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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 GUSB gene?

The official name of this gene is “glucuronidase, beta.”

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

What is the normal function of the GUSB gene?

The GUSB gene provides instructions for producing an enzyme called beta-glucuronidase (β-glucuronidase). This enzyme is located in lysosomes, compartments within cells that digest and recycle different types of molecules. β-glucuronidase is involved in the 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. β-glucuronidase is involved in the break down of three types of GAGs: dermatan sulfate, heparan sulfate, and chondroitin sulfate. This enzyme removes a sugar called glucuronic acid when it is at the end of the GAG chain.

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

mucopolysaccharidosis type VII - caused by mutations in the GUSB gene

At least 55 mutations in the GUSB gene have been found to cause mucopolysaccharidosis type VII (MPS VII). Most of these mutations change single DNA building blocks (nucleotides) in the gene. All of the mutations that cause MPS VII reduce or eliminate the function of β-glucuronidase.

The shortage (deficiency) of β-glucuronidase leads to the accumulation of dermatan sulfate, heparan sulfate, and chondroitin sulfate within lysosomes in virtually all tissues and organs. The buildup of these GAGs increases the size of the lysosomes, which is why many tissues and organs are enlarged in MPS VII. Researchers believe that the accumulated GAGs may also interfere with the functions of other proteins inside the lysosomes and disrupt many normal functions of cells.

Where is the GUSB gene located?

Cytogenetic Location: 7q21.11

Molecular Location on chromosome 7: base pairs 65,960,684 to 65,982,314

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

The GUSB gene is located on the long (q) arm of chromosome 7 at position 21.11.

The GUSB gene is located on the long (q) arm of chromosome 7 at position 21.11.

More precisely, the GUSB gene is located from base pair 65,960,684 to base pair 65,982,314 on chromosome 7.

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

Where can I find additional information about GUSB?

You and your healthcare professional may find the following resources about GUSB 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 GUSB gene or gene products?

  • beta-D-glucuronidase
  • beta-G1
  • beta-glucuronidase
  • beta-glucuronidase precursor
  • BG
  • FLJ39445
  • MPS7

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

What glossary definitions help with understanding GUSB?

breakdown ; deficiency ; DNA ; enzyme ; gene ; heparan sulfate ; molecule ; precursor ; sulfate

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


  • NCBI Gene (
  • Storch S, Wittenstein B, Islam R, Ullrich K, Sly WS, Braulke T. Mutational analysis in longest known survivor of mucopolysaccharidosis type VII. Hum Genet. 2003 Feb;112(2):190-4. Epub 2002 Nov 5. (
  • Tomatsu S, Montaño AM, Dung VC, Grubb JH, Sly WS. Mutations and polymorphisms in GUSB gene in mucopolysaccharidosis VII (Sly Syndrome). Hum Mutat. 2009 Apr;30(4):511-9. doi: 10.1002/humu.20828. Review. (
  • Vervoort R, Islam MR, Sly WS, Zabot MT, Kleijer WJ, Chabas A, Fensom A, Young EP, Liebaers I, Lissens W. Molecular analysis of patients with beta-glucuronidase deficiency presenting as hydrops fetalis or as early mucopolysaccharidosis VII. Am J Hum Genet. 1996 Mar;58(3):457-71. (


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 8, 2016