Dr. Jane Tiller

At the moment in Australia, we're really focused on diagnostic testing and treatment-based testing.

So we offer testing to people through the public system, sometimes when they've had a cancer at a young age or a heart attack or something like that, where there are symptoms of disease that we think might be genetic, or if we're trying to guide the treatment, for example, chemotherapy in certain cancers and things.

But we really don't do very much testing at all that sits in the preventive context, which is

What we're looking at, which is this question of can we prevent disease by finding people ahead of time before they get a disease, before they have a strong enough family history to tell us, oh, this is something in the family we should be looking at.

And there are far more people out there than we had previously realized who are walking around with very high risk of preventable diseases that we could find through doing a genetic test and then offer them preventive health care.

That's exactly right.

And for a long time, we've really focused on family history as one of those indicators of who should we test because genetic testing was always very expensive.

It was very hard to figure out how we should spend that limited amount of money that we had for very expensive tests.

And so we focused on

families where we saw a lot of disease that might be genetic and we went, that's where we should spend the money.

Over time, as the cost of testing has dropped and it's become more cost effective to do this testing at the population level, we're finding that a huge number of people who are at genetic high risk don't have that family history for many reasons, maybe because they don't know their family members, maybe just because people in that family died young or just didn't get the disease.

That's absolutely right.

And genetics, you know, confers very high risk, but it's not, in most cases, it's not determinative.

Not every single person with that gene change will get the disease.

So someone might have a gene change that increases their risk, but they're lucky enough not to get it.

And so we don't see it showing up in the family.

So you're right, we looked at those things and we were aiming at looking at young adults because that is where the preventive potential is the highest.

You know, it's useful for someone who's 60 to have a genetic test in some circumstances, but those people have often lived through a lot of their risk.

So the real preventive potential sits in people in that younger age group before that age of early onset of disease.

We tested, as you said, 10,000 people, just over 10,000, and across those people, we found 202 had a high risk of disease in one of those three categories you mentioned, so hereditary cancer and heart disease risk.