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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.

Read more about gene names and symbols on the About page.

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) (NCBIThis link leads to a site outside Genetics Home Reference.)

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

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 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.

See also Understanding Medical Terminology.

References (15 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: July 2014
Published: February 8, 2016