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Main page General info BRCA1 and BRC2 Links BRCA1 and BRCA2 : Breast cancer genesHereditary forms of breast cancer constitute only about 5% to 7% of the total cases of breast cancers. However this is an important topic because, once a woman inherits one of the genetic mutations, there is a high chance of that woman developing breast cancer. Screening of women who have inherited breast cancer related genetic mutation, and testing of their family members are very important because of substantial increase in the risk of development of breast cancer in these women. The most common genetic mutations which increases the risk of breast cancer include breast cancer associated gene 1 (BRCA1) and breast cancer associated gene 2 (BRCA2. Identification and characterization of these two genes has markedly improved our understanding of breast cancer genetics. Commercial testing is available to detect the presence of these genetic mutations. The services of a trained genetic councilor is available in many larger centers to guide the patients through the process of genetic testing and resolving many of the social issues related with genetic testing. BRCA1 and BRCA2 carriers also have an increased risk of development of breast cancer at a younger age. When a young woman develops breast cancer the possibility of BRCA1 or BRCA2 mutation should always be explored. The chance of having a BRCA1 or BRCA2 mutation increased markedly if the young woman have relatives with breast cancer who have developed breast cancer or ovarian cancer at an early age. BRCA1 associated breast cancer tends to be higher-grade compared to breast cancer that develop without BRCA1 mutation. These cancers also tend to be hormone receptor negative, however it is not clear if the overall out come is different from breast cancer not associated with BRCA mutations. BRCA2 associated breast cancer tends to resemble the regular mutation unrelated breast cancer in most respects. The incidence of BRCA1 and BRCA2 mutation in the general population is not very clear. It is estimated that in the general population the incidence of BRCA1 mutation is between 1 in 500 and 1 in 800. The incidence of BRCA2 mutation is even lower. Most of the information that we have on these genes have come from studies of high risk populations. BRCA1 and BRCA2 mutations are much more common in the Ashkenazi Jews. 1 in 40 of individuals with Ashkenazi Jewish background may be have mutation in the BRCA1 or BRCA2 mutation. The most common mutation in BRCA1 is called 185delAG. A 40-year-old woman from Ashkenazi ancestry with a history of breast cancer has about 20 percent to 30 percent chance of having a genetic mutation in one of these genes. BRCA1 and BRC2 Other resources for breast cancer |