To be sure, the FDA does warn users of the HIV test that it is “important never to use a negative test result to decide on whether to engage in behavior that puts you at risk for HIV infection.” In a similar manner, 23andMe carefully explains to its customers, “No matter what your ethnicity or ancestry, it is important to understand that the absence of these mutations does not rule out the possibility that a person may have another genetic variation that increases the risk of these diseases.”
The good news is that a 2013 peer-reviewed study by 23andMe researchers of how customers reacted to their BRCA results found that those who tested negative “did not report inappropriate actions, such as foregoing cancer screening.” The study also noted that “all but one of the 32 mutation-positive participants appreciated learning their BRCA mutation status.” In addition, the researchers who conducted a 2009 Genetics in Medicine study that analyzed how patients responded to the results of a suite of eight genetic risk susceptibility tests reported, “We found no evidence that those who considered or sought testing were inclined to overestimate the contributions of genetics to common health conditions or to underestimate behavioral risk factors.”
The FDA also sketches out a scenario in which 23andMe customers would use their warfarin sensitivity results to “self-manage their treatments through dose changes” producing dangerous blood clots or bleeding incidents. As it happens, my 23andMe results indicate that I have increased sensitivity to the blood-thinning drug. Fortunately, I don’t have to use it right now, but I certainly would let my physician know these results in the event that I needed such a treatment.
23andMe tests for the same variants relevant to warfarin sensitivity that the test approved by the FDA does. By the way, stand-alone warfarin sensitivity tests cost between $200 to $400. In any event, I seriously doubt that 23andMe customers who aren’t using warfarin will all of a sudden start anti-coagulant therapy for the fun of it. Nor will those currently on warfarin stop listening to their doctors and begin to self-treat by swallowing d-CON pellets. Furthermore, 23andMe advises at the top of the webpage reporting my warfarin results, “Only a medical professional can determine whether warfarin is the right medication for a particular patient. The information contained in this report should not be used to independently establish a warfarin regimen, or abolish or adjust an existing course of treatment.”
So far, nearly 500,000 people have purchased 23andMe’s Personal Genome Service. Interestingly, the FDA’s warning letter does not mention that the agency has received any substantial customer complaints about the service. Anecdotally, I have recommended 23andMe to many friends and colleagues and have not heard any serious complaints about what they purchased or the information they received.
I have explained elsewhere that the development of all new technologies involve a societal learning process in which some early adopters try it out, explain to others how it works, and find out its flaws—which newer innovators then fix. The way the genetic testing industry will evolve is that the companies that tease out and explain useful information about disease risks and pharmaceutical interactions will be the ones to succeed. Despite the FDA’s parade of horrible hypotheticals, the bigger risk is that increased federal regulation will slow down the progress of beneficial genetic testing and treatment innovations.
Finally, New York University law professor Richard Epstein is right when he argues, “The FDA should have to show by clear and convincing evidence that 23andMe leads to the dangerous results that the FDA claims by surveying customers of the firm.” Until then, the agency should leave 23andMe and its customers alone.
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