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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 2014

What is the official name of the FAS gene?

The official name of this gene is “Fas cell surface death receptor.”

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

What is the normal function of the FAS gene?

The FAS gene provides instructions for making a protein that is involved in signaling. Three FAS proteins group together to form a structure called a trimer, which then interacts with other molecules to perform its signaling function. This signaling initiates a process called a caspase cascade. The caspase cascade is a series of steps that results in the self-destruction of cells (apoptosis) when they are not needed.

Does the FAS gene share characteristics with other genes?

The FAS gene belongs to a family of genes called CD (CD molecules). It also belongs to a family of genes called TNFRSF (tumor necrosis factor receptor superfamily).

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 FAS gene related to health conditions?

autoimmune lymphoproliferative syndrome - caused by mutations in the FAS gene

More than 100 mutations in the FAS gene have been identified in people with a disorder of the immune system called autoimmune lymphoproliferative syndrome (ALPS). ALPS is characterized by the production of an abnormally large number of immune system cells (lymphocytes), resulting in enlargement of the lymph nodes (lymphadenopathy), the liver (hepatomegaly), and the spleen (splenomegaly). Autoimmune disorders, in which the immune system malfunctions and attacks the body's own tissues and organs, are also common in ALPS. People with ALPS have an increased risk of developing cancer of the immune system cells (lymphoma) and may also be at increased risk of developing other cancers.

When the immune system is activated to fight an infection, large numbers of lymphocytes are produced. Normally, these lymphocytes undergo apoptosis when they are no longer required. FAS gene mutations result in an abnormal trimer that interferes with the initiation of apoptosis. Excess lymphocytes accumulate in the body's tissues and organs and often begin attacking them, leading to autoimmune disorders. Interference with apoptosis allows cells to multiply without control, leading to the lymphomas and other cancers that occur in people with this disorder.

cancers - increased risk from variations of the FAS gene

Studies have associated certain FAS gene variations with increased risk of developing cancer, including cancers of the lung, breast, and esophagus. Researchers believe that these variations may affect the signaling that initiates apoptosis, increasing the risk that cells will multiply out of control and result in cancer.

Where is the FAS gene located?

Cytogenetic Location: 10q24.1

Molecular Location on chromosome 10: base pairs 88,969,801 to 89,017,059

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

The FAS gene is located on the long (q) arm of chromosome 10 at position 24.1.

The FAS gene is located on the long (q) arm of chromosome 10 at position 24.1.

More precisely, the FAS gene is located from base pair 88,969,801 to base pair 89,017,059 on chromosome 10.

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

Where can I find additional information about FAS?

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

  • APO-1
  • apo-1 antigen
  • APO-1 cell surface antigen
  • apoptosis antigen 1
  • apoptosis-mediating surface antigen FAS
  • APT1
  • CD95
  • CD95 antigen
  • FAS1
  • Fas AMA
  • Fas antigen
  • FASLG receptor
  • Fas (TNF receptor superfamily, member 6)
  • tumor necrosis factor receptor superfamily member 6

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

What glossary definitions help with understanding FAS?

apoptosis ; autoimmune ; cancer ; caspase ; cell ; esophagus ; FAS ; gene ; immune system ; infection ; lymph ; lymphoma ; mediating ; necrosis ; protein ; receptor ; splenomegaly ; syndrome ; tumor

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


  • Cao Y, Miao XP, Huang MY, Deng L, Lin DX, Zeng YX, Shao JY. Polymorphisms of death pathway genes FAS and FASL and risk of nasopharyngeal carcinoma. Mol Carcinog. 2010 Nov;49(11):944-50. doi: 10.1002/mc.20676. (
  • Dowdell KC, Niemela JE, Price S, Davis J, Hornung RL, Oliveira JB, Puck JM, Jaffe ES, Pittaluga S, Cohen JI, Fleisher TA, Rao VK. Somatic FAS mutations are common in patients with genetically undefined autoimmune lymphoproliferative syndrome. Blood. 2010 Jun 24;115(25):5164-9. doi: 10.1182/blood-2010-01-263145. Epub 2010 Apr 1. (
  • Fleisher TA, Straus SE, Bleesing JJ. A genetic disorder of lymphocyte apoptosis involving the fas pathway: the autoimmune lymphoproliferative syndrome. Curr Allergy Asthma Rep. 2001 Nov;1(6):534-40. Review. (
  • Fleisher TA. The autoimmune lymphoproliferative syndrome: an experiment of nature involving lymphocyte apoptosis. Immunol Res. 2008;40(1):87-92. doi: 10.1007/s12026-007-8001-1. (
  • NCBI Gene (
  • Poppema S, Maggio E, van den Berg A. Development of lymphoma in Autoimmune Lymphoproliferative Syndrome (ALPS) and its relationship to Fas gene mutations. Leuk Lymphoma. 2004 Mar;45(3):423-31. Review. (
  • Randhawa SR, Chahine BG, Lowery-Nordberg M, Cotelingam JD, Casillas AM. Underexpression and overexpression of Fas and Fas ligand: a double-edged sword. Ann Allergy Asthma Immunol. 2010 Apr;104(4):286-92. doi: 10.1016/j.anai.2010.01.021. Review. (
  • Rieux-Laucat F. Inherited and acquired death receptor defects in human Autoimmune Lymphoproliferative Syndrome. Curr Dir Autoimmun. 2006;9:18-36. Review. (
  • Sun T, Miao X, Zhang X, Tan W, Xiong P, Lin D. Polymorphisms of death pathway genes FAS and FASL in esophageal squamous-cell carcinoma. J Natl Cancer Inst. 2004 Jul 7;96(13):1030-6. (
  • Teachey DT, Seif AE, Grupp SA. Advances in the management and understanding of autoimmune lymphoproliferative syndrome (ALPS). Br J Haematol. 2010 Jan;148(2):205-16. doi: 10.1111/j.1365-2141.2009.07991.x. Epub 2009 Nov 23. Review. (
  • Turbyville JC, Rao VK. The autoimmune lymphoproliferative syndrome: A rare disorder providing clues about normal tolerance. Autoimmun Rev. 2010 May;9(7):488-93. doi: 10.1016/j.autrev.2010.02.007. Epub 2010 Feb 17. Review. (
  • Worth A, Thrasher AJ, Gaspar HB. Autoimmune lymphoproliferative syndrome: molecular basis of disease and clinical phenotype. Br J Haematol. 2006 Apr;133(2):124-40. Review. (
  • Zhang B, Sun T, Xue L, Han X, Zhang B, Lu N, Shi Y, Tan W, Zhou Y, Zhao D, Zhang X, Guo Y, Lin D. Functional polymorphisms in FAS and FASL contribute to increased apoptosis of tumor infiltration lymphocytes and risk of breast cancer. Carcinogenesis. 2007 May;28(5):1067-73. Epub 2006 Dec 20. (
  • Zhang X, Miao X, Sun T, Tan W, Qu S, Xiong P, Zhou Y, Lin D. Functional polymorphisms in cell death pathway genes FAS and FASL contribute to risk of lung cancer. J Med Genet. 2005 Jun;42(6):479-84. (


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 8, 2016