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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed June 2008

What is the official name of the APTX gene?

The official name of this gene is “aprataxin.”

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

What is the normal function of the APTX gene?

The APTX gene provides instructions for making a protein called aprataxin that is involved in DNA repair. Aprataxin is produced in various tissues, including the brain, spinal cord, and muscles. Different regions of the aprataxin protein aid in its DNA repair function by allowing the protein to interact with other DNA repair proteins and to attach (bind) to DNA molecules.

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

ataxia with oculomotor apraxia - caused by mutations in the APTX gene

At least 18 mutations in the APTX gene have been found to cause ataxia with oculomotor apraxia type 1. Most of the mutations change one of the protein building blocks (amino acids) used to make aprataxin. Mutations in the APTX gene result in an unstable aprataxin protein that quickly gets broken down in the cell. A lack of functional aprataxin can lead to an accumulation of DNA damage in cells, particularly affecting brain cells in the part of the brain involved in coordinating movements (the cerebellum). This accumulation can lead to cell death in the cerebellum, causing the characteristic movement problems of ataxia with oculomotor apraxia type 1.

Where is the APTX gene located?

Cytogenetic Location: 9p13.3

Molecular Location on chromosome 9: base pairs 32,972,605 to 33,025,137

The APTX gene is located on the short (p) arm of chromosome 9 at position 13.3.

The APTX gene is located on the short (p) arm of chromosome 9 at position 13.3.

More precisely, the APTX gene is located from base pair 32,972,605 to base pair 33,025,137 on chromosome 9.

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

Where can I find additional information about APTX?

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

  • AOA
  • AOA1
  • ataxia 1, early onset with hypoalbuminemia
  • AXA1
  • EAOH

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

What glossary definitions help with understanding APTX?

acids ; apraxia ; ataxia ; cell ; cerebellum ; DNA ; DNA damage ; DNA repair ; gene ; protein

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


  • Hirano M, Asai H, Kiriyama T, Furiya Y, Iwamoto T, Nishiwaki T, Yamamoto A, Mori T, Ueno S. Short half-lives of ataxia-associated aprataxin proteins in neuronal cells. Neurosci Lett. 2007 May 29;419(2):184-7. Epub 2007 Apr 25. (
  • Le Ber I, Moreira MC, Rivaud-Péchoux S, Chamayou C, Ochsner F, Kuntzer T, Tardieu M, Saïd G, Habert MO, Demarquay G, Tannier C, Beis JM, Brice A, Koenig M, Dürr A. Cerebellar ataxia with oculomotor apraxia type 1: clinical and genetic studies. Brain. 2003 Dec;126(Pt 12):2761-72. Epub 2003 Sep 23. (
  • NCBI Gene (
  • Rass U, Ahel I, West SC. Actions of aprataxin in multiple DNA repair pathways. J Biol Chem. 2007 Mar 30;282(13):9469-74. Epub 2007 Feb 2. (
  • Takahashi T, Tada M, Igarashi S, Koyama A, Date H, Yokoseki A, Shiga A, Yoshida Y, Tsuji S, Nishizawa M, Onodera O. Aprataxin, causative gene product for EAOH/AOA1, repairs DNA single-strand breaks with damaged 3'-phosphate and 3'-phosphoglycolate ends. Nucleic Acids Res. 2007;35(11):3797-809. Epub 2007 May 22. (


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: June 2008
Published: March 23, 2015