As many geneticists have pointed out repeatedly over the years, the cost of DNA sequencing is dropping at an exponential rate. Human genomic information will soon be utilized in the personalized medicine age. But for people willing to bank on one percent of their genome instead of all three billion base pairs, that age is already here.
In 2008, TIME magazine called the launch of direct-to-consumer (DTC) genetic testing company 23andMe the invention of the year. When it initially launched, it promised to predict your health risk for over a hundred complex traits, two dozen single gene disorders, a handful of pharmacogenetic profiles, and genetic ancestry using half a million markers for around $500. Today, 23andMe offers the same analysis for $99. And that appears to be the magic number. Thousands of people have since opted to have an Oragene kit shipped to their door, spit about one teaspoon of saliva into a purifier tube, mail it off, and wait two to six weeks for their genetic fortunes to be read.
While other DTC genetic testing companies may have come first, they have not been the most appealing. Noted one recent 23andMe participant, “When I look at other [DTC genetic testing] websites, it looks like they’re operating out of a basement.” Indeed, other genotyping companies with essentially the same technologies and services as 23andMe have pretty much ended up in the gutter. DECODE, the parent company of DTC genetic testing company DECODEme, went bankrupt last year, and another company, Pathway Genomics, was significantly curtailed when the FDA halted the planned sale of its DTC genetic tests at Walgreens nationwide. Part of 23andMe’s success in the DTC genetic testing arena can be attributed to their creative marketing campaign, their user-friendly website, accessible tutorials on genes and inheritance, and a little brand recognition and star power that went a long way (23andMe cofounder Anne Wojcicki is a Yale alum and the wife of Google founder Sergey Brin, and both Warren Buffet and Jimmy Buffet were enthusiastic 23andMe participants).
While other companies sought to define themselves as experts dispensing vital health information first and foremost, 23andMe simply advocated that DNA was fun, was something you had a right to know about, and perhaps most tantalizing in our social networking age, was something that you could share with others. And in an age of people with shrinking attention spans, they promised to deliver this shareable information relatively quickly. In an age where painfully inefficient bureaucracy awaits us at every turn, part of 23andMe’s appeal is the pace at which data is collected, analyzed, and shared. In a piece for Wired magazine last year, journalists asked an NIH official how long it would take the NIH genetics core to identify the genetic basis of a complex trait like Parkinson’s disease using 500,000 genetic markers and predict risk for disease. The answer was telling. What the NIH required six years to accomplish, 23andMe completed in eight months, and arrived at the same results.
Granted, some of the reported traits are of questionable use—who cares if you can smell asparagus metabolites in your pee?—and some of the predictions are downright wrong. I experienced this first-hand when one of my results informed me that I have curly hair (my hair is so pin-straight that even the cruelest of heating elements have failed to help it defy gravity). Thankfully this is a mistake regarding something trivial like hair texture, but if the site is providing inaccurate predictions about physical traits, how many of its health predictions for alcoholism, various cancers, and bipolar disorder, among others, are equally erroneous or at best, premature?
The risk for genetic misinformation at this early stage is quite high for a number of reasons: the discovery sample might be of an ancestry that differs from that of the participants; not all contributing loci are known; there could be unidentified gene-environment interactions, etc. Glossing over this fact gives people a false sense of confidence. Says one user of DTC genetic testing company Navigenics: "We hear a lot of different – and sometimes conflicting – opinions about how to take care of our health. I’m very excited about receiving only the most relevant information to me, based on my DNA." This is not an entirely accurate statement, however. While it is true that particular interventions such as certain diets or exercise routines might only be beneficial to a subset of people with a given set of genetic determinants, the risk predictions for diseases reported by these DTC genetic testing companies are still population-based, and conflicting genetic reports occur just as often as conflicting intervention reports. And unless those genetic risk predictions consider all known markers, the risk prediction you receive is very likely wrong. Take for example Francis Collins’ own experiences with DTC genetic testing. Collins, most famous for identifying the genetic cause of cystic fibrosis, for pioneering the human genome project, and most recently for heading the NIH, clandestinely submitted his own DNA for testing to three different DTC genetic testing companies. His predicted risk for prostate cancer varied dramatically from one test to the next, ranging from 23andMe’s “not at risk” to Navigenics’ “elevated risk of 40%.” How was this possible? While these three companies had roughly similar coverage of the genome, the coverage of known prostate cancer risk loci varied substantially among the providers, ranging from 3 SNPs in 23andMe’s test to 18 markers for Navigenics. Given that three similar products resulted in such discrepant predictions, it seems obvious that the release of these services for complex disease risk prediction was premature.
Daniel Goldhill, a third year in Yale’s EEB program, says he would only consider purchasing a 23andMe product for its carrier testing of single gene disorders, since “there are a lot of known disorders associated with Ashkenazi Jews.” He is less interested in the risk prediction for complex traits, however: “Why do I want to find out now if I’m at risk for some terrible condition when I’m fifty? Plus it depends how accurate [the prediction] is. Why look only at sequence data? What about gene expression? What about microRNAs? Epigenetics?” Laurel Hochstetler, a first year MCGD student and recent 23andMe participant, echoes that sentiment: results “should be taken with a grain of salt. They’re using such a small number of markers and supporting papers. There’s so much more to it...papers aren’t infallible, even if they are peer-reviewed”.
23andMe might insist that they are merely providing information with no intention of dispensing medical advice, but nevertheless, the majority of the information contained in their reports is genetic risk prediction for nearly one hundred complex diseases. As Richard Lifton once put it, this basically amounts to “practicing medicine without a license.” While there are many non-medical reasons for pursuing DTC genetic testing (adopted individuals who lack family history but are curious about their ancestry or want to find relatives, for example), there is a consistent theme of taking control of your health information. Despite calling it a “terrible idea”, Lifton conceded “what they’ve demonstrated is how many people are eager to do this.” Hochstetler agrees. “I just wanted to compare. Part of me loves to see all the combinations people have.” Despite have incomplete medical information, 23andMe has managed to get its foot in the DTC genetic testing door by catering to individuals’ curiosity, which will serve it well when it plans to use its swath of genetic data for its own participant-driven research endeavor, “23andWe.”
One interesting question will be how 23andMe will handle the shift from SNP genotyping arrays to whole-genome sequence data. Says one cell biology student, “I think it would lead to the world being like GATTACA, designing our own children. But if it takes more than 5 minutes, I’m not doing it. Maybe if I was bored on a rainy day or something.”
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