If a gene mutation runs in my family, will I inherit it?

Not necessarily. An inherited gene change is passed on only if it is present in a parent's egg or sperm cell. So among close blood relatives, some inherit the change and some do not.

According to the National Cancer Institute, genetic testing can clarify whether you carry the specific change known in your family. When possible, it is generally recommended that testing begin with a relative who has had cancer, because that gives the clearest information about whether a change is present in the family.

Even if you do carry the change, it raises risk but does not guarantee cancer — some carriers never develop it. And if a specific family change is known and your test does not find it, that is a true negative, meaning your risk is about the general-population level. A genetic counselor can help you understand what testing would mean for you.