Baylor College of Medicine

Body of Work: Spit it Out, Part One


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Show Notes


What is the difference between clinical genetic testing and an at-home genetic test kit? What can you learn about yourself through your genetic information? What does that knowledge mean for your health? Bioethicist Dr. Amy McGuire weighs in.

Amy McGuire, J.D., Ph.D., is a professor of biomedical ethics and director of the Center for Medical Ethics and Health Policy at Baylor College of Medicine. Her professional interests include ethical and policy issues raised by emerging technologies, research ethics, informed consent and confidentiality.

See more information on Baylor College of Medicine’s clinical genetic testing program.

See below for some of the research studies mentioned in the episode:


Spit it Out (Part 1): The Reality of At-Home Genetic Testing | Transcript



Erin: Welcome to Body of Work, an exploration of health topics in the news and important issues facing science with experts from Baylor College of Medicine. I’m Erin Blair, and my guest today is bioethicist Dr. Amy McGuire.

So we're talking about the proliferation of at-home genetic testing and the ethical implications of swabbing your cheek or otherwise providing a sample, sending it off in the mail, and getting back information about yourself. What could go wrong with that? When do you remember these at home kits first being marketed?

Dr. McGuire: In 2007, 23andme, which is one of the biggest companies that offers these direct-to-consumer genetic testing kits, hit the markets. It got a lot of publicity because 23andme was founded by the wife of one of the founders of Google so it had quite a bit of large financial backing to it. I remember reading about that in 2007 and being really fascinated by this movement. I think I wrote the for my first paper thinking about some of the issues related to this it was published

in 2008. That year we did a survey of individuals to say what do you think of this? Do you think this is a good idea? What are you concerned about? That was published in 2009. Those first early years we were kind of looking at this with a lot of curiosity thinking, along with everybody else in our field, is this a good thing? is this a bad thing? how is this going to turn out? what are people going to think of this?

Erin: Traditionally, a genetic test has been a clinical environment?

Dr. McGuire: Yeah, so traditionally when you have a concern about a particular condition that might run in your family, the method of getting testing is to go to your doctor and they'll typically refer you to a genetic counselor. They'll talk about sort of what your specific risks might be with and without genetic testing. When they do the genetic testing in a health care environment, they're really putting the results into context of everything else. One thing that we really need to understand is that genetics is, for the most part, with the exception of some really significant Mendelian disorders where if you have a gene you're going to get a disorder... and a clear example of that is something like Huntington's disease. People who are at risk of Huntington's disease if they have an affected parent. For example, they have a 50% chance of inheriting the gene themselves, and if they inherit it then they know that they're going to get Huntington's disease. There aren't very many diseases or disorders like that. Most of the things we test for from a genetic perspective are really complex, and you need to understand the results in the context of your family history, of your current symptoms, of sort of what your environmental exposures are, etc. When you get those tests done with a licensed health care professional, typically a genetic counselor or geneticists, will spend a lot of time doing a family history with you and looking at sort of how the results might fit into your bigger picture. On the other hand, when you do it through a direct-to-consumer genetic testing service, they're not looking at the whole picture. They're just giving you the genetic results back, and then it's your job to try to figure out what that means for you as an individual.

Erin: How specific are these results? How detailed is the report back to the consumer?

Dr. McGuire: Well, it depends on the company. We're talking about these as if they're one size fits all. There are a lot of different companies who offer a lot of different services. Some of the companies that are out there are not actually focused on health-related information. They're more focused on things like genetic genealogy where they want to try to map you to what parts of the world did your ancestors come from, and they can link you to people who you might be related to. There are other companies out there who might provide interpretive services, and then there's companies like 23andme, which again is one of the biggest companies that's out there, that kind of does a little bit of everything. They'll provide ancestry information. They provide information for what a lot of people refer to as "recreational genetics", so things like do you have a gene that's been associated with having a lot of ear wax or baldness. Usually curiosities that aren't really health-related in any real sense of the word. Then, they're also offering personal health information. The types of personal health information that a company like 23andme offers is risk information about very complex and common diseases like: are you at increased risk of heart disease or diabetes, or things that we see very frequently in the population based just on your genetics. Of course, we know that regardless of what your genetics says about those types of disorders a lot of it has to do with your lifestyle, your environment, your diet, and your exercise. They'll also provide information that is a little bit more predictive. Things like BRCA mutations which have been shown to be fairly highly relevant to your risk of getting breast and ovarian cancer. It depends on the company in terms of what report you get back but typically it's done online. You get information about your risk level and some of the companies have sort of color-coded schemes where they say you're at high risk, medium risk or low risk based on the findings that they have.

Erin: How could someone misinterpret these results?

Dr. McGuire: I think there's a couple ways that these results can be misinterpreted. The first is that there's the potential that somebody could not understand the significance of genetic information and how it fits into the bigger picture. They could get a report back that says based on their genetics they're at increased risk over the general population for heart disease later in their life. They could interpret that to mean I'm going get heart disease and get really upset about that. If we educate people well, I think we can minimize the risk of that because the fact of the matter is that's not what the report is actually telling you. I think most of the companies do a pretty good job of educating their customers that that's not what the results mean. Another way that people can misinterpret the results is that they don't understand what's actually being tested for. Let's take 23andme that's testing for the BRCA mutation. There are thousands of mutations in the BRCA gene that have been shown to be associated with increased risk of breast or ovarian cancer. They test for the three most common variants in the BRCA gene. They miss ninety percent of the variants. So, somebody could get a result, and it could be negative on their test. They could assume that they're not at risk but they're not accounting for the fact that they could have one of those other 90 percent of variants. So, they could neglect to follow up with more increased screening, especially if they have a family history of breast or ovarian cancer. There's also the possibility of false positives. Most of the companies are pretty good at giving you analytic validity, so there actually aren't a whole lot of false positives. But, what a lot of people end up doing is, if the company isn't testing for a certain variance, they'll send their genetic information to a third-party interpreter. There have been a lot of reports of third-party interpreters interpreting that information incorrectly.

Erin: Can you see any benefits to at-home genetic testing?

Dr. McGuire: Absolutely. I think a lot of people are very, very curious and we all constantly want to seek information out about ourselves. I don't think that's a bad thing. I think that's actually a good thing. We're very curious about: Who am I? I think that's sort of the fundamental existential question we all have. Who am I? What makes me, me? Those sorts of questions. So, I do think that there's benefits in that regard, just from a curiosity perspective for many of the things that people are looking at. I think there's also a benefit to the extent that many of these companies do ancestry testing and things like that. People also want connection they want to know not only: Who am I? but Who are my people? That's just a function of being human. You hear really interesting stories of people who get connected to a relative that they didn't know existed, or a part of their family from a whole different part of the world that they that they never knew, or adoptees who find their biological parents. You hear good and bad stories about that, but certainly people who are interested in that information find it useful. I have a colleague who knew for forever that his father was an anonymous sperm donor, and he donated sperm to put himself through medical school, and he's now gone on these direct-to-consumer genetic testing websites and has identified two half-siblings and connected with them, has a great relationship with them. Those two half siblings did not know that they were the product of sperm donation, but they feel really fortunate to now have this sort of new, extended family. You hear stories like that and I think that can be really beneficial to individuals. I also think from a health perspective there is the possibility that those who may not know that they're an increased risk for certain disorders could find out that information and it could encourage them to either make changes in their life, or to go see a physician, or to follow up on something. We do hear cases of that as well.

Erin: Have you had genetic testing done?

Dr. McGuire: I have not used a direct-to-consumer genetic testing company, not because I'm opposed to it, but I just haven't done it. I did get offered several years ago by one of my colleagues. doing a research study and was doing not the same kind of genetic testing that the companies are currently doing which is what we call snip arrays. They're looking at the single changes in your genome over thousands of sites in your genome, but they're not looking at the whole thing. I'm not reading the whole book. So this was a particular study where they were reading the whole book. They were doing a whole genome sequencing. My colleague asked me if I would be interested in participating in the study, and I would get back the results of that. It was really interesting because I'm a big proponent of research. I decided at the moment: you can take my blood and you can use it for your research but I'm not so sure yet if I want the results back. I'll tell you a little bit about why I felt that way. At the time, this was about five years ago, I hadn't really thought through the implications of this, but I have a family history of neurodegenerative diseases. My mother has Parkinson's disease, and my grandfather had Alzheimer's disease. So, I wanted to think a little bit about what I want to know if I had a genetic predisposition to either one of those diseases. I thought like I would go back to my office and I kind of do what you know people in my position, bioethicists and lawyers, do we make lists of the pros and cons, and we make a very rational decision. It turned out to be a five-year journey of thinking very carefully about who I am and what it means to be me. It was sort of an existential journey of coming to terms with what would this information mean for me. It was really interesting to me that I went through that because I know probably as well as anybody else that intellectually I know that nothing that they could tell me from my whole genome sequence would tell me whether I was going to get Parkinson's disease or Alzheimer's disease. We don't have a gene that tells us you're going to get this particular disorder for Parkinson's or Alzheimer's. I knew that really well, and yet I was still very concerned that whatever the results were, they would change how I felt about myself. It would change the things that I expected of myself. It might change my relationship to my kids and how they felt their obligations were to me later in life or things like that. So, I spent a long time thinking about that and I didn't get my results back for many years. I did recently get them back. The reason I got them back is because I decided that I wanted to have my mother have her genome sequence because they didn't really know what they were looking for in me unless they knew what she had. So, both my mother and father had their genome sequenced. Once they got their results back, which they shared with me, I felt comfortable kind of going and saying: "okay, now we know what we're looking for if we're looking for anything and I'm comfortable sort of putting that information into context for me individually". I had also gotten to the point where I really felt like I could take that information in and not only understand it intellectually and understand it emotionally what that information was telling me.

Erin: You worked with the genetic counselor through all of this?

Dr. McGuire: I worked with a geneticist, yes.

Erin: If you had gone through or 23andme, how much of your journey would have been different?

Dr. McGuire: I certainly couldn't have done the test and then spent the time thinking about whether I wanted the results, in the same way. In some ways, it's not that dissimilar. I've actually had a 23andme kit that somebody bought me, which is another interesting story sitting in my house for three years, as I've gone through this journey thinking about do I want to send this in? and what do I want to find out? I haven't sent it in, but it doesn't mean I will never send it in but that was part of it. You have to make that decision before you actually go and have the test done. I will say that I think 23andme does have a couple of findings like risk of Alzheimer's disease that we think might be particularly sensitive for people. If they may not want to know, there's an extra sort of click-through when you go online to get your results and you have to click and agree to see those results. They can mask those if you decide you don't want them. You could later go back and look at them if you would like to.

Erin: If you go to see a genetic counselor versus getting your results online from your at-home test, what kind of a qualitative difference do you have in the information and the kind of understanding you have of what your results mean?

Dr. McGuire: When you get a clinical genetic test, typically you have quite a bit of counseling around what those results might mean for you in the context of your life and your family history and your current situation. When you do a direct-to-consumer genetic test, typically, you get the results on a computer screen and the burden is on you to go consult with somebody who can he can help you figure out what that means. Now, I think some of the companies are thinking about ways in which they can offer genetic counseling services more remotely to their customers and can provide sort of referrals and things like that. Hopefully we'll move more in that direction. For the most part the burden is more on the consumer to take the information if they have a positive result to go get it validated clinically, If they have a finding that they're confused about to go seek out the expertise that can help them understand it.

Erin: What about a clinical genetic test? Is that experience usually captured in a moment? Say they're helping you make a decision about whether to have children or not because of some condition that is in your family. Is it pinpointed on that condition or is it an ongoing relationship with the patient afterwards?

Dr. McGuire: It's typically a one-time test. There's a lot of discussion right now in the profession and in the field about what we ought to be doing about reinterpretation. The science is moving very quickly. Our understanding of genetics and different variants and what they mean for health and disease is advancing very quickly. So, every year there's sort of new variants that are coming up that we say: now we understand that either this variant is significant for disease or we thought it was significant for disease but now we have enough evidence that we know that it's really not significant for disease. It is important for people to get updated information. The challenge with that is that it puts a very large burden on the laboratory to continually update everybody's interpretive information, and there isn't really a way to pay for that. So, it's not something that you can submit to insurance for reimbursement to reinterpret this to see if there's any new information. There's also a challenge losing contact with patients. So, we might get new information about them, but we have no way of communicating it to them. This has been a really big challenge for the field, and I think we're still trying to figure out how to do that. There certainly is a recognition that we do need to be updating information regularly because of just the pace of scientific discovery in this space.

Erin: That does raise the question of: do these at home tests have any updating system where they go back to their customers and say: hey since we did your screening we've learned this, that or the other that might affect your results or how you think about your health going forward?

Dr. McGuire: That's a really good question. I'm actually not a hundred percent sure of the answer, but I don't think that they update your particular results. What people can do is they can sort of download all of their information from most of these companies, and there's this whole industry out there now of "third-party interpreters" where you can upload your results to them and over time they can reinterpret your results as often as you want. Now, again, there have been some issues with the validity of those findings. There have been cases that have been in the media talking about people who have gotten results back from those third-party interpreters that have ended up being false positives or things that have caused them quite a lot of anxiety, or concern that they've later gone to the medical establishment tried to get confirmed and it didn't confirm. So, I would be a little bit wary and careful about what service you're using and how much weight you put on those findings unless you go and get a second opinion.

Erin: Do you have any sense of how frequently people go back to their health care providers with the information they've gotten and say what does this mean? How can you fix me? Is doing the test at home still leading back to a conversation with your doctor about your health?

Dr. McGuire: That's a very interesting question. Most physicians don't have anything to really say on the basis of these results. So if it's a particularly concerning finding, they may want to redo the test in a clinical environment, validate it, and make sure that it's correct. Most of the findings, like I said, that people are getting are increased risk of common and complex disorders. So the clinicians advice would be something like: eat better, exercise more, be healthy. So, we don't know how much it has actually impacted healthcare. We've actually found that people who get sequencing done, get genetic testing done, don't typically follow up with a lot of very expensive tests and procedures. Either one of two things is happening there. One is that the information that they're getting isn't telling them much that is actionable, something that they can actually do something about. The other possibility is that physicians are doing their job which is that they're sort of acting as the gatekeepers and saying: no, you'd actually clinically don't need that test or that's not indicated at this point in time. This is what we should be doing. We want that. We want it to target the right treatment to the right people. So, if you get genetic test results, we want you to follow up with the appropriate follow-up care, treatment, screening, or whatever you need. We don't want you to over treat because of some concern that that may be underlying and not relevant to you at the time.

Erin: Is there any evidence that people who take it home tests are making any changes in their lifestyle, their habits, as a result of what they learned about their health?

Dr. McGuire: There certainly are anecdotal cases out there. So I think Francis Collins one time got up and for a number large group and said I had my direct-to-consumer genetic testing done and I went you know I was motivated by the results to go on a diet and lose whatever 40 pounds or whatever. So people think: yeah that's great we should be doing more of that! We've actually done some research looking more systematically at how people are responding to genetic testing information, whether through a direct-to-consumer company or not. We have one study focused on that and other studies that are focused more on getting this information in a healthcare setting and the sad news is that it's really hard to change people's behaviors. We find that generally there might be a little spike in people eating a little better and doing a little more exercise for a couple months or a couple weeks, and then they go back to their regular behaviors. We hope that it would change people. We hope that anything would change people. We know that you don't to get a genetic test to know that you should eat well and you should exercise and you should take care of yourself. If you're not doing that, maybe this is the thing that puts you over the edge and motivates you to start that diet or to start doing your daily exercise. The evidence shows that it actually doesn't do that in a significant way for the majority of people over the long haul. So, we need to look at that and say how can we better motivate people to be engaging in these behaviors.

Erin: What about psychological effects of learning more than you bargained for?

Dr. McGuire: So the major concern that we've had is that people are going to get horribly depressed and anxious by getting this information. We've now had a series of studies that have looked at people's psychological response after getting genetic testing and uniformly they show that people don't get clinically depressed or anxious. We actually are very adaptable as a human species. We are really bad at predicting how we're going to feel about things. We really are. We will say: "oh my god I would feel horrible if I got this information." -- There's been tons of human psychology studies done on this -- "My life would be miserable I would never be happy again". But, we're extremely adaptable. So what we find is that most people who get this information, including what you might think of is particularly troubling information like increased risk of Alzheimer's disease for example, don't usually get clinically depressed or anxious. Now, the data on something like Huntington's disease might be slightly different. I don't know that data quite as well, but that's kind of a special case. For most of these other risk alleles that we're looking at, people don't get incredibly anxious or depressed.

But do they have others like me who might have more subtle psychological responses to this? Like the kind I was worried about with myself. Do they think differently about themselves? Do they treat themselves differently? We don't really know. We're doing a study right now looking at babies who are getting their genetic testing done, not in a direct-to-consumer setting but in a clinical setting, and we're looking at whether getting their genetic information impacts the way that their parents interact with them, how parents treat them, how parents interact with each other, those sorts of things. We're still sort of analyzing the data, but it looks like there actually is a little bit of an effect on how vulnerable you think your child is when you get risk information about them. So do you bring them to the doctor more often? Do you worry that they're going to get sick more often? Does that have an impact on them or on their psychological development long-term? I don't think we know that yet, and I think that's worth continuing to watch and to study and to be sensitive to.

It's complicated. If there was an easy answer or there was one issue I think we might have solved it but there's new things keep coming up. I think you know part of part of our challenge is to try to get ahead of the game and not to be alarmist about it. But, to try to think about where is the science going? Where is the industry going? A lot of the work that I do is really trying to bring together industry stakeholders, scientific stakeholders, consumer stakeholders, patient stakeholders, government stakeholders. Get everybody in the same room to talk about these things. I think one of the challenges is that you know I as a scientist don't know what you know the heads of these companies are thinking what their business model is, where they want to see this going in ten years and what they see as the major challenges. Similarly, they don't know where the science is going and what we might be capable of or what we see as the challenges. So, there's a lot of opportunity there for increased dialogue across disciplines.

Erin: What should people keep in mind before taking at home tests? What kinds of questions should they ask themselves before ordering an at-home genetic test?

Dr. McGuire: Before ordering at at-home genetic test, I think people need to think about: Do I want this information? What information might I get back? Do I really understand what this information is going to mean for me? Everyone hates to read the fine print right. None of us do it. Yet, I really think these companies have relied on their Terms of Service to lay out what are their privacy policies are, who's going to get access to your information, and how are they going to be able to use it. So people really need to read the Terms of Service because all the companies are different and their terms are different. You need to kind of go in eyes wide open and know what you're signing up for.


Erin: Thank you for tuning in to Body of Work by Baylor College of Medicine. If you enjoyed this episode, be sure to listen to part 2 of our interview with Dr. McGuire. It focuses on privacy and the use of genetic information in forensics.

If you like the show, please give us a five-star review and tell your friends to listen. We’re available on Spotify, Apple Podcast and Stitcher as well as at There you can also find the episode notes, including information about the experts featured on the show.

A quick note about the medical advice and opinions stated in this podcast: each individual’s health profile is unique, so please see a healthcare professional about any questions you may have.

Until next time, take care.


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