According to estimates of lifetime risk, about 12.0 percent of women (120 out of 1,000) in the general population will develop breast cancer sometime during their lives compared with about 60 percent of women (600 out of 1,000) who have inherited a harmful mutation in BRCA1 or BRCA2 (breast cancer susceptibility gene 1 and breast cancer susceptibility gene 2). In other words, a woman who has inherited a harmful mutation in BRCA1 or BRCA2 is about five times more likely to develop breast cancer than a woman who does not have such a mutation.

Several methods are available to test for BRCA1 and BRCA2 mutations. Most of these methods look for changes in BRCA1 and BRCA2 DNA. At least one method looks for changes in the proteins produced by these genes. Frequently, a combination of methods is used.

Most people do not have a BRCA gene mutation (only about 1 in 800 people in the general population will have one and currently, there are no standard criteria for recommending or referring someone for BRCA1 or BRCA2 mutation testing.

In a family with a history of breast and/or ovarian cancer, it may be most informative to first test a family member who has breast or ovarian cancer. If that person is found to have a harmful BRCA1 or BRCA2 mutation, then other family members can be tested to see if they also have the mutation.

Regardless, women who have a relative with a harmful BRCA1 or BRCA2 mutation and women who appear to be at increased risk of breast and/or ovarian cancer because of their family history should consider genetic counseling to learn more about their potential risks and about BRCA1 and BRCA2 genetic tests.

The likelihood of a harmful mutation in BRCA1 or BRCA2 is increased with certain familial patterns of cancer which include the following:

You might be at increased risk of having a BRCA gene mutation — and a candidate for BRCA gene testing — if you have:

1. A personal history of breast cancer diagnosed at a young age (premenopausal), breast cancer affecting both breasts (bilateral breast cancer), or both breast and ovarian cancers
2. A family history of breast cancer at a young age in two or more close relatives, such as your parents, siblings and children
3. A family history of breast cancer in more than one generation
4. A male relative with breast cancer
5. A family member who has both breast and ovarian cancers
6. A family member with bilateral breast cancer
7. A frequent occurrence of ovarian cancer within your family
8. A positive BRCA1 or BRCA2 genetic test in a relative
9. Ashkenazi (Eastern European) Jewish ancestry, with or without a family history of breast or ovarian cancer

to learn more please go to: www.cancer.gov