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


Reviewed July 2010

What is the official name of the TREX1 gene?

The official name of this gene is “three prime repair exonuclease 1.”

TREX1 is the gene's official symbol. The TREX1 gene is also known by other names, listed below.

What is the normal function of the TREX1 gene?

The TREX1 gene provides instructions for making the 3-prime repair exonuclease 1 enzyme. This enzyme is a DNA exonuclease, which means it trims molecules of DNA by removing DNA building blocks (nucleotides) from the ends of the molecules. In this way, it breaks down unneeded DNA molecules or fragments that may be generated during copying (replication) of cells' genetic material in preparation for cell division, DNA repair, cell death, and other processes.

How are changes in the TREX1 gene related to health conditions?

Aicardi-Goutieres syndrome - caused by mutations in the TREX1 gene

At least 16 mutations in the TREX1 gene have been identified in people with Aicardi-Goutieres syndrome. Most of these mutations are believed to prevent the production of the 3-prime repair exonuclease 1 enzyme. Researchers suggest that the absence of this enzyme may result in an accumulation of unneeded DNA and RNA in cells. These DNA and RNA molecules may be mistaken by cells for those of viral invaders, triggering immune system reactions that result in severe brain dysfunction (encephalopathy), skin lesions, and other signs and symptoms of Aicardi-Goutieres syndrome.

other disorders - caused by mutations in the TREX1 gene

Mutations in the TREX1 gene have also been identified in people with other disorders involving the immune system. These disorders include a chronic inflammatory disease called systemic lupus erythematosus (SLE), including a rare form of SLE called chilblain lupus that mainly affects the skin.

TREX1 gene mutations have also been found in people with a disorder called autosomal dominant retinal vasculopathy with cerebral leukodystrophy, which affects the brain and the blood vessels in the specialized light-sensitive tissue that lines the back of the eye (the retina).

As in Aicardi-Goutieres syndrome, absence or impaired function of the 3-prime repair exonuclease 1 enzyme may cause immune system dysfunction that damages the brain, skin, blood vessels, and other parts of the body in these conditions. It is not clear why mutations in the same gene cause several different disorders.

Where is the TREX1 gene located?

Cytogenetic Location: 3p21.31

Molecular Location on chromosome 3: base pairs 48,465,520 to 48,467,645

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

The TREX1 gene is located on the short (p) arm of chromosome 3 at position 21.31.

The TREX1 gene is located on the short (p) arm of chromosome 3 at position 21.31.

More precisely, the TREX1 gene is located from base pair 48,465,520 to base pair 48,467,645 on chromosome 3.

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

Where can I find additional information about TREX1?

You and your healthcare professional may find the following resources about TREX1 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 TREX1 gene or gene products?

  • 3'-5' exonuclease TREX1
  • 3' repair exonuclease 1
  • AGS1
  • CRV
  • deoxyribonuclease III, dnaQ/mutD-like
  • DKFZp434J0310
  • DNase III
  • DRN3
  • three prime repair exonuclease 1 isoform a
  • three prime repair exonuclease 1 isoform b

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

What glossary definitions help with understanding TREX1?

autosomal ; autosomal dominant ; cell ; cell division ; chronic ; DNA ; DNA repair ; encephalopathy ; enzyme ; gene ; immune system ; leukodystrophy ; retina ; RNA ; syndrome ; tissue

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


  • Crow YJ, Rehwinkel J. Aicardi-Goutieres syndrome and related phenotypes: linking nucleic acid metabolism with autoimmunity. Hum Mol Genet. 2009 Oct 15;18(R2):R130-6. doi: 10.1093/hmg/ddp293. Review. (
  • Kavanagh D, Spitzer D, Kothari PH, Shaikh A, Liszewski MK, Richards A, Atkinson JP. New roles for the major human 3'-5' exonuclease TREX1 in human disease. Cell Cycle. 2008 Jun 15;7(12):1718-25. Epub 2008 Jun 16. Review. (
  • Lehtinen DA, Harvey S, Mulcahy MJ, Hollis T, Perrino FW. The TREX1 double-stranded DNA degradation activity is defective in dominant mutations associated with autoimmune disease. J Biol Chem. 2008 Nov 14;283(46):31649-56. doi: 10.1074/jbc.M806155200. Epub 2008 Sep 18. (
  • Lindahl T, Barnes DE, Yang YG, Robins P. Biochemical properties of mammalian TREX1 and its association with DNA replication and inherited inflammatory disease. Biochem Soc Trans. 2009 Jun;37(Pt 3):535-8. doi: 10.1042/BST0370535. (
  • NCBI Gene (
  • Rice G, Newman WG, Dean J, Patrick T, Parmar R, Flintoff K, Robins P, Harvey S, Hollis T, O'Hara A, Herrick AL, Bowden AP, Perrino FW, Lindahl T, Barnes DE, Crow YJ. Heterozygous mutations in TREX1 cause familial chilblain lupus and dominant Aicardi-Goutieres syndrome. Am J Hum Genet. 2007 Apr;80(4):811-5. Epub 2007 Feb 19. (
  • Rice G, Patrick T, Parmar R, Taylor CF, Aeby A, Aicardi J, Artuch R, Montalto SA, Bacino CA, Barroso B, Baxter P, Benko WS, Bergmann C, Bertini E, Biancheri R, Blair EM, Blau N, Bonthron DT, Briggs T, Brueton LA, Brunner HG, Burke CJ, Carr IM, Carvalho DR, Chandler KE, Christen HJ, Corry PC, Cowan FM, Cox H, D'Arrigo S, Dean J, De Laet C, De Praeter C, Dery C, Ferrie CD, Flintoff K, Frints SG, Garcia-Cazorla A, Gener B, Goizet C, Goutieres F, Green AJ, Guet A, Hamel BC, Hayward BE, Heiberg A, Hennekam RC, Husson M, Jackson AP, Jayatunga R, Jiang YH, Kant SG, Kao A, King MD, Kingston HM, Klepper J, van der Knaap MS, Kornberg AJ, Kotzot D, Kratzer W, Lacombe D, Lagae L, Landrieu PG, Lanzi G, Leitch A, Lim MJ, Livingston JH, Lourenco CM, Lyall EG, Lynch SA, Lyons MJ, Marom D, McClure JP, McWilliam R, Melancon SB, Mewasingh LD, Moutard ML, Nischal KK, Ostergaard JR, Prendiville J, Rasmussen M, Rogers RC, Roland D, Rosser EM, Rostasy K, Roubertie A, Sanchis A, Schiffmann R, Scholl-Burgi S, Seal S, Shalev SA, Corcoles CS, Sinha GP, Soler D, Spiegel R, Stephenson JB, Tacke U, Tan TY, Till M, Tolmie JL, Tomlin P, Vagnarelli F, Valente EM, Van Coster RN, Van der Aa N, Vanderver A, Vles JS, Voit T, Wassmer E, Weschke B, Whiteford ML, Willemsen MA, Zankl A, Zuberi SM, Orcesi S, Fazzi E, Lebon P, Crow YJ. Clinical and molecular phenotype of Aicardi-Goutieres syndrome. Am J Hum Genet. 2007 Oct;81(4):713-25. Epub 2007 Sep 4. (
  • Rigby RE, Leitch A, Jackson AP. Nucleic acid-mediated inflammatory diseases. Bioessays. 2008 Sep;30(9):833-42. doi: 10.1002/bies.20808. Review. (


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 8, 2016