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BRCA1

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.

Where can I find information about BRCA1?

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

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 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.

 
Sources for this page (11 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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