Skip Navigation
Genetics Home Reference: your guide to understanding genetic conditions About   Site Map   Contact Us
Home A service of the U.S. National Library of Medicine®
Printer-friendly version


Reviewed July 2010

What is the official name of the GALNS gene?

The official name of this gene is “galactosamine (N-acetyl)-6-sulfatase.”

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

Read more about gene names and symbols on the About page.

What is the normal function of the GALNS gene?

The GALNS gene provides instructions for producing an enzyme called N-acetylgalactosamine 6-sulfatase. This enzyme is located in lysosomes, which are compartments within cells that break down and recycle different types of molecules. N-acetylgalactosamine 6-sulfatase is involved in the breakdown of large sugar molecules called glycosaminoglycans (GAGs) or mucopolysaccharides. Specifically, this enzyme removes a chemical group known as a sulfate from a GAG called keratan sulfate. Keratan sulfate is particularly abundant in cartilage and the clear covering of the eye (cornea).

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

mucopolysaccharidosis type IV - caused by mutations in the GALNS gene

More than 148 mutations in the GALNS gene have been found to cause mucopolysaccharidosis type IV (MPS IV). Most of these mutations change single DNA building blocks (nucleotides) in the gene. All of the mutations that cause MPS IV reduce or eliminate the function of N-acetylgalactosamine 6-sulfatase.

The lack of N-acetylgalactosamine 6-sulfatase activity leads to the accumulation of keratan sulfate within lysosomes. Because keratan sulfate is predominantly found in cartilage and the cornea, the buildup of this substance causes skeletal abnormalities and cloudy corneas. Researchers believe that a buildup of GAGs may also cause the features of MPS IV by interfering with the functions of other proteins inside lysosomes and disrupting the movement of molecules inside the cell.

Where is the GALNS gene located?

Cytogenetic Location: 16q24.3

Molecular Location on chromosome 16: base pairs 88,813,734 to 88,856,966

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBIThis link leads to a site outside Genetics Home Reference.)

The GALNS gene is located on the long (q) arm of chromosome 16 at position 24.3.

The GALNS gene is located on the long (q) arm of chromosome 16 at position 24.3.

More precisely, the GALNS gene is located from base pair 88,813,734 to base pair 88,856,966 on chromosome 16.

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

Where can I find additional information about GALNS?

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

  • chondroitinase
  • chondroitinsulfatase
  • FLJ17434
  • FLJ42844
  • FLJ98217
  • galactosamine (N-acetyl)-6-sulfate sulfatase
  • galactose-6-sulfate sulfatase
  • galNAc6S sulfatase
  • GAS
  • MPS4A
  • N-acetylgalactosamine-6-sulfatase
  • N-acetylgalactosamine-6-sulfatase precursor
  • N-acetylgalactosamine-6-sulfate sulfatase

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding GALNS?

breakdown ; cartilage ; cell ; cornea ; DNA ; enzyme ; galactose ; gene ; precursor ; sulfate

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

See also Understanding Medical Terminology.

References (5 links)


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: July 2010
Published: February 1, 2016