How to build your family tree before a genetics appointment | CION Cancer Clinics

Because a spoken family history leaves out details that change the whole picture, and a drawn tree makes gaps and patterns visible at a glance. A counsellor reads shapes on that tree the way a radiologist reads a scan.

What a tree captures that conversation misses

Who was diagnosed, at what age, with what exact cancer, and on which side of the family, all sit on the tree together. Said aloud, these details blur; drawn out, a pattern of young diagnoses on one side of the family becomes obvious immediately.

You do not need to be exact to start

Approximate ages and best-guess relationships are still useful. A counsellor will help fill gaps and flag anything worth confirming later. Waiting until you have perfect information before booking an appointment only delays a conversation that can start productively today. Families often spend weeks trying to track down an exact age or diagnosis before calling anyone, when a rough version handed over at the first visit would have moved things along just as well.

Why this step comes before any discussion of testing

A counsellor cannot judge whether testing is worth considering without first seeing the shape of the family. A tree that looks ordinary can rule testing out quickly, saving a family the cost and wait of a test that was never going to change anything. A tree that shows a real pattern does the opposite, and moves the conversation toward testing sooner rather than later.

It cannot tell you whether your particular family tree shows a concerning pattern. That judgment depends on the actual ages, cancer types and relationships involved, which only a counsellor reviewing your specific tree can assess properly.

It cannot replace calling relatives yourself

No template or checklist can recover information that only a family member remembers. The single most useful thing you can do before an appointment is have those conversations, even briefly, with an older relative. A short call to an aunt or an older cousin often surfaces a diagnosis nobody else in the immediate family knew about, and that one detail can change the whole assessment.

Who this does not apply to

If your family history is already well documented and was recently reviewed by a genetics clinic, you likely do not need to rebuild the tree from scratch. Bring the existing version instead.