BRCA2 Gene

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This entry is adapted from the peer-reviewed paper https://medlineplus.gov/genetics/gene/brca2

BRCA2, DNA repair associated

genes

1. Normal Function

The BRCA2 gene provides instructions for making a protein that acts as a tumor suppressor. Tumor suppressor proteins help prevent cells from growing and dividing too rapidly or in an uncontrolled way.

The BRCA2 protein is involved in repairing damaged DNA. In the nucleus of many types of normal cells, the BRCA2 protein interacts with several other proteins to mend breaks in DNA. These breaks can be caused by natural and medical radiation or other environmental exposures, and they also occur when chromosomes exchange genetic material in preparation for cell division. By helping to repair DNA, the BRCA2 protein plays a critical role in maintaining the stability of a cell's genetic information.

Researchers suspect that the BRCA2 protein has additional functions within cells. For example, the protein may help regulate cytokinesis, which is the step in cell division when the fluid surrounding the nucleus (the cytoplasm) divides to form two separate cells. Researchers are investigating the protein's other potential activities.

2. Health Conditions Related to Genetic Changes

2.1. Breast Cancer

Mutations in the BRCA2 gene are associated with an increased risk of breast cancer in both men and women, as well as several other types of cancer. These mutations are present in every cell in the body and can be passed from one generation to the next. As a result, they are associated with cancers that cluster in families. However, not everyone who inherits a mutation in the BRCA2 gene will develop cancer. Other genetic, environmental, and lifestyle factors also contribute to a person's cancer risk.

Most BRCA2 gene mutations lead to the production of an abnormally small, nonfunctional version of the BRCA2 protein from one copy of the gene in each cell. As a result, less of this protein is available to help repair damaged DNA or fix mutations that occur in other genes. As these defects accumulate, they can trigger cells to grow and divide uncontrollably to form a tumor.

2.2. Ovarian Cancer

Many of the same BRCA2 gene mutations that increase the risk of breast cancer (described above) also increase the risk of ovarian cancer. Families with these mutations are often said to be affected by hereditary breast and ovarian cancer syndrome. Women with BRCA2 gene mutations have an approximately 12 to 25 percent chance of developing ovarian cancer in their lifetimes, as compared with 1.6 percent in the general population.

2.3. Prostate Cancer

Inherited BRCA2 gene mutations have been found to increase the risk of prostate cancer. Men with these mutations are also more likely to develop prostate cancer at an earlier age and may be at increased risk of having an aggressive form of the disease. They may also be at increased risk for other cancers.

BRCA2 gene mutations likely reduce the BRCA2 protein's ability to repair DNA, allowing potentially damaging mutations to persist in various other genes. The accumulation of damaging mutations can lead to the out-of-control cell growth and division that can result in development of a tumor.

2.4. Cholangiocarcinoma

Cholangiocarcinoma

2.5. Fanconi Anemia

Fanconi anemia

2.6. Other Cancers

Inherited mutations in the BRCA2 gene also increase the risk of several other types of cancer, including pancreatic cancer and an aggressive form of skin cancer called melanoma. These mutations impair the ability of the BRCA2 protein to help repair damaged DNA. As defects accumulate in DNA, they can trigger cells to grow and divide without order to form a tumor. It is not clear why different individuals with BRCA2 mutations develop cancers in different organs. Environmental factors that affect specific organs may contribute to the development of cancers at particular sites.

3. Other Names for This Gene

brca 2 gene
BRCA2_HUMAN
BRCC2
breast cancer 2
breast cancer 2 gene
breast cancer 2, early onset
breast cancer 2, early onset gene
breast cancer type 2 susceptibility gene
breast cancer type 2 susceptibility protein
FACD
FAD
FAD1
FANCB
FANCD1

References

Chen S, Parmigiani G. Meta-analysis of BRCA1 and BRCA2 penetrance. J ClinOncol. 2007 Apr 10;25(11):1329-33.
Foulkes WD, Shuen AY. In brief: BRCA1 and BRCA2. J Pathol. 2013Aug;230(4):347-9. doi: 10.1002/path.4205. Review.
Foulkes WD. BRCA1 and BRCA2 - update and implications on the genetics ofbreast cancer: a clinical perspective. Clin Genet. 2014 Jan;85(1):1-4. doi:10.1111/cge.12291.Mar;85(3):302.
Friebel TM, Domchek SM, Rebbeck TR. Modifiers of cancer risk in BRCA1 andBRCA2 mutation carriers: systematic review and meta-analysis. J Natl Cancer Inst.2014 Jun;106(6):dju091. doi: 10.1093/jnci/dju091. Review. Erratum in: J NatlCancer Inst. 2014 Aug;106(8):dju235 doi:10.1093/jnci/dju235.
Kobayashi H, Ohno S, Sasaki Y, Matsuura M. Hereditary breast and ovariancancer susceptibility genes (review). Oncol Rep. 2013 Sep;30(3):1019-29. doi:10.3892/or.2013.2541.
National Cancer Institute: Genetics of Breast and Gynecologic Cancers (PDQ®)–Health Professional Version
Nelson HD, Fu R, Goddard K, Mitchell JP, Okinaka-Hu L, Pappas M, Zakher B.Risk Assessment, Genetic Counseling, and Genetic Testing for BRCA-Related Cancer:Systematic Review to Update the U.S. Preventive Services Task ForceRecommendation [Internet]. Rockville (MD): Agency for Healthcare Research andQuality (US); 2013 Dec. Available fromhttp://www.ncbi.nlm.nih.gov/books/NBK179201/
Pennington KP, Swisher EM. Hereditary ovarian cancer: beyond the usualsuspects. Gynecol Oncol. 2012 Feb;124(2):347-53. doi:10.1016/j.ygyno.2011.12.415. Review.
Petrucelli N, Daly MB, Pal T. BRCA1- and BRCA2-Associated Hereditary Breastand Ovarian Cancer. 1998 Sep 4 [updated 2016 Dec 15]. In: Adam MP, Ardinger HH,Pagon RA, Wallace SE, Bean LJH, Stephens K, Amemiya A, editors. GeneReviews®[Internet]. Seattle (WA): University of Washington, Seattle; 1993-2020. Availablefrom http://www.ncbi.nlm.nih.gov/books/NBK1247/
Shahid T, Soroka J, Kong E, Malivert L, McIlwraith MJ, Pape T, West SC, Zhang X. Structure and mechanism of action of the BRCA2 breast cancer tumor suppressor.Nat Struct Mol Biol. 2014 Nov;21(11):962-968. doi: 10.1038/nsmb.2899.
Shulman LP. Hereditary breast and ovarian cancer (HBOC): clinical features andcounseling for BRCA1 and BRCA2, Lynch syndrome, Cowden syndrome, and Li-Fraumeni syndrome. Obstet Gynecol Clin North Am. 2010 Mar;37(1):109-33, Table of Contents.doi: 10.1016/j.ogc.2010.03.003. Review.
Toss A, Tomasello C, Razzaboni E, Contu G, Grandi G, Cagnacci A, Schilder RJ, Cortesi L. Hereditary ovarian cancer: not only BRCA 1 and 2 genes. Biomed ResInt. 2015;2015:341723. doi: 10.1155/2015/341723.
Wagner JE, Tolar J, Levran O, Scholl T, Deffenbaugh A, Satagopan J, Ben-Porat L, Mah K, Batish SD, Kutler DI, MacMillan ML, Hanenberg H, Auerbach AD. Germline mutations in BRCA2: shared genetic susceptibility to breast cancer, early onsetleukemia, and Fanconi anemia. Blood. 2004 Apr 15;103(8):3226-9.

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Subjects: Genetics & Heredity

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Vicky Zhou

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Update Date: 24 Dec 2020

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