Reviewed August 2007
What is the official name of the BRCA1 gene?
The official name of this gene is “breast cancer 1, early onset.”
BRCA1 is the gene's official symbol. The BRCA1 gene is also known by other names, listed below.
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 suppressors, the protein produced from the BRCA1 gene helps prevent cells from growing and dividing too rapidly or in an uncontrolled way.
The BRCA1 gene provides instructions for making a protein that is directly involved in repairing damaged DNA. In the nucleus of many types of normal cells, the BRCA1 protein interacts with several other proteins, including the proteins produced from the RAD51 and BARD1 genes, to mend breaks in DNA. These breaks can be caused by natural and medical radiation or other environmental exposures, and also occur when chromosomes exchange genetic material in preparation for cell division. By helping repair DNA, BRCA1 plays a 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 a critical 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.
Does the BRCA1 gene share characteristics with other genes?
The BRCA1 gene belongs to a family of genes called RNF (RING-type zinc fingers).
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 BRCA1 gene related to health conditions?
- breast cancer - increased risk from variations of the BRCA1 gene
Researchers have identified more than 1,000 mutations in the BRCA1 gene, many of which are associated with an increased risk of cancer (particularly breast cancer in women). Most of these 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. Other BRCA1 mutations change single protein building blocks (amino acids) in the protein or delete large segments of DNA from the BRCA1 gene. Researchers believe that a defective or missing BRCA1 protein is unable to help repair damaged DNA or fix mutations that occur in other genes. As these defects accumulate, they can allow cells to grow and divide uncontrollably and form a tumor.
- other cancers - increased risk from variations of the BRCA1 gene
In addition to female breast cancer, mutations in the BRCA1 gene also increase the risk of several other types of cancer including fallopian tube cancer, male breast cancer, and pancreatic cancer. Many of these mutations change one of the amino acids used to make the BRCA1 protein, resulting in a protein that cannot perform its normal DNA repair function.
Where is the BRCA1 gene located?
Cytogenetic Location: 17q21
Molecular Location on chromosome 17: base pairs 43,044,294 to 43,125,482
The BRCA1 gene is located on the long (q) arm of chromosome 17 at position 21.
More precisely, the BRCA1 gene is located from base pair 43,044,294 to base pair 43,125,482 on chromosome 17.
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 BRCA1?
You and your healthcare professional may find the following resources about BRCA1 helpful.
Educational resources - Information pages
- Cancer Medicine (sixth edition, 2003): BRCA1 and BRCA2: Gene Structure and Function (http://www.ncbi.nlm.nih.gov/books/NBK12959/)
- National Cancer Institute: Genetics of Breast and Ovarian Cancer (PDQ) (http://www.cancer.gov/cancertopics/pdq/genetics/breast-and-ovarian/HealthProfessional/page1)
- Gene Reviews - Clinical summary (http://www.ncbi.nlm.nih.gov/books/NBK1247)
Genetic Testing Registry - Repository of genetic test information
- GTR: Genetic tests for BRCA1 (http://www.ncbi.nlm.nih.gov/gtr/tests/?term=672%5Bgeneid%5D)
You may also be interested in these resources, which are designed for genetics professionals and researchers.
- PubMed - Recent literature (http://www.ncbi.nlm.nih.gov/pubmed?term=%28%28BRCA1%5BMAJR%5D%29%20AND%20%28BRCA1%5BTI%5D%29%29%20AND%20%28genes%5BMH%5D%29%20AND%20review%5Bpt%5D%20AND%20english%5Bla%5D%20AND%20human%5Bmh%5D%20AND%20%22last%20360%20days%22%5Bdp%5D)
- OMIM - Genetic disorder catalog (http://omim.org/entry/113705)
Research Resources - Tools for researchers
- Atlas of Genetics and Cytogenetics in Oncology and Haematology (http://atlasgeneticsoncology.org/Genes/BRCA1ID163ch17q21.html)
- Cancer Genetics Web: BRCA1 (http://www.cancerindex.org/geneweb/BRCA1.htm)
- GeneCards (http://www.genecards.org/cgi-bin/carddisp.pl?id_type=entrezgene&id=672)
- HGNC Gene Symbol Report (http://www.genenames.org/cgi-bin/gene_symbol_report?q=data/hgnc_data.php&hgnc_id=1100)
- NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/672)
What other names do people use for the BRCA1 gene or gene products?
- BRCA1 gene
- Breast Cancer 1, Early Onset Gene
- Breast Cancer 1 Gene
- Breast Cancer, Type 1
- Breast Cancer Type 1 Susceptibility Gene
- Breast cancer type 1 susceptibility protein
- breast-ovarian cancer, included
- Hereditary Breast Cancer 1
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 BRCA1?
cell division ;
DNA repair ;
susceptibility gene ;
You may find definitions for these and many other terms in the Genetics Home Reference
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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
See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.