Genetic Testing for Women

The New York Breast Cancer Study, published in the October 24 issue of Science reports on the high rate of cancer among a certain group of women with inherited mutations in the BRCA1 and BRCA2 genes. While the study breaks new ground about the lifetime risks of developing breast and ovarian cancer, it also provides useful information regarding medical options for women with or at risk of cancer. Jessica B. Mandell, MS, CGC genetic counselor and research coordinator for the study has provided answers to the following frequently asked questions.

Frequently Asked Questions:

Q. How do women inherit gene mutations? If I don’t have a family history of breast cancer, what are the chances that I have a mutation?

A. Women inherit mutations of the BRCA1 and BRCA2 genes from their parents. A lack of family history of cancer does not necessarily mean that you do not have a mutation in one of these genes that instruct the cells of the breast and ovary to grow at a slow and regular rate. (Cell growth and division at an increased rate can lead to cancer.) Since an altered gene may come from your father, and the incidence of developing cancer among men is significantly smaller, family history may not be enough of an indication to determine whether or not you carry a mutation.

Q. How do I know if I have a mutation in the BRCA1 or BRCA2 gene?

A. The only way to find out is to receive genetic testing. Genetic testing is performed by taking a small blood sample and screening it for possible mutations in the BRCA genes. While hundreds of possible BRCA mutations exist, and mutations have been found in populations around the world, certain BRCA mutations are more prevalent among individuals from specific ancestries. The New York Breast Cancer Study, based on Ashkenazi Jewish women with breast cancer, focused genetic testing on the three most common BRCA mutations because these are the most frequent mutations in the Ashkenazi population.

Q. I think I am at an increased risk for carrying a BRCA mutation. Where do I go for genetic counseling and genetic testing?

A. The first step is to meet with a genetic counselor or medical professional who can provide you with a medical and family history risk assessment and the necessary information about testing to determine if genetic testing is right for you. It is important to receive this detailed information before testing to review the benefits and limitations of the test, the implications of the results, opportunities for follow-up medical services, and the meaning of test results for both the individual and the family. Genetic testing is a specialized test, not intended for the general population of women, even if they are of Ashkenazi Jewish background, unless they have had cancer or there is cancer in their family. Pre-test counseling will help clarify if you are an appropriate candidate.

Q. What is a genetic counselor?

A. Genetic counselors are specially trained medical professionals who work as members of a health care team, providing information and support to families at risk for a variety of inherited conditions or who have members affected by genetic conditions and birth defects. Genetic counselors identify families at risk, investigate the situation present in the family, interpret information about the medical disorder, analyze inheritance patterns and risks of recurrence and review available medical and social options with the family. Genetic counselors also provide supportive counseling to families, serve as patient advocates and refer individuals and families to community or state support services.

Q. How do I find a genetic counselor?

A. Most major medical centers today have a cancer department or a genetic counseling department with access to genetic counselors that specialize in cancer. To find a genetic counselor in your area, you can also contact the National Society of Genetic Counselors website.

For more information about genetic counseling please see the Sarah Lawrence College Graduate Program in Human Genetics web site.