How Genetic Tests Can Influence Our Decisions

**Amina Serna** (0:10)
It's The Brian Lehrer Show on WNYC. I'm producer Amina Serna, filling in for Brian today.
Good morning again, everyone. Most of us think of a genetic test as a straightforward thing. You get your results, and they tell you something you can hopefully act on. But what happens when the test tells you something, and nobody, not even the lab, knows what it means? Our next guest, Elizabeth Bruenig, is a staff writer at The Atlantic, and has a new essay about exactly that. She comes from a family shaped by breast cancer. Her grandmother, her great grandmother, her great aunt, and her own mother all diagnosed. So when a doctor offered her a genetic screening, she said yes.
The good news, she carries none of the known breast cancer mutations. But the test flagged something else, what's called a quote, variant of uncertain significance on a gene linked to a rare childhood kidney cancer.
And when she asked what that meant for her two young daughters, the answer was essentially, we don't know yet. Her piece is about the fact that genetic testing can now tell us far more than science is able to interpret. And there's a very human question underneath it. When does information help us and when does it become a weight that we have to carry? Elizabeth, welcome to WNYC.

**Elizabeth Bruenig** (1:35)
Thank you for having me on.

**Amina Serna** (1:37)
And listeners, we want to hear from you. If you've gotten a genetic test result, that maybe you didn't know what to do with, in Elizabeth's circumstance, it was deemed a variant of uncertain significance. Maybe for you, it was a raised risk for something with no clear next step. Or news about a relative's genes that suddenly became your business too. Did the information help you or did it just hand you a new worry? What did you decide to do? And knowing what you know now, would you be tested again?
212-433-WNYC, that's 212-433-9692.
You can also text that number. Elizabeth, you write clinicians and patients now, quote, confront seemingly worrisome omens of possible ailments with little clarity about the actual odds of getting them or the chance of preventing them. So for listeners who have maybe spent into a 23andMe tube, the direct-to-consumer company that offers genetic testing or been offered a screening at a routine checkup, what is the gap that you're pointing to?

**Elizabeth Bruenig** (2:45)
Well, I think one of the most important things to point out is that genetic testing saves lives. There's no question about that because genetic tests can identify what are called pathogenic results. Those are mutations on genes. That researchers know come with an elevated risk for developing certain diseases. People who do test positive for those pathogenic mutations can then go to high risk clinics, which are staffed by doctors who are experienced in dealing with folks with a heightened risk for developing certain diseases like breast cancer. And they can take prophylactic steps like a double mastectomy in the case of a heightened risk for breast cancer.
But it's also possible that tests find mutations that are benign, that researchers know don't really mean anything. They're just variants that are meaningless. And then there are these variants of uncertain significance, the VUSs. Those are mutations on genes that the lab just hasn't seen enough of to know whether they are totally benign or if they're pathogenic.
And it is possible that VUSs in the future will be definitively classified as either benign or pathogenic. But in the meantime, the patient just doesn't know.

**Amina Serna** (4:08)
Let's talk a little bit about the history. You trace this whole thing back to the geneticist Marie Claire King, who spent 17 years hunting for a genetic marker before identifying the BRCA1 genetic marker in 1990
Before that, you note testing was mostly for couples worried about passing a disorder to a baby. How big of a shift was it suddenly to be able to predict, as you referred to it, ailments in living adults?

**Elizabeth Bruenig** (4:39)
It was a total sea change. As you had said, up until that time, two parents could each be genetically tested, and then they could calculate, based on their results, what the risk might be of having a child who would inherit certain diseases. But that was all genetic testing could do at that point. With Mary Claire King's research, it became possible to test grown adults for risks that they may develop ailments in the future. That gave rise to the high-risk clinics that are experienced in treating adults who have learned they have a heightened risk for developing certain diseases, which again, undoubtedly saved lives. It has saved a lot of people. I mean, it's impossible to count because health records are confidential.