In genetic counseling, board certified professional counselors help people learn about genetic conditions. In the past, genetic counselors primarily worked in clinical settings, seeing patients and taking care of people in prenatal settings related to pregnancy and in pediatric settings where children are born with suspected genetic disorders.
More recently, genetic counselors have expanded their focus to include helping people affected by hereditary cancers and adult-onset genetic diseases. They have also moved into industry in a variety of roles that apply clinical knowledge to the development and commercialization of genetic services. As next-generation sequencing evolves, so too does the field of genetic counseling.
Illumina Staff Genetic Counselor, Erica Ramos, discusses the burgeoning field and clarifies some long-standing misconceptions related to genetic counseling.
Q: What would you say are some of the biggest misconceptions that you deal with as a genetic counselor?
There can be a misconception that screening is the same as a diagnostic test. Many people think that if a screening test is abnormal, there is a problem. Even with diagnostic testing, people can make assumptions that if we test for one condition, we're really testing for everything. That can get particularly complicated when we start moving into the world of whole genome sequencing. Since we are looking at so much of the DNA sequence, there can be an assumption that if something is wrong we're going to find it. Even though we're looking at a lot of that information, our knowledge about how every gene or every part of the genome contributes to human disease is still limited. But, we can get much further than we did before.
We also talk a lot now about diagnostic yields in the range of 30 to 50 percent. This means if somebody is suspected to have a genetic disorder, if we do whole genome sequencing, about 30 to 50 percent of the time, we're able to make a diagnosis. A lot of people think, if you're doing whole genome sequencing, the rates should be much better. The reality is that when we were doing testing before genome sequencing, we were maybe closer to 10 or 15 percent diagnostic yield. Thus, we have moved the needle dramatically into making better diagnoses and to making more diagnoses. It's just that we're still going to be limited as we learn more about how the genome predisposes us to risk for disease.
Along those lines, I think when we look at the genomes of healthy people, the expectation or the concern sometimes is that we're going to be able to see everything that's ever going to happen to them. We won’t be able to predict when they'll get diseases, if they get them. The reality is, as we sequence more healthy people, we're also learning that a lot of the very typical diseases that we thought we understood, we may not actually understand as well as we thought.
Q: Where do you see the field in five years, or where would you like to see it?
It's a really interesting conversation right now because there are only about 3,200 genetic counselors in the U.S. and Canada. We're a fairly small group, although we're growing pretty dramatically. In the past, genetic counselors really focused on being the primary care provider for delivery of genetic services. As genetic testing grows tremendously, as there are more and more people that need this genetic testing, we can't really quite do that anymore.
The direction that I'd like to see the field move toward and fortunately, it looks like it’s doing so, is really more around making sure people have access to the best genetic services. If that is a matter of genetic counselors training other people to deliver those services or aiding in the education of physicians, nurse practitioners, physician's assistants, and others that can provide some of those services, that's a really great position for us to be in. Ultimately, we need to make sure the information distributed to patients and to providers is accurate, complete, informative and easy to understand. Also, working with companies and helping to develop responsible genetic tests and appropriate genetic tests is an important role.
All of these opportunities are allowing genetic counselors to have a much broader impact than we may have been able to have when we were seeing one patient at a time. I think that's really one of the areas we're focusing on, how we can make sure that the most people are getting the best services, rather than necessarily trying to provide all of those services ourselves.
Q: Is there an overall takeaway that you’d like readers to gather from this conversation?
Going back to a topic we previously covered, it’s important as a genetic counselor to emphasize that although we've made huge advances in our sequencing technology and in our understanding of the genome, we are in the fairly early stages. Specifically, if we test someone with an undiagnosed genetic disease and don't find the problem now, it doesn’t mean that we’ll never find it. If we test somebody right now, as our knowledge of genomics is still developing, so we just may not know what we're looking for quite yet.
Over time, I think we're going to continue to get better, and what we have to make sure we reinforce in the clinical setting and when we're talking with patients is that we are at the beginning. This statement is particularly true in healthy adults, but we are also making a lot of progress. The more people we sequence and the more genomes we look at and the more people who share that information, the better we're going to get at making these diagnoses and knowing how to apply genomics to healthcare.
A highly prominent geneticist in the field, Howard Jacob, Ph.D., always says that the answer to all these things that we don't know is to sequence more people. That's what we need to keep doing. Keep looking for more people. Keep looking at more genomes. Keep moving the science forward. We just have to make sure that we're setting realistic expectations for what we can do right now, versus what we might be able to do in the next five or 10 years.