As a genetic counselor with 30 years of experience, I have met with many families who have been concerned about their hereditary risks to develop cancer and other disorders. I have found that the complexity of genetics can sometimes cause misunderstandings about some critical information.
A common question that patients ask is this: I already have cancer, it makes no sense for me to have genetic testing, so why don’t you test my family instead?
As it turns out, the best strategy for most families is to for genetic testing to start with a relative who has already been diagnosed with cancer.
- If that person has a normal genetic test result, there is usually no need to test any other healthy family members.
- Because of the complicated nature of cancer genetics, accurate interpretation of a negative result usually requires an affected relative to have a positive genetic test.
- If a patient has a positive genetic test, the cost of testing all other family members will usually be considerably less expensive and increases the likelihood that health insurers will cover the test.
Let’s clarify this with a specific example.
Three sisters, all in their 30s, want to undergo genetic testing because their mother is a breast cancer survivor, and ...