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Reviewed July 2014

What is the official name of the ST3GAL5 gene?

The official name of this gene is “ST3 beta-galactoside alpha-2,3-sialyltransferase 5.”

ST3GAL5 is the gene's official symbol. The ST3GAL5 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 ST3GAL5 gene?

The ST3GAL5 gene provides instructions for making an enzyme called GM3 synthase. This enzyme carries out a chemical reaction that is the first step in the production of certain fatty molecules (lipids) called gangliosides. Specifically, GM3 synthase converts a molecule called lactosylceramide to a simple ganglioside called GM3. Further reactions use GM3 to create more complex gangliosides.

Gangliosides are present on the surface of cells and tissues throughout the body, and they are particularly abundant in the nervous system. Although their exact functions are unclear, studies suggest that these molecules help regulate chemical signaling pathways that influence cell growth and division (proliferation), cell movement (motility), the attachment of cells to one another (adhesion), and cell survival. Gangliosides appear to be important for normal brain development and function.

Does the ST3GAL5 gene share characteristics with other genes?

The ST3GAL5 gene belongs to a family of genes called ST3G (sialyltransferases).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? in the Handbook.

How are changes in the ST3GAL5 gene related to health conditions?

GM3 synthase deficiency - caused by mutations in the ST3GAL5 gene

At least one mutation in the ST3GAL5 gene has been found to cause GM3 synthase deficiency, a condition characterized by recurrent seizures (epilepsy) and problems with brain development. The known mutation replaces a single protein building block (amino acid), arginine, with a signal to stop protein production prematurely. The mutation is written as Arg288Ter or R288X, although in older scientific articles it is sometimes written as Arg232Ter or R232X. The mutation prevents the production of any functional GM3 synthase. Without this enzyme, cells cannot produce GM3 or other gangliosides normally. It is unclear how a loss of this enzyme leads to the signs and symptoms of GM3 synthase deficiency. Researchers are working to determine whether it is the lack of gangliosides or a buildup of compounds used to make gangliosides, or both, that underlies the seizures and other problems with brain development that occur in this condition.

Where is the ST3GAL5 gene located?

Cytogenetic Location: 2p11.2

Molecular Location on chromosome 2: base pairs 85,839,147 to 85,889,034

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

The ST3GAL5 gene is located on the short (p) arm of chromosome 2 at position 11.2.

The ST3GAL5 gene is located on the short (p) arm of chromosome 2 at position 11.2.

More precisely, the ST3GAL5 gene is located from base pair 85,839,147 to base pair 85,889,034 on chromosome 2.

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

Where can I find additional information about ST3GAL5?

You and your healthcare professional may find the following resources about ST3GAL5 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 ST3GAL5 gene or gene products?

  • alpha 2,3-sialyltransferase V
  • CMP-NeuAc:lactosylceramide alpha-2,3-sialyltransferase
  • ganglioside GM3 synthase
  • GM3 synthase
  • lactosylceramide alpha-2,3-sialyltransferase
  • lactosylceramide alpha-2,3-sialyltransferase isoform 1
  • lactosylceramide alpha-2,3-sialyltransferase isoform 2
  • SATI
  • sialyltransferase 9 (CMP-NeuAc:lactosylceramide alpha-2,3-sialyltransferase; GM3 synthase)
  • SIAT9
  • ST3GalV
  • ST3Gal V

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 ST3GAL5?

amino acid ; arginine ; cell ; deficiency ; enzyme ; epilepsy ; gene ; molecule ; mutation ; nervous system ; proliferation ; protein ; sialic acid

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

See also Understanding Medical Terminology.

References (8 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 2014
Published: February 1, 2016