Testing Family Members

For Patients & Parents

Genetic testing can cause many emotions for family members. Some people might feel better after learning their risk of cancer and other diseases. Other people might worry about their cancer risk or feel they have no control over the future. Each person should decide whether to be tested or tell other family members about the test results.

Some family members choose to have genetic testing because the results can help them decide about cancer screening, treatment, or whether to have children in the future. Other people want to learn where the cancer came from. Some families choose not to have genetic testing because they believe knowing about a mutation would make them worry. Some families are just not interested in genetic testing.

If you or your family members aren’t sure about whether to have genetic testing, it can help to talk about it together. You can also talk with doctors, genetic counselors, and advisors like friends or spiritual leaders. You can have a genetic test any time, so if you are not sure about testing now, you can have it later.

The law says people under 18 cannot decide for themselves about having genetic testing. If your child has cancer, you or your child’s legal guardian must decide if testing is right for your child. Older children and teenagers should have as much choice as possible in this decision. Some scientists do not recommend genetic testing for children under 18 who have not had cancer. These children can decide about genetic testing when they are over 18.

If you have a family history of cancer, genetic testing could make life better. Scientists have learned that people whose families have Li-Fraumeni syndrome (LFS) and know they have the TP53 mutation have benefited from tests that find small tumors before they grow and spread.

Once you have decided to have genetic testing, tell your child’s doctor or genetic counselor so they can guide you through the next steps. Some common feelings about test results are listed below.

Positive test results for a TP53 mutation might:

  • Make it easier to test other family members,
  • Make you feel better because you know the reason for the cancer,
  • Help doctors make treatment decisions, and
  • Help you decide about having children in the future.

If you or your child have a positive result, you might:

  • Worry about your cancer risk or your children’s risk,
  • Feel guilty about passing on the mutation,
  • Feel in control because you can avoid things that cause cancer and get regular tests and checkups to look for cancer, or
  • Worry about getting life or health insurance.

If you or your child have a negative result, you might feel:

  • Relieved that you and your family don’t have an increased cancer risk,
  • Unsure about why cancer happened in your child,
  • Isolated from family members who have positive test results, or
  • Upset that your child has the mutation and cancer instead of you.