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


Reviewed April 2015

What is the official name of the SETX gene?

The official name of this gene is “senataxin.”

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

What is the normal function of the SETX gene?

The SETX gene provides instructions for making a protein called senataxin. Senataxin is produced in a wide range of tissues, including the brain, spinal cord, and muscles. Based on the structure of senataxin, researchers believe that it is one of a class of proteins called helicases that are involved in DNA repair and the production of RNA, a chemical cousin of DNA. Helicases attach to particular regions of DNA and temporarily unwind the two spiral strands of a DNA molecule. By unwinding the strands near sites of DNA damage, helicases allow other proteins to reach damaged areas and fix them. Senataxin is thought to aid in DNA repair through this helicase mechanism. This unwinding mechanism may also be involved in using the instructions encoded by RNA to create different versions of certain proteins (RNA processing).

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

amyotrophic lateral sclerosis - caused by mutations in the SETX gene

Researchers have identified at least 20 SETX gene mutations that cause amyotrophic lateral sclerosis (ALS), a condition characterized by progressive movement problems and muscle wasting. Mutations in the SETX gene cause the juvenile form of ALS, which usually develops in a person's teens or twenties. These mutations change single protein building blocks (amino acids) in the senataxin protein. This type of mutation may alter the 3-dimensional shape of senataxin and disrupt its normal function. It is unclear how mutations in the SETX gene cause juvenile ALS.

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

At least 115 mutations in the SETX gene have been found to cause ataxia with oculomotor apraxia type 2. This condition is characterized by difficulty coordinating movements (ataxia) and problems with side-to-side movements of the eyes (oculomotor apraxia). Most mutations replace single amino acids in senataxin. The mutations associated with ataxia with oculomotor apraxia type 2 are thought to disrupt the helicase function of senataxin. A lack of functional senataxin disrupts DNA repair and 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 2.

Where is the SETX gene located?

Cytogenetic Location: 9q34.13

Molecular Location on chromosome 9: base pairs 132,261,440 to 132,356,726

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

The SETX gene is located on the long (q) arm of chromosome 9 at position 34.13.

The SETX gene is located on the long (q) arm of chromosome 9 at position 34.13.

More precisely, the SETX gene is located from base pair 132,261,440 to base pair 132,356,726 on chromosome 9.

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

Where can I find additional information about SETX?

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

  • ALS4
  • AOA2
  • KIAA0625
  • SCAR1

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

What glossary definitions help with understanding SETX?

acids ; apraxia ; ataxia ; cell ; cerebellum ; class ; DNA ; DNA damage ; DNA repair ; gene ; helicase ; juvenile ; molecule ; mutation ; protein ; RNA ; sclerosis ; wasting

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


  • Becherel OJ, Yeo AJ, Stellati A, Heng EY, Luff J, Suraweera AM, Woods R, Fleming J, Carrie D, McKinney K, Xu X, Deng C, Lavin MF. Senataxin plays an essential role with DNA damage response proteins in meiotic recombination and gene silencing. PLoS Genet. 2013 Apr;9(4):e1003435. doi: 10.1371/journal.pgen.1003435. Epub 2013 Apr 11. (
  • Blair IP, Bennett CL, Abel A, Rabin BA, Griffin JW, Fischbeck KH, Cornblath DR, Chance PF. A gene for autosomal dominant juvenile amyotrophic lateral sclerosis (ALS4) localizes to a 500-kb interval on chromosome 9q34. Neurogenetics. 2000 Sep;3(1):1-6. (
  • Chance PF, Rabin BA, Ryan SG, Ding Y, Scavina M, Crain B, Griffin JW, Cornblath DR. Linkage of the gene for an autosomal dominant form of juvenile amyotrophic lateral sclerosis to chromosome 9q34. Am J Hum Genet. 1998 Mar;62(3):633-40. (
  • Chen YZ, Bennett CL, Huynh HM, Blair IP, Puls I, Irobi J, Dierick I, Abel A, Kennerson ML, Rabin BA, Nicholson GA, Auer-Grumbach M, Wagner K, De Jonghe P, Griffin JW, Fischbeck KH, Timmerman V, Cornblath DR, Chance PF. DNA/RNA helicase gene mutations in a form of juvenile amyotrophic lateral sclerosis (ALS4). Am J Hum Genet. 2004 Jun;74(6):1128-35. Epub 2004 Apr 21. (
  • Ferraiuolo L, Kirby J, Grierson AJ, Sendtner M, Shaw PJ. Molecular pathways of motor neuron injury in amyotrophic lateral sclerosis. Nat Rev Neurol. 2011 Nov;7(11):616-30. doi: 10.1038/nrneurol.2011.152. Review. (
  • Fogel BL, Perlman S. Novel mutations in the senataxin DNA/RNA helicase domain in ataxia with oculomotor apraxia 2. Neurology. 2006 Dec 12;67(11):2083-4. (
  • Kunst CB. Complex genetics of amyotrophic lateral sclerosis. Am J Hum Genet. 2004 Dec;75(6):933-47. Epub 2004 Oct 11. Review. (
  • Le Ber I, Bouslam N, Rivaud-Péchoux S, Guimarães J, Benomar A, Chamayou C, Goizet C, Moreira MC, Klur S, Yahyaoui M, Agid Y, Koenig M, Stevanin G, Brice A, Dürr A. Frequency and phenotypic spectrum of ataxia with oculomotor apraxia 2: a clinical and genetic study in 18 patients. Brain. 2004 Apr;127(Pt 4):759-67. Epub 2004 Jan 21. (
  • Moreira MC, Klur S, Watanabe M, Németh AH, Le Ber I, Moniz JC, Tranchant C, Aubourg P, Tazir M, Schöls L, Pandolfo M, Schulz JB, Pouget J, Calvas P, Shizuka-Ikeda M, Shoji M, Tanaka M, Izatt L, Shaw CE, M'Zahem A, Dunne E, Bomont P, Benhassine T, Bouslam N, Stevanin G, Brice A, Guimarães J, Mendonça P, Barbot C, Coutinho P, Sequeiros J, Dürr A, Warter JM, Koenig M. Senataxin, the ortholog of a yeast RNA helicase, is mutant in ataxia-ocular apraxia 2. Nat Genet. 2004 Mar;36(3):225-7. Epub 2004 Feb 8. (
  • Nanetti L, Cavalieri S, Pensato V, Erbetta A, Pareyson D, Panzeri M, Zorzi G, Antozzi C, Moroni I, Gellera C, Brusco A, Mariotti C. SETX mutations are a frequent genetic cause of juvenile and adult onset cerebellar ataxia with neuropathy and elevated serum alpha-fetoprotein. Orphanet J Rare Dis. 2013 Aug 14;8:123. doi: 10.1186/1750-1172-8-123. (
  • NCBI Gene (
  • Suraweera A, Becherel OJ, Chen P, Rundle N, Woods R, Nakamura J, Gatei M, Criscuolo C, Filla A, Chessa L, Fusser M, Epe B, Gueven N, Lavin MF. Senataxin, defective in ataxia oculomotor apraxia type 2, is involved in the defense against oxidative DNA damage. J Cell Biol. 2007 Jun 18;177(6):969-79. Epub 2007 Jun 11. (


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: April 2015
Published: February 8, 2016