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Reviewed January 2008

What is the official name of the ASPA gene?

The official name of this gene is “aspartoacylase.”

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

The ASPA gene provides instructions for making an enzyme called aspartoacylase. In the brain, this enzyme breaks down a compound called N-acetyl-L-aspartic acid (NAA) into aspartic acid (an amino acid that is a building block of many proteins) and another molecule called acetic acid.

The cycle of production and breakdown of NAA appears to be critical for maintaining the brain's white matter, which consists of nerve fibers covered by myelin. Myelin is the fatty substance that insulates and protects nerves. Although the precise function of NAA is unknown, it is probably essential for making certain fats (lipids) that are used to produce myelin. Researchers believe that NAA may also play a role in transporting molecules of water out of nerve cells.

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

Canavan disease - caused by mutations in the ASPA gene

More than 55 mutations in the ASPA gene are known to cause Canavan disease. Two specific mutations cause most cases of the disease in people of Ashkenazi (eastern and central European) Jewish descent. One of these mutations changes a single protein building block (amino acid) in aspartoacylase. Specifically, this mutation replaces the amino acid glutamic acid with the amino acid alanine at position 285 of the enzyme (written as Glu285Ala or E285A). The other common mutation, which is written as Tyr231Ter or Y231X, prematurely stops protein production and leads to an abnormally small, nonfunctional version of the enzyme.

A different mutation is most common in people who are not of Ashkenazi Jewish descent. This mutation substitutes the amino acid glutamic acid for the amino acid alanine at position 305 of aspartoacylase (written as Ala305Glu or A305E).

Mutations in the ASPA gene reduce or eliminate the activity of aspartoacylase, which prevents the normal breakdown of NAA in the brain. Recent studies suggest that if NAA is not broken down properly, the resulting chemical imbalance may interfere with the formation of myelin as the nervous system develops. A buildup of NAA also leads to the progressive destruction of existing myelin around nerve cells. Nerve fibers without this protective covering malfunction and die, damaging the brain and causing the serious signs and symptoms of Canavan disease.

Where is the ASPA gene located?

Cytogenetic Location: 17p13.3

Molecular Location on chromosome 17: base pairs 3,474,109 to 3,499,405

The ASPA gene is located on the short (p) arm of chromosome 17 at position 13.3.

The ASPA gene is located on the short (p) arm of chromosome 17 at position 13.3.

More precisely, the ASPA gene is located from base pair 3,474,109 to base pair 3,499,405 on chromosome 17.

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

Where can I find additional information about ASPA?

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

  • ACY2
  • aminoacylase 2
  • aminoacylase II
  • ASP
  • aspartoacylase (aminoacylase 2, Canavan disease)
  • aspartoacylase (Canavan disease)
  • N-acyl-L-aspartate amidohydrolase

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 ASPA?

alanine ; amino acid ; Ashkenazi Jewish ; Asp ; aspartic acid ; breakdown ; compound ; enzyme ; gene ; glutamic acid ; L-aspartic acid ; molecule ; mutation ; nervous system ; protein ; white matter

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

See also Understanding Medical Terminology.

References (11 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: January 2008
Published: March 23, 2015