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BRCA2

BRCA2

Breast cancer 2, early onset

What is the normal function of the BRCA2 gene?

The BRCA2 gene is a tumor suppressor gene involved in the repair of chromosomal damage. Tumor suppressor genes regulate the cycle of cell division by keeping cells from growing and dividing too rapidly or in an uncontrolled way.

Although the structures of the BRCA1 and BRCA2 genes are very different, their functions appear to be similar. The proteins made by both genes are essential for repairing damaged DNA. The BRCA2 protein binds to and regulates the protein produced by the RAD51 gene to fix breaks in DNA. These breaks can be caused by natural and medical radiation or other environmental exposures, but also occur when chromosomes exchange genetic material during a special type of cell division that creates sperm and eggs (meiosis). The BRCA1 protein also interacts with the RAD51 protein. By repairing DNA, these three proteins play a role in maintaining the stability of the human genome.

Like BRCA1, BRCA2 probably regulates the activity of other genes and plays a critical role in embryo development.

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 BRCA2 gene?

breast cancer - increased risk from variations of the BRCA2 gene

Researchers have identified about 450 mutations in the BRCA2 gene, many of which cause an increased risk of cancer. BRCA2 mutations are usually insertions or deletions of a small number of DNA base pairs (the building material of chromosomes) in the gene. As a result of these mutations, the protein product of the BRCA2 gene is abnormally short and does not function properly. Researchers believe that the defective BRCA2 protein is unable to help fix mutations that occur in other genes. As a result, mutations build up and can cause cells to divide in an uncontrolled way and form a tumor.

other disorders - caused by mutations in the BRCA2 gene

People who have two mutated copies of the BRCA2 gene have one type of Fanconi anemia. This condition is caused by extremely reduced levels of the BRCA2 protein in cells, which allows the accumulation of damaged DNA. Patients with Fanconi anemia are prone to several types of leukemia (a type of blood cell cancer); solid tumors, particularly of the head, neck, skin, and reproductive organs; and bone marrow suppression (reduced blood cell production that leads to anemia).

other cancers - increased risk from variations of the BRCA2 gene

In addition to breast cancer in men and women, mutations in BRCA2 also lead to an increased risk of ovarian, prostate, and pancreatic cancers. In particular, mutations in the central part of the gene have been associated with a higher risk of ovarian cancer and a lower risk of prostate cancer than mutations in other parts of the gene. As mutations build up, they can cause cells to divide in an uncontrolled way and form a tumor. Several other types of cancer have also been seen in families with BRCA2 mutations.

Where is the BRCA2 gene located?

13q12.3

The BRCA2 gene is located on the long (q) arm of chromosome 13 at position 12.3.

The BRCA2 gene is located on the long (q) arm of chromosome 13 at position 12.3.

See How do geneticists indicate the location of a gene? in the Handbook.

Where can I find information about BRCA2?

You and your healthcare professional may find the following resources about BRCA2 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 BRCA2 gene or gene products?

  • BRC2_HUMAN
  • brca 2 gene
  • Breast Cancer 2 Gene
  • Breast Cancer, Type 2
  • Breast cancer type 2 susceptibility protein
  • FACD
  • FAD
  • FAD1
  • FANCB
  • FANCD1
  • Hereditary Breast Cancer 2

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding BRCA2?

anemia ; base pair ; bone marrow ; cancer ; cell division ; chromosome ; deletion ; DNA ; DNA base ; embryo ; gene ; genome ; homologs ; insertion ; leukemia ; meiosis ; mutation ; prostate ; protein ; Radiation ; susceptibility ; tumor ; tumor suppressor gene

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

 
Sources for this page (16 links)

 

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.

 
Last Comprehensive Review: September 2004
Updated: September 30, 2004
Published: October 18, 2004

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