Genetics
Commercialized Genomics Caveat Emptor Steve Heilig, MPH My dog is a mutt—part Australian shepherd, maybe mixed with some kind of retriever, Bernese mountain dog, who knows. I don’t much care and he certainly doesn’t. I could learn about his genetic heritage; for years now, companies have been offering, for a fee, to examine any dog’s spit and tell you that, yes—that’s a dog. This has always struck me as a pointless exercise; again, he’s a mutt, as am I. On the human side, most anytime I turn on my computer these days, various ads from outfits (like, say, 23andMe) pop up and offer to help anybody “learn about your ancestry” and “better manage your health” and more—if I send in some of my spit and, of course, money. “Find out things like if your body metabolizes caffeine quickly, or if you’re at a higher risk for diabetes. The more you know about your DNA, the more you know about yourself” says their homepage—a tautological statement that begs the real question: What might one really do with the knowledge? Not to pick on 23andMe—they are just the most visible “personal genomics” company so far, but: A lot of knowledgeable people are of the opinion that such testing isn’t of much practical use. Make no mistake, genetics can be important and there are many cases, particularly in reproductive medicine, where knowing more about the genetic makeup of oneself can be helpful. The BRCA issue in breast cancer is one visible example, other authors in this edition of San Francisco Medicine detail other useful, targeted diagnostic and treatment options. There are also some fascinating “big data”-type efforts underway, including at UCSF and Kaiser, to tease out risks linked to genetics. At this point, though, such research is in the “potential/future” state with respect to workable new interventions. A few years ago, San Francisco writer David Ewing Duncan explored within his body, including his genes, to write a book titled Experimental Man: What One Man’s Body Reveals About His Future, Your Health, and Our Toxic World. In it he revealed much about both the promise and the limits of the kind of personalized testing increasingly being hawked online and elsewhere. Duncan donated his blood for testing to examine his genes, brain, and body to “humanize science by having a real person with a family and children intimately participate in leading-edge technologies.” He aimed to provide some insight into a coming “new era of medicine” wherein we might “acquire profound new powers of knowledge about ourselves, possibly more than we want to know.” Duncan lost his “genetic virginity” mostly so that scientists might tell him of his probability of developing various diseases. He had far more testing than any of the “personal genetics” companies offer. In a blog post subsequent to his book, he warned that “Scientists don’t yet know what all our DNA does—how each difference in genetic code might influence disease or the www.sfms.org
color of your hair. Nor have studies confirmed that all the genetic markers linked to, say, heart disease and most cancers actually increase a person’s risk for these illnesses. Just as significant, the thousands of genomes being cranked out right now can’t easily be compared. There is no standard format for storing DNA data and no consistent way to analyze or present it.” Thus he received often-conflicting interpretations of his test results from various experts. Almost without exception, physicians he consults about his “DNA tower of Babel” use terms like “tentative” or even “irrelevant.” They do offer well-established advice we should already know—exercise more, don’t be overweight, don’t smoke, drink alcohol moderately, eat healthily, beware of high blood pressure, and so on. You don’t need any genetic tests to know these are good ideas, or to start practicing them. But these proven “interventions” don’t profit technology companies. A Harvard geneticist in Duncan’s book calls the new genetic testing “technology hucksterism.” But even if these tests become truly predictive, Duncan asks, “Who will have the time to analyze the data and to indulge the healthy in possible scenarios of future illness?” That’s a good question, and for the near future, the answer is still likely something like, “Mostly relatively affluent, gullible, perhaps even narcissistic hypochondriacs—and health insurers looking for new ways to exclude ‘risky’ patients.” This is a new example of the “technological imperative”—because something can be done, it should be done—and as we are learning all the time, that is not always a good thing in medicine, for multiple reasons. In the trenches, clinicians are increasingly besieged by the “worried well,” who bring all manner of marginally relevant information into exam rooms—at the “opportunity cost” of using valuable time addressing real health issues one might do something about. Policies are being put into place requiring that such tests, to be useful and covered, must be ordered by genetic counselors and knowledgeable physicians. Thus, for the foreseeable future, the wisest approach to these experimental tests might be nothing new, and of an entirely nontechnological type: Let the buyer beware. Steve Heilig, MPH, works on public health issues at the SFMS. He is also editor of the Cambridge Quarterly of Health Care Ethics. November 2013 San Francisco Medicine
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