The BRCA1 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 BRCA1 protein is involved in repairing damaged DNA. In the nucleus of many types of normal cells, the BRCA1 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 BRCA1 protein plays a critical role in maintaining the stability of a cell's genetic information.
Research suggests that the BRCA1 protein also regulates the activity of other genes and plays an essential role in embryonic development. To carry out these functions, the BRCA1 protein interacts with many other proteins, including other tumor suppressors and proteins that regulate cell division.
Health Conditions Related to Genetic Changes
Mutations in the BRCA1 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 BRCA1 gene will develop cancer. Other genetic, environmental, and lifestyle factors also contribute to a person's cancer risk.
Most BRCA1 gene mutations lead to the production of an abnormally short version of the BRCA1 protein or prevent any protein from being made from one copy of the gene. 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.More About This Health Condition
Many of the same BRCA1 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 BRCA1 gene mutations have a 35 to 60 percent chance of developing ovarian cancer in their lifetimes, as compared with 1.6 percent in the general population.More About This Health Condition
Inherited BRCA1 gene mutations have been found to increase the risk of prostate cancer. These mutations likely reduce the BRCA1 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 cause a tumor to develop. Men who carry a BRCA1 gene mutation may also be at increased risk for other cancers, including breast and pancreatic cancer.More About This Health Condition
MedlinePlus Genetics provides information about CholangiocarcinomaMore About This Health Condition
Inherited mutations in the BRCA1 gene also increase the risk of several other types of cancer, including pancreatic cancer and colon cancer. These mutations impair the ability of the BRCA1 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 BRCA1 mutations develop cancers in different organs. Environmental factors that affect specific organs may contribute to the development of cancers at particular sites.
Other Names for This Gene
- BRCA1 gene
- breast cancer 1
- breast cancer 1 gene
- breast cancer 1, early onset
- breast cancer 1, early onset gene
- breast cancer type 1 susceptibility gene
- breast cancer type 1 susceptibility protein
Additional Information & Resources
Tests Listed in the Genetic Testing Registry
Scientific Articles on PubMed
Catalog of Genes and Diseases from OMIM
- Antoniou A, Pharoah PD, Narod S, Risch HA, Eyfjord JE, Hopper JL, Loman N, Olsson H, Johannsson O, Borg A, Pasini B, Radice P, Manoukian S, Eccles DM, Tang N, Olah E, Anton-Culver H, Warner E, Lubinski J, Gronwald J, Gorski B, Tulinius H, Thorlacius S, Eerola H, Nevanlinna H, Syrjakoski K, Kallioniemi OP, Thompson D, Evans C, Peto J, Lalloo F, Evans DG, Easton DF. Average risks of breast and ovarian cancer associated with BRCA1 or BRCA2 mutations detected in case Series unselected for family history: a combined analysis of 22 studies. Am J Hum Genet. 2003 May;72(5):1117-30. doi: 10.1086/375033. Epub 2003 Apr 3. Erratum In: Am J Hum Genet. 2003 Sep;73(3):709. Citation on PubMed or Free article on PubMed Central
- Chen S, Parmigiani G. Meta-analysis of BRCA1 and BRCA2 penetrance. J Clin Oncol. 2007 Apr 10;25(11):1329-33. doi: 10.1200/JCO.2006.09.1066. Citation on PubMed or Free article on PubMed Central
- Foulkes WD, Shuen AY. In brief: BRCA1 and BRCA2. J Pathol. 2013 Aug;230(4):347-9. doi: 10.1002/path.4205. Citation on PubMed
- Foulkes WD. BRCA1 and BRCA2 - update and implications on the genetics of breast cancer: a clinical perspective. Clin Genet. 2014 Jan;85(1):1-4. doi: 10.1111/cge.12291. Epub 2013 Oct 25. No abstract available. Erratum In: Clin Genet. 2014 Mar;85(3):302. Citation on PubMed
- Friebel TM, Domchek SM, Rebbeck TR. Modifiers of cancer risk in BRCA1 and BRCA2 mutation carriers: systematic review and meta-analysis. J Natl Cancer Inst. 2014 Jun;106(6):dju091. doi: 10.1093/jnci/dju091. Erratum In: J Natl Cancer Inst. 2014 Aug;106(8):dju235 doi:10.1093/jnci/dju235. Citation on PubMed or Free article on PubMed Central
- Kobayashi H, Ohno S, Sasaki Y, Matsuura M. Hereditary breast and ovarian cancer susceptibility genes (review). Oncol Rep. 2013 Sep;30(3):1019-29. doi: 10.3892/or.2013.2541. Epub 2013 Jun 19. Citation on PubMed
- 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 Force Recommendation [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2013 Dec. Report No.: 12-05164-EF-1. Available from http://www.ncbi.nlm.nih.gov/books/NBK179201/ Citation on PubMed
- Oh M, McBride A, Yun S, Bhattacharjee S, Slack M, Martin JR, Jeter J, Abraham I. BRCA1 and BRCA2 Gene Mutations and Colorectal Cancer Risk: Systematic Review and Meta-analysis. J Natl Cancer Inst. 2018 Nov 1;110(11):1178-1189. doi: 10.1093/jnci/djy148. Citation on PubMed
- Pennington KP, Swisher EM. Hereditary ovarian cancer: beyond the usual suspects. Gynecol Oncol. 2012 Feb;124(2):347-53. doi: 10.1016/j.ygyno.2011.12.415. Citation on PubMed
- Petrucelli N, Daly MB, Pal T. BRCA1- and BRCA2-Associated Hereditary Breast and Ovarian Cancer. 1998 Sep 4 [updated 2022 May 26]. In: Adam MP, Mirzaa GM, Pagon RA, Wallace SE, Bean LJH, Gripp KW, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2023. Available from http://www.ncbi.nlm.nih.gov/books/NBK1247/ Citation on PubMed
- Shulman LP. Hereditary breast and ovarian cancer (HBOC): clinical features and counseling 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. Citation on PubMed
- 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 Res Int. 2015;2015:341723. doi: 10.1155/2015/341723. Epub 2015 May 17. Citation on PubMed or Free article on PubMed Central
- Walsh T, Casadei S, Coats KH, Swisher E, Stray SM, Higgins J, Roach KC, Mandell J, Lee MK, Ciernikova S, Foretova L, Soucek P, King MC. Spectrum of mutations in BRCA1, BRCA2, CHEK2, and TP53 in families at high risk of breast cancer. JAMA. 2006 Mar 22;295(12):1379-88. doi: 10.1001/jama.295.12.1379. Citation on PubMed
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