Ep. 109: Whole Genome Sequencing & Precision Medicine
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The ultimate way to personalize health and wellness strategies is to use one’s unique genetic code—to have every one of your DNA’s base pairs mapped, in a process known as whole genome sequencing, and then using that information to create precisely the right strategy for you. With its Genomic Health Assessment pairing whole genome sequencing with a host of innovative wellness screening measures, Medcan is empowering clients with the most complete picture of their current and future health. In this episode, Director of Clinical Innovation Allison Hazell (above, right) is interviewed by our host, Medcan CEO and Chair Shaun Francis (above, left), about the past, present and future of genomics, and the field’s precision wellness implications.
LINKS
Learn more about Medcan’s Genomic Health Assessment.
Medcan Genetics: To arrange a conversation with someone from Medcan about whether you’re an appropriate fit for the Genomic Health Assessment, including whole genome sequencing, click here or email genetics@medcan.com.
Personal Genome Project Canada 2018 research study write up in the Canadian Medical Association Journal.
Learn more about the Personal Genome Project Canada at its webpage.
The episode references the Siddhartha Mukherjee book, The Gene: An Intimate History.
Allison Hazell discussed the development of the Genomic Health Assessment in an article.
Scientists sequenced the first complete human genome in 2003. Here’s a timeline of major advances in genetics.
INSIGHTS
The first complete human genome was sequenced in 2003. It took about 10 years and cost millions of dollars. Since then, many more genomes have been sequenced under the auspices of research programs, such as the Personal Genome Project Canada, that aim to improve our ability to interpret genomic data—to help us understand the difference between benign genetic variants and mutations that actually will have a big impact on one’s overall health risk. Thanks to research and increased uptake of genomic sequencing, we now have a good idea of the purpose of approximately 5,000 genes of the approximately 20,000 that comprise the human genome. “What was found,” says Hazell, “is [that] about 25% of people had some type of health risk that would impact their health in some way. And every single participant had information that could be used, if not for themselves, [then] for their offspring.” [3:55, 17:11]
More about the Personal Genome Project Canada: That’s a large-scale research study started in 2010 to perform whole genome sequencing on healthy individuals, to determine how to use genetic data to optimize health. Medcan has donated genetic counselling in kind to the project since the beginning. The counselling process involves meeting with research participants to review their whole genome sequences. Hazell and her team’s involvement with that project shaped how they designed Medcan’s whole genome sequencing program. For example, the PGP Canada report lists every genetic variant identified, regardless of whether that variant has been proven to benign or is still in a grey area where we aren’t sure whether it is relevant to health risk, or not.. “You get a lot of noise and data that may not be useful,” Hazell says. “So at Medcan, one of the things that that we've chosen to do is give people only the information that is well known, well validated .” [13:15]
Shaun asks for examples of the way genetic testing has caused someone to change their behaviour. “We've had a number of cases where we've identified a risk that's changed somebody's medical management significantly,” says Hazell. For example, one client learned that they're at a much higher risk for ovarian cancer. In that case, the client was already in menopause, meaning their reproductive years had concluded, so they chose to have their ovaries removed as a way of actively preventing that cancer risk. Another example Hazell describes involves cases where genetic testing has revealed substantially elevated risk for developing cardiovascular disease. “And so we were really able to change the course of that person's life, in terms of giving this information upfront, so that they can use it productively.” [18:16]
One person who has had his whole genome sequenced is Shaun. He learned that he is a carrier for muscular dystrophy, which could affect the reproductive choices of his three sons (none of whom have the condition). He also learned from the sequencing that he is an ultra-rapid metabolizer of codeine, a common pain medication. That’s important because codeine dosages are based on people who metabolize the drug normally. “If we know that you're in the 5% of people who metabolize codeine more quickly,” Hazell notes, “we can say, okay… the regular dosing guidelines don't apply to you... And if you are just given the standard dose, you may be at risk for a side effect down the road.” The field of using genetic data to learn about the way individuals metabolize certain drugs is called pharmacogenomics, and it can be particularly important when MDs determine dosing or medication choice for mental health medications designed to treat anxiety and depression. [22:10]
One benefit of whole genome sequencing is that once you do it, you’ll have the data on file indefinitely, to be consulted when you need it. “The idea with whole genome sequencing,” says Hazell, “is that you're sequencing once and then interpreting and using it often in different scenarios based on context and need.” The information can also be used in the future to provide additional insights as new scientific discoveries are made and we learn more about the implications of additional parts of the genome. [26:00]
Shaun asks, “Should someone be worried about how this might impact their ability to get insurance at a later point, be it health insurance or life insurance?” No, says Hazell. “In 2017, the federal government passed the Genetic Non-Discrimination Act, which is a federal law that prohibits insurers or employers from using genetic information in a discriminatory way.” So in Canada,, genetic test results from whole genome sequencing or other genetic testing cannot be used by insurers to increase your premiums or deny you coverage. “This is really important because we've had countless conversations with people who are interested in getting this information, and want to be proactive about their health, but choose not to do it because of fear of having their premiums go up, for example… And so the Genetic Non-Discrimination Act has removed that issue.” [27:30]
“What does genome sequencing mean for the future of [precision] medicine?” asks Shaun. “It will influence everything from your annual screenings and your primary day-to-day care, what medications are prescribed to you, what type of diet you follow,” says Hazell. “It's the foundation that everything else will build upon.” [28:35]