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Genetics Home Reference: your guide to understanding genetic conditions
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IL7R

Reviewed April 2013

What is the official name of the IL7R gene?

The official name of this gene is “interleukin 7 receptor.”

IL7R is the gene's official symbol. The IL7R gene is also known by other names, listed below.

What is the normal function of the IL7R gene?

The IL7R gene provides instructions for making a protein called interleukin 7 (IL-7) receptor alpha chain. This protein is one piece of both the IL-7 receptor and the thymic stromal lymphopoietin (TSLP) receptor. These receptors are embedded in the cell membrane of immune system cells. The IL-7 receptor is found in B cells and T cells as well as the early blood-forming cells that give rise to them. The TSLP receptor is found in several types of immune cells, including B cells, T cells, monocytes, and dendritic cells. These cells identify foreign substances and defend the body against infection and disease.

At the cell surface, the IL-7 receptor interacts with a protein called IL-7. IL-7 is a cytokine, which is a protein that regulates the activity of immune system cells. The receptor and cytokine fit together like a lock and its key, triggering a series of chemical signals inside the cell. In early blood-forming cells, signaling through the IL-7 receptor ensures the development of mature B cells and T cells. IL-7 receptor signaling also stimulates the later growth and division (proliferation) and survival of these cells.

Similarly, the TSLP receptor interacts with the cytokine TSLP. Attachment of TSLP to its receptor triggers a set of signals that support proliferation and maturation of a variety of immune system cells.

Does the IL7R gene share characteristics with other genes?

The IL7R gene belongs to a family of genes called CD (CD molecules). It also belongs to a family of genes called fibronectin type III domain containing (fibronectin type III domain containing). It also belongs to a family of genes called IL (interleukins and interleukin receptors).

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? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genefamilies) in the Handbook.

How are changes in the IL7R gene related to health conditions?

multiple sclerosis - associated with the IL7R gene

A common variation of the IL-7R gene increases the risk of developing multiple sclerosis. This condition affects the brain and spinal cord (central nervous system), causing muscle weakness, poor coordination, numbness, and a variety of other health problems. The genetic variation involved in multiple sclerosis affects a single protein building block (amino acid) in the IL-7 receptor alpha chain, specifying the amino acid isoleucine at position 244 instead of the amino acid threonine (written as Thr244Ile). The IL-7 receptor that contains this version of the alpha chain is not embedded in the cell surface but is instead found inside the cell. It is not clear if this alpha chain variant affects the TSLP receptor.

Because the IL7R gene is involved in regulation of the immune system, changes in it might be involved in the autoimmune response and inflammation that damage nerves and the protective coating surrounding them (the myelin sheath), leading to the signs and symptoms of multiple sclerosis. (Autoimmunity occurs when the immune system malfunctions and attacks the body's own tissues and organs, in this case tissues of the nervous system.) However, it is unclear exactly what role the IL-7R gene variant plays in development of multiple sclerosis. It is likely that a combination of genetic and environmental factors is involved.

other disorders - caused by mutations in the IL7R gene

Mutations in the IL7R gene can cause a form of severe combined immunodeficiency (SCID), in which affected individuals have decreased immune function and are prone to recurrent and persistent infections. Affected individuals with IL7R gene mutations have few or no T cells but normal numbers of B cells and another type of immune cell called NK cells. This form of the condition is called T-B+NK+ SCID. Many IL7R gene mutations that cause SCID prevent the production of the IL-7 receptor alpha chain, which impairs IL-7 receptor and TSLP receptor signaling. Without this signaling, development of T cells is disrupted. A lack of T cells reduces the immune system's ability to fight infections, leading to recurrent infections in people with T-B+NK+ SCID.

Mutations in the IL7R gene can also cause cancers of blood-forming cells, specifically B-cell acute lymphoblastic leukemia (ALL), which is characterized by elevated numbers of B cells in the blood, and T-cell ALL, characterized by elevated numbers of T cells. The mutations associated with these cancers lead to an altered IL-7 receptor alpha chain. With this alteration, signaling pathways like those triggered by the IL-7 receptor or the TSLP receptor are constantly turned on (constitutively active) even without cytokine interaction. Constant signaling increases proliferation and survival of B cells or T cells, leading to ALL.

Where is the IL7R gene located?

Cytogenetic Location: 5p13

Molecular Location on chromosome 5: base pairs 35,856,874 to 35,879,602

The IL7R gene is located on the short (p) arm of chromosome 5 at position 13.

The IL7R gene is located on the short (p) arm of chromosome 5 at position 13.

More precisely, the IL7R gene is located from base pair 35,856,874 to base pair 35,879,602 on chromosome 5.

See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.

Where can I find additional information about IL7R?

You and your healthcare professional may find the following resources about IL7R 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 IL7R gene or gene products?

  • CD127
  • CD127 antigen
  • CDW127
  • IL7RA
  • IL-7RA
  • IL7RA_HUMAN
  • IL-7R-alpha
  • IL-7 receptor subunit alpha
  • IL-7R subunit alpha
  • ILRA
  • interleukin 7 receptor alpha chain
  • interleukin 7 receptor isoform H5-6
  • interleukin-7 receptor subunit alpha
  • interleukin-7 receptor subunit alpha precursor

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What glossary definitions help with understanding IL7R?

acute ; acute lymphoblastic leukemia ; amino acid ; autoimmune ; autoimmunity ; cell ; cell membrane ; central nervous system ; cytokine ; gene ; genetic variation ; immune system ; immunodeficiency ; infection ; inflammation ; isoleucine ; leukemia ; myelin sheath ; nervous system ; NK cells ; precursor ; proliferation ; protein ; receptor ; sclerosis ; subunit ; threonine

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

  • Akashi K, Kondo M, Weissman IL. Role of interleukin-7 in T-cell development from hematopoietic stem cells. Immunol Rev. 1998 Oct;165:13-28. Review. (http://www.ncbi.nlm.nih.gov/pubmed/9850848?dopt=Abstract)
  • Corfe SA, Paige CJ. The many roles of IL-7 in B cell development; mediator of survival, proliferation and differentiation. Semin Immunol. 2012 Jun;24(3):198-208. doi: 10.1016/j.smim.2012.02.001. Epub 2012 Mar 14. Review. (http://www.ncbi.nlm.nih.gov/pubmed/22421572?dopt=Abstract)
  • Giliani S, Mori L, de Saint Basile G, Le Deist F, Rodriguez-Perez C, Forino C, Mazzolari E, Dupuis S, Elhasid R, Kessel A, Galambrun C, Gil J, Fischer A, Etzioni A, Notarangelo LD. Interleukin-7 receptor alpha (IL-7Ralpha) deficiency: cellular and molecular bases. Analysis of clinical, immunological, and molecular features in 16 novel patients. Immunol Rev. 2005 Feb;203:110-26. Review. (http://www.ncbi.nlm.nih.gov/pubmed/15661025?dopt=Abstract)
  • Gregory SG, Schmidt S, Seth P, Oksenberg JR, Hart J, Prokop A, Caillier SJ, Ban M, Goris A, Barcellos LF, Lincoln R, McCauley JL, Sawcer SJ, Compston DA, Dubois B, Hauser SL, Garcia-Blanco MA, Pericak-Vance MA, Haines JL; Multiple Sclerosis Genetics Group. Interleukin 7 receptor alpha chain (IL7R) shows allelic and functional association with multiple sclerosis. Nat Genet. 2007 Sep;39(9):1083-91. Epub 2007 Jul 29. (http://www.ncbi.nlm.nih.gov/pubmed/17660817?dopt=Abstract)
  • He R, Geha RS. Thymic stromal lymphopoietin. Ann N Y Acad Sci. 2010 Jan;1183:13-24. doi: 10.1111/j.1749-6632.2009.05128.x. Review. (http://www.ncbi.nlm.nih.gov/pubmed/20146705?dopt=Abstract)
  • OMIM: INTERLEUKIN 7 RECEPTOR (http://omim.org/entry/146661)
  • Lundmark F, Duvefelt K, Iacobaeus E, Kockum I, Wallström E, Khademi M, Oturai A, Ryder LP, Saarela J, Harbo HF, Celius EG, Salter H, Olsson T, Hillert J. Variation in interleukin 7 receptor alpha chain (IL7R) influences risk of multiple sclerosis. Nat Genet. 2007 Sep;39(9):1108-13. Epub 2007 Jul 29. (http://www.ncbi.nlm.nih.gov/pubmed/17660816?dopt=Abstract)
  • NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/3575)
  • Puel A, Ziegler SF, Buckley RH, Leonard WJ. Defective IL7R expression in T(-)B(+)NK(+) severe combined immunodeficiency. Nat Genet. 1998 Dec;20(4):394-7. (http://www.ncbi.nlm.nih.gov/pubmed/9843216?dopt=Abstract)
  • Shochat C, Tal N, Bandapalli OR, Palmi C, Ganmore I, te Kronnie G, Cario G, Cazzaniga G, Kulozik AE, Stanulla M, Schrappe M, Biondi A, Basso G, Bercovich D, Muckenthaler MU, Izraeli S. Gain-of-function mutations in interleukin-7 receptor-α (IL7R) in childhood acute lymphoblastic leukemias. J Exp Med. 2011 May 9;208(5):901-8. doi: 10.1084/jem.20110580. Epub 2011 May 2. Erratum in: J Exp Med. 2011 May 9;208(5):preceding 901. J Exp Med. 2011 Jun 6;208(6):1333. (http://www.ncbi.nlm.nih.gov/pubmed/21536738?dopt=Abstract)
  • Zenatti PP, Ribeiro D, Li W, Zuurbier L, Silva MC, Paganin M, Tritapoe J, Hixon JA, Silveira AB, Cardoso BA, Sarmento LM, Correia N, Toribio ML, Kobarg J, Horstmann M, Pieters R, Brandalise SR, Ferrando AA, Meijerink JP, Durum SK, Yunes JA, Barata JT. Oncogenic IL7R gain-of-function mutations in childhood T-cell acute lymphoblastic leukemia. Nat Genet. 2011 Sep 4;43(10):932-9. doi: 10.1038/ng.924. (http://www.ncbi.nlm.nih.gov/pubmed/21892159?dopt=Abstract)

 

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? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: April 2013
Published: December 16, 2014