Skip Navigation
Genetics Home Reference: your guide to understanding genetic conditions  
 
http://ghr.nlm.nih.gov/     A service of the U.S. National Library of Medicine®

BRCA1

Breast cancer 1, early onset

What is the normal function of the BRCA1 gene?

The BRCA1 gene belongs to a class of genes known as tumor suppressor genes. Like many other tumor suppressor genes, BRCA1 regulates the cycle of cell division by keeping cells from growing and dividing too rapidly or in an uncontrolled way. In particular, it inhibits the growth of cells that line the milk ducts in the breast.

The protein made by the BRCA1 gene is directly involved in the repair of damaged DNA. In the nucleus of many types of normal cells, the BRCA1 protein interacts with the protein produced by the RAD51 gene to mend breaks in DNA. These breaks can be caused by natural radiation or other exposures, but also occur when chromosomes exchange genetic material in preparation for cell division. The BRCA2 protein, which has a function similar to that of BRCA1, also interacts with the RAD51 protein. By repairing DNA, these three proteins play a role in maintaining the stability of the human genome.

Research suggests that both the BRCA1 and BRCA2 proteins regulate the activity of other genes and play a critical role in embryo development. The BRCA1 protein probably interacts with many other proteins, including tumor suppressors and regulators of the cell division cycle.

These genes interact to repair damaged DNA.

  • BRCA1:breast cancer 1, early onset
  • BRCA2:breast cancer 2, early onset
  • RAD51:RAD51 homolog (RecA homolog, E. coli) (S. cerevisiae)

What conditions are related to the BRCA1 gene?

breast cancer - increased risk from variations of the BRCA1 gene

Researchers have identified more than 600 mutations in the BRCA1 gene, many of which are associated with an increased risk of cancer. These mutations can be changes in one or a small number of DNA base pairs (the building blocks of DNA). In some cases, large segments of DNA are rearranged. A mutated BRCA1 gene usually makes a protein that does not function properly because it is abnormally short. Researchers believe that the defective BRCA1 protein is unable to help fix mutations that occur in other genes. These defects accumulate and may allow cells to grow and divide uncontrollably to form a tumor.

other cancers - increased risk from variations of the BRCA1 gene

In addition to breast cancer, mutations in the BRCA1 gene also increase the risk of ovarian, prostate, and colon cancers.

Where is the BRCA1 gene located?

17q21

The BRCA1 gene is located on the long (q) arm of chromosome 17 at position 21.

The BRCA1 gene is located on the long (q) arm of chromosome 17 at position 21.

See "How do geneticists indicate the location of a gene?" in the Handbook (http://ghr.nlm.nih.gov/info=basics/show/gene_location).

Where can I find information about BRCA1?

You and your healthcare professional may find the following resources about BRCA1 helpful.

  • Educational resources - Information pages
    National Cancer Institute Genetics of Breast and Ovarian Cancer (http://www.cancer.gov/cancertopics/pdq/genetics/breast-and-ovarian/HealthProfessional/page1)
  • ClinicalTrials.gov - Linking patients to medical research (http://www.clinicaltrials.gov/ct/search?term=BRCA1)
  • Gene Reviews - Clinical summary (http://www.genetests.org/query?dz=brca1)
  • Gene Tests - DNA tests ordered by healthcare professionals (http://www.genetests.org/query?testid=2422)

You may also be interested in these resources, which are designed for genetics professionals and researchers.

  • PubMed - Recent literature (http://ghr.nlm.nih.gov/gene=brca1/show/PubMed)
  • OMIM - Genetic disorder catalog (http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=113705)
  • Research Resources - Tools for researchers
    • GeneCards (http://genecards.weizmann.ac.il/cgi-bin/cards/carddisp?BRCA1)
    • HUGO Gene Nomenclature Committee (http://www.gene.ucl.ac.uk/cgi-bin/nomenclature/get_data.pl?hgnc_id=1100)
    • Locus Link (http://www.ncbi.nlm.nih.gov/LocusLink/LocRpt.cgi?l=672)

What other names do people use for the BRCA1 gene or gene products?

  • BRC1_HUMAN
  • BRCA1 Genes
  • Breast Cancer 1 Gene
  • Breast Cancer, Type 1
  • Breast cancer type 1 susceptibility protein
  • breast-ovarian cancer, included
  • Hereditary Breast Cancer 1

See "How are genetic conditions and genes named?" in the Handbook (http://ghr.nlm.nih.gov/info=mutations_and_disorders/show/naming).

What glossary definitions help with understanding BRCA1?

base pair ; cancer ; cell division ; cell division cycle ; chromosome ; colon ; DNA ; DNA base ; duct ; embryo ; gene ; genome ; homologs ; mutation ; nucleus ; prostate ; protein ; Radiation ; susceptibility ; tumor ; tumor suppressor gene

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

 
Sources for this page

  • 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. Epub 2003 Apr 03. Erratum in: Am J Hum Genet. 2003 Sep;73(3):709. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db;=pubmed&dopt;=Abstract&list;_uids=12677558)
  • Barnett GL, Friedrich CA. Recent developments in ovarian cancer genetics. Curr Opin Obstet Gynecol. 2004 Feb;16(1):79-85. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db;=pubmed&dopt;=Abstract&list;_uids=15128012)
  • Daniel DC. Highlight: BRCA1 and BRCA2 proteins in breast cancer. Microsc Res Tech. 2002 Oct 1;59(1):68-83. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db;=pubmed&dopt;=Abstract&list;_uids=12242698)
  • Ding SL, Sheu LF, Yu JC, Yang TL, Chen BF, Leu FJ, Shen CY. Abnormality of the DNA double-strand-break checkpoint/repair genes, ATM, BRCA1 and TP53, in breast cancer is related to tumour grade. Br J Cancer. 2004 May 17;90(10):1995-2001. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db;=pubmed&dopt;=Abstract&list;_uids=15138484)
  • Foulkes WD, Metcalfe K, Sun P, Hanna WM, Lynch HT, Ghadirian P, Tung N, Olopade OI, Weber BL, McLennan J, Olivotto IA, Begin LR, Narod SA. Estrogen receptor status in BRCA1- and BRCA2-related breast cancer: the influence of age, grade, and histological type. Clin Cancer Res. 2004 Mar 15;10(6):2029-34. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db;=pubmed&dopt;=Abstract&list;_uids=15041722)
  • Liede A, Karlan BY, Narod SA. Cancer risks for male carriers of germline mutations in BRCA1 or BRCA2: a review of the literature. J Clin Oncol. 2004 Feb 15;22(4):735-42. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db;=pubmed&dopt;=Abstract&list;_uids=14966099)
  • Metcalfe K, Lynch HT, Ghadirian P, Tung N, Olivotto I, Warner E, Olopade OI, Eisen A, Weber B, McLennan J, Sun P, Foulkes WD, Narod SA. Contralateral breast cancer in BRCA1 and BRCA2 mutation carriers. J Clin Oncol. 2004 Jun 15;22(12):2328-35. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db;=pubmed&dopt;=Abstract&list;_uids=15197194)
  • Powell SN, Kachnic LA. Roles of BRCA1 and BRCA2 in homologous recombination, DNA replication fidelity and the cellular response to ionizing radiation. Oncogene. 2003 Sep 1;22(37):5784-91. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db;=pubmed&dopt;=Abstract&list;_uids=12947386)
  • Scully R, Puget N. BRCA1 and BRCA2 in hereditary breast cancer. Biochimie. 2002 Jan;84(1):95-102. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db;=pubmed&dopt;=Abstract&list;_uids=11900881)
  • Tutt A, Ashworth A. The relationship between the roles of BRCA genes in DNA repair and cancer predisposition. Trends Mol Med. 2002 Dec;8(12):571-6. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db;=pubmed&dopt;=Abstract&list;_uids=12470990)
  • Venkitaraman AR. Cancer susceptibility and the functions of BRCA1 and BRCA2. Cell. 2002 Jan 25;108(2):171-82. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db;=pubmed&dopt;=Abstract&list;_uids=11832208)

 

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 (http://ghr.nlm.nih.gov/info=consultation/show/finding_professional).
 
Last Comprehensive Review: September 2004
Updated: September 30, 2004
Published: October 8, 2004
Contact NLM Customer ServiceThis link leads to a site outside Genetics Home Reference.
Lister Hill National Center for Biomedical CommunicationsThis link leads to a site outside Genetics Home Reference.
U.S. National Library of MedicineThis link leads to a site outside Genetics Home Reference., National Institutes of HealthThis link leads to a site outside Genetics Home Reference., Department of Health & Human ServicesThis link leads to a site outside Genetics Home Reference.
Freedom of Information ActThis link leads to a site outside Genetics Home Reference. CopyrightThis link leads to a site outside Genetics Home Reference. PrivacyThis link leads to a site outside Genetics Home Reference. AccessibilityThis link leads to a site outside Genetics Home Reference. FirstGov.govThis link leads to a site outside Genetics Home Reference.
For selection criteria for web links, see Genetics Home Reference at http://ghr.nlm.nih.gov/
This link leads to a site outside Genetics Home Reference. Indicates a page outside Genetics Home Reference.