulfamidase activity disrupts the breakdown of a subset of GAGs called heparan sulfate. As a result, partially broken down heparan sulfate accumulates within lysosomes. Researchers believe that the accumulation of GAGs interferes with the functions of other proteins inside the lysosomes and disrupts the normal functions of cells. It is unknown why the buildup of heparan sulfate mostly affects the central nervous system in MPS IIIA.

More About This Health Condition

Other Names for This Gene

  • heparan N-sulfatase
  • heparan sulfate sulfatase
  • HSS
  • N-sulphoglucosamine sulphohydrolase
  • N-sulphoglucosamine sulphohydrolase precursor
  • SFMD
  • sulfamidase
  • sulfoglucosamine sulfamidase
  • sulphamidase

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases


  • Meyer A, Kossow K, Gal A, Steglich C, Muhlhausen C, Ullrich K, Braulke T, Muschol N. The mutation p.Ser298Pro in the sulphamidase gene (SGSH) is associated with a slowly progressive clinical phenotype in mucopolysaccharidosis type IIIA (Sanfilippo A syndrome). Hum Mutat. 2008 May;29(5):770. doi: 10.1002/humu.20738. Citation on PubMed
  • Muschol N, Storch S, Ballhausen D, Beesley C, Westermann JC, Gal A, Ullrich K, Hopwood JJ, Winchester B, Braulke T. Transport, enzymatic activity, and stability of mutant sulfamidase (SGSH) identified in patients with mucopolysaccharidosis type III A. Hum Mutat. 2004 Jun;23(6):559-66. doi: 10.1002/humu.20037. Citation on PubMed
  • Valstar MJ, Ruijter GJ, van Diggelen OP, Poorthuis BJ, Wijburg FA. Sanfilippo syndrome: a mini-review. J Inherit Metab Dis. 2008 Apr;31(2):240-52. doi: 10.1007/s10545-008-0838-5. Epub 2008 Apr 4. Citation on PubMed

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.