How to Navigate Imprecision in the Precision Medicine Era
When it comes to genetics and what we can learn from it, the progress we’ve made can make your head spin. I became interested in a genetic counseling career in the late ‘90s, which feels like ancient history. Back then, I’d speak to families about the possibility of a genetic condition, but there likely wasn’t a genetic test available to tell us more. If we confirmed a diagnosis, there usually weren’t many treatments to help. We’ve come a long way.
The Human Genome Project wrapped in 2003, which National DNA Day commemorates every year. Thanks to this massive international collaboration, scientists now know the entire DNA sequence of our genome. In other words, they know all the genes that make us who we are. We’re talking about 30 billion bits of DNA!
How did that help? It paved the way for scientists and researchers to better understand genetic variants – the genetic differences between us – and how some of them might cause health problems. If we know how a disease happens, we can better figure out what treatments can help or prevent it.
Enter, precision medicine. It’s a fancy term that simply means using someone’s genetic makeup to more precisely diagnose or treat a medical problem, whether an existing problem or one a person is at risk of having in the future. Precision medicine aims to shorten the long, winding road that many have had to take to reach a diagnosis. Precision medicine, specifically pharmacogenomics, aims to avoid the trial-and-error that often comes with figuring out the ideal medication or dose for a health problem.
Sounds great, right? It is, but precision doesn’t mean 100% precise. As a genetic counselor who has met many families over my 20+ years in the field, there’s one thing I still say – we know a lot about genetics, but there’s still a lot we don’t know.
Many people are surprised to hear this, especially from a medical professional. Doesn’t science have all this stuff figured out, especially since all it takes to explore our genes is spitting into a cup and sending it off for at-home genetic testing? This topic even came up in an episode of the “Genetic Counselors & You” podcast I did with fellow genetic counselor, Scott Weissman. We understand why you’re surprised. If you watch TV, listen to podcasts, or scroll through your newsfeed, you’re likely hearing that DNA testing is the cutting-edge way to learn more about yourself. It is, but not to the extent the advertising or mainstream media might have you believe.
Bottom line: A lack of precision is OK.
Why? Because there are resources available to help – genetic counselors have special training to help you navigate uncertainty as you learn about your genetics.
Here are some common ways that uncertainty can arise when you learn about your genetics:
- We know how many – but not all – our genes work.
Example: You get a DNA test result showing that you have a variant in a gene linked to colon cancer, but we don’t know how close that link is. This means we don’t know exactly how high your colon cancer risk is, based on your genetic test alone.
- We don’t understand the impact of all the variants genetic tests can find.
Example: You get a DNA test result showing that you have a genetic variant known as a “variant of unknown significance” or “VUS” result. This means we don’t know if this genetic variant is harmless or if it could impact your health, based on current scientific knowledge.
- Pharmacogenomic testing has promise, but isn’t mainstream yet.
Example: You want to know if a medication will work for you based on your genetic makeup and you turn to pharmacogenomic testing. Pharmacogenomic testing is currently limited to a small number of medications and health issues, and may not apply to your situation.
- Genetics isn’t the complete answer; other factors impact your health.
Example: You get a DNA test result showing you have an increased risk for high cholesterol. Your activity level, diet, biological sex, ethnicity, other health issues, and environment all play into your overall risk for high cholesterol.
- Genetics usually tells you about a high or low health risk – but risk is not certainty.
Example: You get a DNA test showing you have a lower risk for a blood clotting problem than the average person. While this is reassuring, it’s not a guarantee that you won’t get a blood clot.
How can a genetic counselor support you during these types of uncertainties?
- A genetic counselor can help you understand limits in scientific knowledge that impact your DNA test result and offer ways for you to move forward with your health, even with this uncertainty.
- If you get a VUS test result, advances in the science could clarify its meaning sometime in the future. A genetic counselor can stay on top of the latest information and can be your source for updates that might impact your health.
- If you’re interested in pharmacogenomic testing, a genetic counselor can look at your entire health story to figure out if this testing could help, and if it can, help you consider the right test and understand your results.
- A genetic counselor can consider all the important factors, such as your family history, to offer you next steps after you get your DNA test results. Addressing the whole picture can help you avoid a false sense of security or fear based on your test results.
Exploring your genetics can be exciting, but also challenging if you’re not comfortable with unknowns. Having someone to turn to who can offer support and realistic hope can make a positive difference. Genetic counselors are used to working in a field that’s always evolving, expanding, and reinventing itself – in part, it’s why many of us entered the field. It’s our job to partner with you to be a steadying anchor to help you avoid motion sickness as you adapt to your genetics discovery.
Genetic counselors are available in person at many medical centers or clinics, over the phone, or by secure video chats depending on where you live. If you’re in the U.S. or Canada, you can search for a genetic counselor near you by clicking here.
Interested in a genetic counseling career? Click here to learn more about the field.
Deepti Babu, MS, CGC, is a 2018-2020 Director at Large with the National Society of Genetic Counselors. She brings her experience as a genetic counselor into her work as a consulting medical writer and editor, always trying to bring realistic hope to whatever she does.
Twitter: @Deeptiwriting https://twitter.com/deeptiwriting?lang=en