Jennifer is a 32-year-old woman in a serious relationship, who doesn't yet have children. She receives a letter from her mother's sister, her aunt Dorothy, who was recently diagnosed with breast cancer and undergoing treatment.

Aunt Dorothy is 48 years old. Her own mother — Jennifer's grandmother — was also diagnosed with breast cancer at a young age (47). Learning that breast cancer before age 50 was a risk factor for hereditary breast and ovarian cancer convinced Dorothy to get genetic testing.

Dorothy has both her BRCA1 and BRCA2 genes sequenced, to try to locate any mutations that are known to be associated with breast and ovarian cancer risk. The test results reveal that Dorothy indeed has a deleterious mutation in the BRCA2 gene.

Jennifer knows how genes run in families: As sisters, her aunt and her mother have a 50 percent chance of carrying the same gene, and thus, the same mutation. Jennifer, who has inherited half of her mother's genes, has a 25 percent chance of having the same mutation as her aunt.

Normally, Jennifer's mother might be the next person in the family to get tested. If her mother doesn't have the mutation, Jennifer and her siblings will be free of it, too. But since her mother died in a car accident, Jennifer is left to consider testing herself.

At this point in her life, she's not sure it's the right time to undergo genetic testing. So, she decides to talk to a genetic counselor to learn about her options as well as the steps she can take to reduce her risk for disease.

Jennifer's Decision

After talking to the counselor, Jennifer learns that if she were to go ahead with genetic testing, the most appropriate method for her would be single-site analysis.

Since Dorothy's DNA sequencing has revealed the mutation causing her family's cancers, Jennifer's only needs to test for that specific mutation in one BRCA gene (rather than the range of mutations across both BRCA1 and BRCA2 that DNA sequencing detects).

Jennifer understands that if single-site analysis reveals a mutation, she has inherited the increased risk for breast and ovarian cancer that runs in her family and can talk to her doctor about taking steps to reduce her risk for these diseases.

If, on the other hand, single-site analysis does not detect a mutation, Jennifer will know that she has not inherited this risk. She can simply follow the screening guidelines recommended for the general population, because her cancer risk is no greater than that of someone without a family history of cancer.

After considering all of her options, Jennifer decides to delay genetic testing. Because she's currently between jobs, she's worried that a positive test result might jeopardize her health and life insurance.

She plans to undergo single-site analysis after her job situation has stabilized. In the meantime, Jennifer has decided to take birth control to decrease her risk for ovarian cancer and has worked out a screening plan for breast and ovarian cancer with her physician.