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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 NAGLU gene?

The official name of this gene is “N-acetylglucosaminidase, alpha.”

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

What is the normal function of the NAGLU gene?

The NAGLU gene provides instructions for producing an enzyme called alpha-N-acetylglucosaminidase. This enzyme is located in lysosomes, compartments within cells that digest and recycle different types of molecules. Alpha-N-acetylglucosaminidase 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. Alpha-N-acetylglucosaminidase removes a sugar called N-acetylglucosamine when it is at the end of the GAG chain.

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

mucopolysaccharidosis type III - caused by mutations in the NAGLU gene

At least 118 mutations in the NAGLU gene have been found to cause mucopolysaccharidosis type IIIB (MPS IIIB). Most of these mutations change single DNA building blocks (nucleotides) in the gene. All of the mutations that cause MPS IIIB reduce or eliminate the function of alpha-N-acetylglucosaminidase.

The lack of alpha-N-acetylglucosaminidase 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 IIIB.

Where is the NAGLU gene located?

Cytogenetic Location: 17q21

Molecular Location on chromosome 17: base pairs 42,535,933 to 42,544,449

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

The NAGLU gene is located on the long (q) arm of chromosome 17 at position 21.

The NAGLU gene is located on the long (q) arm of chromosome 17 at position 21.

More precisely, the NAGLU gene is located from base pair 42,535,933 to base pair 42,544,449 on chromosome 17.

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

Where can I find additional information about NAGLU?

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

  • alpha-N-acetylglucosaminidase
  • alpha-N-acetylglucosaminidase precursor
  • N-acetyl-alpha-glucosaminidase
  • N-acetylglucosaminidase, alpha-
  • NAG

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

What glossary definitions help with understanding NAGLU?

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.


  • Beesley CE, Jackson M, Young EP, Vellodi A, Winchester BG. Molecular defects in Sanfilippo syndrome type B (mucopolysaccharidosis IIIB). J Inherit Metab Dis. 2005;28(5):759-67. (
  • Ficko-Blean E, Stubbs KA, Nemirovsky O, Vocadlo DJ, Boraston AB. Structural and mechanistic insight into the basis of mucopolysaccharidosis IIIB. Proc Natl Acad Sci U S A. 2008 May 6;105(18):6560-5. doi: 10.1073/pnas.0711491105. Epub 2008 Apr 28. (
  • NCBI Gene (
  • Ohmi K, Kudo LC, Ryazantsev S, Zhao HZ, Karsten SL, Neufeld EF. Sanfilippo syndrome type B, a lysosomal storage disease, is also a tauopathy. Proc Natl Acad Sci U S A. 2009 May 19;106(20):8332-7. doi: 10.1073/pnas.0903223106. Epub 2009 May 5. (
  • 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