I Don’t Know My Family History. Can I Still Get Tested?

Almost every article about hereditary cancer risk begins with the same instruction: know your family history. But what if you do not have one? If you are adopted, estranged from biological relatives, have a small family, or come from a family where cancer was not discussed openly, you may feel excluded from the entire conversation. You are not excluded. And the lack of a family history may actually make genetic testing more valuable for you, not less.

Why Family History Is Usually the Starting Point

Family history is a proxy, not the thing itself. It is an indirect indicator of whether a hereditary variant might be present. When family history is unavailable, the underlying question remains: do you carry a hereditary cancer gene variant? That question can be answered directly through genetic testing.

Testing Without Family History

Ancestry-based criteria may apply. Individuals of Ashkenazi Jewish descent have an approximately 1 in 40 chance of carrying a BRCA founder mutation, regardless of family history.

Personal history may qualify you. If you have been diagnosed with cancer yourself — particularly breast cancer before age 65, ovarian cancer at any age, or colorectal cancer before age 50 — testing is recommended based on your own diagnosis.

Population screening is gaining support. Research supports offering genetic testing more broadly, beyond the traditional guideline-based approach. Learn about who should consider genetic testing.

What Testing Can Give You

For someone without a family history, genetic testing provides something especially powerful: a baseline. Either way, you move from “unknown” to informed. If you have taken a consumer DNA test for ancestry purposes, those results are not a substitute for clinical-grade hereditary cancer testing.

Starting the Process

A clinical risk assessment is designed to work with incomplete information. Genetic counselors are trained to evaluate risk in the context of unknown or limited family histories. You do not need a complete family tree to take action. Learn about the genetic testing process or read about overcoming the fear of testing.