Whole Genome Sequencing Is Here To Stay. What Does That Mean For Genetic Privacy?
Originally published on Wednesday, February 26, 2014. Updated to include audio from St. Louis on the Air.
It cost billions of dollars and took more than a decade to sequence the first human genome.
That was more than ten years ago. Our understanding of human genetics has advanced considerably since then, and these days anybody can find out a lot about their genetic make-up just by sending in a sample of their DNA in the mail.
But with our genetic information becoming increasingly easier to access, what does that mean for genetic privacy?
They participated in a panel discussion on genetic privacy at Washington University’s Brown School on Tuesday.
Whole genome sequencing involves mapping all of your genetic material: the roughly three billion base pairs ― or building blocks ― that make up your DNA. University of Chicago physician and medical ethicist Lainie Friedman Ross says right now, it’s mainly done in children with developmental disabilities.
“In my field of pediatrics, for example, we use it when we have a child who has a condition for which we don’t have a diagnosis, and we can’t figure it out with any of the more traditional means,” Ross said.
Whole genome sequencing can give doctors access to a new source of medical insight about their patients. But the ethics of how to handle all that personal genetic information is still evolving.
One big question is what to do with what are known as “incidental findings." That's the term used when doctors discover genetic information that whole genome sequencing uncovers but that’s unrelated to the patient’s current condition.
Washington University physician and geneticist Laura Jean Bierut explains it this way:
“If you’re looking for an issue with developmental disability, or a congenital syndrome, you might find something else in the person’s genome. You may find that they are at risk for breast cancer, at risk for colon cancer, at risk for a variety of other diseases. And so there’s this issue about, what do we do with these incidental findings. Do we return these to the patients?”
In other words, should doctors tell the patients about their potentially disease-causing mutations?
It’s a question that has engendered a lot of controversy. But Bierut believes patients should be informed if they have mutations in the five dozen or so genes that existing research has strongly linked to disease.
Ross disagrees. She says we still don’t know enough about what so-called “high risk” genetic variations really mean, or how they interact with environmental factors.
“When we look in low-risk families, it turns out some of them have those genes, and may never go on to develop the health problem. So we’re now creating, in a sense, patients-in-waiting, people who are waiting…for the rock to fall, and the rock may never fall. And so we’re creating a lot of anxiety. And remember, these are conditions that we’re not expecting even to present for decades, when medicine will have evolved a lot, and it might make more sense to wait before we have that information.”
Bierut has a different perspective.
“I think it’s the question of whether the glass is half full or glass is half empty. I think at this point we have a tremendous amount of information about many of these genes. Is it perfect at this point in time? Absolutely not. Are we going to find more information about new variants that are pathogenic? Absolutely. Are we going to understand that the risk of some of these variants is less? Absolutely. However, the risk for many of these variants is quite high.”
Bierut gives the example of child who undergoes whole genome sequencing. It’s discovered that she has a BRCA mutation, one that has been linked to a high risk of breast and ovarian cancer in adults. (You may remember Angelina Jolie writing about having the mutation, last year.)
Since the child has the variant, Bierut says, that means one of her parents does, too.
“It’s true that the child will not develop the disease for a long time,” Bierut said. “But you have a parent standing there in front of you. And you have information about that parent. And it is this balance about what do you do.”
I asked Ross whether she agreed that the parent would benefit from finding out about their child’s genetic mutation.
“So the answer is maybe,” Ross said. “Turns out that in high-risk families…about 80 percent, or four out of five people who have the gene will go on to develop breast cancer.” But she says for some people, the risk is much lower: about one in three.
“That's still a high risk,” Ross said. “But remember those of us who don't have BRCA, we have a one in nine chance of getting breast cancer. So were not changing the risk that much.”
Bierut counters that we have an obligation to use the genetic knowledge we already have. And she says in the future, it will only get easier for people to discover their genetic make-up ― whether doctors want them to, or not.
Through direct-to-consumer testing, anyone can already send a sample of their DNA to one of several companies that will analyze it and send back at least some of your genetic information. I asked Bierut and Ross what they thought about this new development in how people can access their genetic information. Not surprisingly, they disagree.
“You’ve removed the physician/genetic counselor intermediary. Several years ago I was not a believer in this. I was very concerned about the information that was going to be given. As I am looking at it more and more, I really see this is most likely going to be the wave of the future.”
“And why is it going to be the wave of the future? One is, an individual can chose to take the test or not. It is their freedom to do this.”
“The second aspect…of this is I think genetic revolution is coming. I think that we all agree that genetics is entering medicine…”
“Now we have information in there and should we give that back to people? Do individuals want it to be given back? And in general the answer to this has been is yes. Over 500,000 people have been tested with 23andMe...The type of genetic counseling that can be given is over the internet. It is a new type of information being given…It is scalable ― tremendous amount of information ― and we know we do not have enough genetic counselors at this time to give the face to face counseling we’ve historically given.”
“When you get into the health care world, we have standards. We have evidence-based standards. And so one of the things that we see is somebody like [National Institutes of Health Director] Francis Collins sends three of his samples to three different companies. And at one company he’s told has increased risk for prostate cancer, and at another company he’s told he’s at a decreased risk for prostate cancer.”
“And so why does he get different information? Is one company better than the other? And the answer is, he is getting different information because as we keep collecting more and more information, our understanding of the fact that it’s not one gene that causes prostate cancer, but there are many genes and how these genes interact. But these genes also interact with the environment.”
“And 23andMe is not collecting environmental information. So their data ― they’re giving you a very specific increased risk ― is totally wrong. I mean it may be increased, it may be decreased. But until you can combine, not just the genetic information with other genetic information but also with environmental risk, with dietary, with your socioeconomic, with whether your mother was pregnant and drank in pregnancy or was starved during pregnancy. All of these will have health implications for whether you will develop prostate cancer as an older man.”
When asked to sum up their assessment of what the new developments in accessing and revealing genetic information means to individuals, Bierut said: “We are undergoing a genetic revolution, and I see genetics entering medicine. Our goal should be to see how do we have it enter medicine safely, efficiently, effectively. And part of that, I see, will be the information is given to individuals.”
Ross doesn’t see things that way. She says there’s still too much we don’t understand.
“We understand one gene/one disease. What we don't understand is, there are modifiers within the genome and various environmental modifiers. And we don't understand any of this," Ross said. "So we keep giving this very accurate, specific information, when really the accurate information is, it's ambiguous; we still don't know enough. But we're giving you a very specific…relative risk compared to other people, and that's just wrong.”
Follow Véronique LaCapra on Twitter: @KWMUScience