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Genetics Home Reference: your guide to understanding genetic conditions
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CTNNB1

Reviewed March 2013

What is the official name of the CTNNB1 gene?

The official name of this gene is “catenin (cadherin-associated protein), beta 1, 88kDa.”

CTNNB1 is the gene's official symbol. The CTNNB1 gene is also known by other names, listed below.

What is the normal function of the CTNNB1 gene?

The CTNNB1 gene provides instructions for making a protein called beta-catenin. This protein is present in many types of cells and tissues, where it is primarily found at junctions that connect neighboring cells (adherens junctions). Beta-catenin plays an important role in sticking cells together (cell adhesion) and in communication between cells.

The beta-catenin protein is also involved in cell signaling as an essential part of the WNT signaling pathway. Certain proteins in this pathway attach (bind) to beta-catenin, which triggers a multi-step process that allows the protein to move into the nucleus. Once in the nucleus, beta-catenin interacts with other proteins to control the activity (expression) of particular genes. The WNT signaling pathway promotes the growth and division (proliferation) of cells and helps determine the specialized functions a cell will have (differentiation). WNT signaling is known to be involved in many aspects of development before birth. In adult tissues, this pathway plays a role in the maintenance and renewal of stem cells, which are cells that help repair tissue damage and can give rise to other types of cells.

Among its many activities, beta-catenin appears to play an important role in the normal function of hair follicles, which are specialized structures in the skin where hair growth occurs. This protein is active in cells that make up a part of the hair follicle known as the matrix. These cells divide and mature to form the different components of the hair follicle and the hair shaft. As matrix cells divide, the hair shaft is pushed upward and extends beyond the skin.

How are changes in the CTNNB1 gene related to health conditions?

desmoid tumor - caused by mutations in the CTNNB1 gene

Mutations in the CTNNB1 gene can cause a type of aggressive but noncancerous (benign) growth called a desmoid tumor. CTNNB1 gene mutations are found in about 85 percent of all non-inherited (sporadic) desmoid tumors. These rare tumors arise from connective tissue, which provides strength and flexibility to structures such as bones, ligaments, and muscles. The tumors are often found in the abdomen, shoulders, upper arms, or upper legs. The CTNNB1 gene mutations that cause desmoid tumors are somatic, which means they are acquired during a person's lifetime and are present only in tumor cells. Somatic mutations are not inherited.

The CTNNB1 gene mutations that cause desmoid tumors usually occur in a region of the gene called exon 3. They change single protein building blocks (amino acids) in the beta-catenin protein. These mutations lead to an abnormally stable beta-catenin protein that is not broken down when it is no longer needed. As a result, the protein accumulates within cells. Excess beta-catenin promotes the uncontrolled growth and division of cells, allowing the formation of desmoid tumors.

pilomatricoma - caused by mutations in the CTNNB1 gene

Somatic mutations in the CTNNB1 gene are found in almost all pilomatricomas, a type of benign skin tumor associated with hair follicles.

The CTNNB1 gene mutations found in pilomatricomas are described as gain-of-function mutations. They cause the beta-catenin protein to be turned on all the time (constitutively active), which leads to the abnormal activation of certain genes. These genes increase the proliferation and differentiation of cells associated with the hair follicle matrix. The cells divide too quickly and in an uncontrolled way, leading to the formation of a pilomatricoma.

Almost all pilomatricomas are benign, but a very small percentage are cancerous (malignant). The malignant version of this tumor is known as a pilomatrix carcinoma. Like pilomatricomas, pilomatrix carcinomas have somatic mutations in the CTNNB1 gene. It is unclear why some of these tumors are cancerous but most others are not.

other cancers - associated with the CTNNB1 gene

Somatic mutations in the CTNNB1 gene have been identified in several other types of cancer. These include colorectal, liver, thyroid, ovarian, endometrial, and skin cancers, as well as a type of brain tumor called a medulloblastoma, among others. Studies suggest that gain-of-function mutations in the CTNNB1 gene prevent the breakdown of beta-catenin when it is no longer needed, which allows the protein to accumulate within cells. The excess beta-catenin moves into the nucleus and promotes the unchecked growth and division of cells, allowing cancerous tumors to develop.

Because mutations in the CTNNB1 gene can cause normal cells to become cancerous, CTNNB1 belongs to a class of genes known as oncogenes. Sometimes, mutations in other oncogenes occur together with CTNNB1 gene mutations to cause cancer. It is not well understood why mutations in the CTNNB1 gene are associated with several different types of cancerous and noncancerous tumors.

Where is the CTNNB1 gene located?

Cytogenetic Location: 3p21

Molecular Location on chromosome 3: base pairs 41,199,450 to 41,240,447

The CTNNB1 gene is located on the short (p) arm of chromosome 3 at position 21.

The CTNNB1 gene is located on the short (p) arm of chromosome 3 at position 21.

More precisely, the CTNNB1 gene is located from base pair 41,199,450 to base pair 41,240,447 on chromosome 3.

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 CTNNB1?

You and your healthcare professional may find the following resources about CTNNB1 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 CTNNB1 gene or gene products?

  • armadillo
  • beta-catenin
  • catenin beta-1
  • CTNB1_HUMAN
  • CTNNB

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 CTNNB1?

acids ; benign ; breakdown ; cancer ; carcinoma ; cell ; cell adhesion ; class ; colorectal ; connective tissue ; desmoid ; differentiation ; endometrial ; exon ; gene ; hair follicle ; inherited ; medulloblastoma ; nucleus ; ovarian ; proliferation ; protein ; sporadic ; stem cells ; thyroid ; tissue ; tumor

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

References

  • Barker N. The canonical Wnt/beta-catenin signalling pathway. Methods Mol Biol. 2008;468:5-15. doi: 10.1007/978-1-59745-249-6_1. Review. (http://www.ncbi.nlm.nih.gov/pubmed/19099242?dopt=Abstract)
  • Chan EF, Gat U, McNiff JM, Fuchs E. A common human skin tumour is caused by activating mutations in beta-catenin. Nat Genet. 1999 Apr;21(4):410-3. (http://www.ncbi.nlm.nih.gov/pubmed/10192393?dopt=Abstract)
  • Ferenc T, Wroński JW, Kopczyński J, Kulig A, Sidor M, Stalińska L, Dziki A, Sygut J. Analysis of APC, alpha-, beta-catenins, and N-cadherin protein expression in aggressive fibromatosis (desmoid tumor). Pathol Res Pract. 2009;205(5):311-24. doi: 10.1016/j.prp.2008.11.002. Epub 2009 Jan 4. (http://www.ncbi.nlm.nih.gov/pubmed/19124205?dopt=Abstract)
  • Fu Y, Zheng S, An N, Athanasopoulos T, Popplewell L, Liang A, Li K, Hu C, Zhu Y. β-catenin as a potential key target for tumor suppression. Int J Cancer. 2011 Oct 1;129(7):1541-51. doi: 10.1002/ijc.26102. Epub 2011 Jun 21. Review. (http://www.ncbi.nlm.nih.gov/pubmed/21455986?dopt=Abstract)
  • Huss S, Nehles J, Binot E, Wardelmann E, Mittler J, Kleine MA, Künstlinger H, Hartmann W, Hohenberger P, Merkelbach-Bruse S, Buettner R, Schildhaus HU. β-catenin (CTNNB1) mutations and clinicopathological features of mesenteric desmoid-type fibromatosis. Histopathology. 2013 Jan;62(2):294-304. doi: 10.1111/j.1365-2559.2012.04355.x. Epub 2012 Sep 28. (http://www.ncbi.nlm.nih.gov/pubmed/23020601?dopt=Abstract)
  • Kajino Y, Yamaguchi A, Hashimoto N, Matsuura A, Sato N, Kikuchi K. beta-Catenin gene mutation in human hair follicle-related tumors. Pathol Int. 2001 Jul;51(7):543-8. (http://www.ncbi.nlm.nih.gov/pubmed/11472567?dopt=Abstract)
  • Kotiligam D, Lazar AJ, Pollock RE, Lev D. Desmoid tumor: a disease opportune for molecular insights. Histol Histopathol. 2008 Jan;23(1):117-26. Review. (http://www.ncbi.nlm.nih.gov/pubmed/17952864?dopt=Abstract)
  • Lazar AJ, Calonje E, Grayson W, Dei Tos AP, Mihm MC Jr, Redston M, McKee PH. Pilomatrix carcinomas contain mutations in CTNNB1, the gene encoding beta-catenin. J Cutan Pathol. 2005 Feb;32(2):148-57. (http://www.ncbi.nlm.nih.gov/pubmed/15606674?dopt=Abstract)
  • Lips DJ, Barker N, Clevers H, Hennipman A. The role of APC and beta-catenin in the aetiology of aggressive fibromatosis (desmoid tumors). Eur J Surg Oncol. 2009 Jan;35(1):3-10. doi: 10.1016/j.ejso.2008.07.003. Epub 2008 Aug 21. Review. (http://www.ncbi.nlm.nih.gov/pubmed/18722078?dopt=Abstract)
  • MacDonald BT, Tamai K, He X. Wnt/beta-catenin signaling: components, mechanisms, and diseases. Dev Cell. 2009 Jul;17(1):9-26. doi: 10.1016/j.devcel.2009.06.016. Review. (http://www.ncbi.nlm.nih.gov/pubmed/19619488?dopt=Abstract)
  • Moreno-Bueno G, Gamallo C, Pérez-Gallego L, Contreras F, Palacios J. beta-catenin expression in pilomatrixomas. Relationship with beta-catenin gene mutations and comparison with beta-catenin expression in normal hair follicles. Br J Dermatol. 2001 Oct;145(4):576-81. (http://www.ncbi.nlm.nih.gov/pubmed/11703283?dopt=Abstract)
  • NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/1499)
  • Tejpar S, Nollet F, Li C, Wunder JS, Michils G, dal Cin P, Van Cutsem E, Bapat B, van Roy F, Cassiman JJ, Alman BA. Predominance of beta-catenin mutations and beta-catenin dysregulation in sporadic aggressive fibromatosis (desmoid tumor). Oncogene. 1999 Nov 11;18(47):6615-20. (http://www.ncbi.nlm.nih.gov/pubmed/10597266?dopt=Abstract)
  • Xia J, Urabe K, Moroi Y, Koga T, Duan H, Li Y, Furue M. beta-Catenin mutation and its nuclear localization are confirmed to be frequent causes of Wnt signaling pathway activation in pilomatricomas. J Dermatol Sci. 2006 Jan;41(1):67-75. Epub 2005 Dec 27. (http://www.ncbi.nlm.nih.gov/pubmed/16378715?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: March 2013
Published: December 16, 2014