We’ve been talking a lot lately at Medcan about whole-genome sequencing. So much so that I decided I need to experience it for myself. To do that, I went to San Diego’s Human Nucleus future-medicine facility, founded by the maverick genetic pioneer Craig Venter.
Before I explain what the experience was like, let me first explain the difference between most of the consumer-level genetic analysis happening today, and whole genome sequencing.
The human genome comprises about 20,000 genes and three billion letters of information. The limits of computing power, the finite nature of our scientific knowledge, and the expense of the technology, has made it impractical to examine every last one of those letters. So in the interests of efficiency, most current genetic screening concentrates on analyzing a subset of genes that we believe are significant. For example, Medcan’s own proactive genetic screening looks at 147 genes that are likely to impact human health.
That said, the amount we know about the human genome is increasing all the time. Plus, the cost of sequencing is falling rapidly. Sequencing the first genome is estimated to have cost $3 billion at the dawn of the millennium. Nearly 20 years later, a commercial enterprise can do it for a cost of several thousand dollars.
Medcan’s director of genetics, Allison Hazell, believes whole-genome sequencing has benefits. Because the information in the genome stays constant through one’s life you only have to do it once. “Sequence once, interpret often,” Hazell says.
Think of getting your genome sequenced a little like building a library devoted to your own personal genetic health information. Once you build it, you can visit the library whenever it makes sense to check in. Your parents could examine it soon after your birth, to check whether you have any genetic disorders. If you need to be prescribed medicine, you could perform a pharmacogenomic analysis to learn about how your body interacts with drugs. You could consult with it when you’re thinking of having children, to minimize the chance that you and your partner might pass on a genetic disease. I’d also recommend peering into the genes currently available on our proactive genetic screening to learn about your tendency to develop cancer, cardiovascular disease, or other medical problems.
The information would then be used to guide your medical care on an ongoing basis. So if you have elevated risk for a certain type of cancer, you would be more likely to undergo earlier, and more frequent screening. If you’re more likely to develop heart disease, you may want to start cholesterol screening in your 20s, and be more disciplined in terms of your cholesterol intake and the frequency that you engage in physical activity.
“One of the things we’re always thinking about is how to provide people with responsible information about their genome,” Hazell says.
When I visited Human Nucleus earlier this spring, the genome analysis part of my visit involved providing a blood sample. I received my results about a month later. Even though I’ve had several genetic screenings performed through the years, getting my entire genome sequenced told me new things about myself. For example:
As a result of my experiences in San Diego, I’ve decided that Medcan clients would be well-served to be able to choose to get whole-genome sequencing as part of their annual health assessments. Medcan has Canada’s best private team of genetic counsellors, who work with clients to provide context and information about test results. Providing our team with a tool like whole-genome sequencing could do a lot of good. So over the next few months, the company will be seeking a partner to provide that service. Stay tuned.