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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed August 2010

What is the official name of the SGSH gene?

The official name of this gene is “N-sulfoglucosamine sulfohydrolase.”

SGSH is the gene's official symbol. The SGSH gene is also known by other names, listed below.

What is the normal function of the SGSH gene?

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.

How are changes in the SGSH gene related to health conditions?

mucopolysaccharidosis type III - caused by mutations in the SGSH gene

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.

Where is the SGSH gene located?

Cytogenetic Location: 17q25.3

Molecular Location on chromosome 17: base pairs 80,206,966 to 80,220,400

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The SGSH gene is located on the long (q) arm of chromosome 17 at position 25.3.

The SGSH gene is located on the long (q) arm of chromosome 17 at position 25.3.

More precisely, the SGSH gene is located from base pair 80,206,966 to base pair 80,220,400 on chromosome 17.

See How do geneticists indicate the location of a gene? ( in the Handbook.

Where can I find additional information about SGSH?

You and your healthcare professional may find the following resources about SGSH helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the SGSH gene or gene products?

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

See How are genetic conditions and genes named? ( in the Handbook.

What glossary definitions help with understanding SGSH?

breakdown ; central nervous system ; DNA ; enzyme ; gene ; heparan sulfate ; molecule ; nervous system ; precursor ; sulfate

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • Meyer A, Kossow K, Gal A, Steglich C, Mühlhausen 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. (
  • 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. (
  • NCBI Gene (
  • 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. Review. (


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? ( in the Handbook.

Reviewed: August 2010
Published: February 1, 2016