In 2008, Time magazine named retail DNA testing the invention of the year. A scant two years later it is questionable whether this exciting new industry will survive heavy-handed regulation by the U.S. Food and Drug Administration (FDA). In June, the FDA sent letters [PDF] to the leading direct to consumer (DTC) genetic testing companies asserting the agency's authority to require "premarket review" of their tests in order to "protect the public from medical products that may pose an unreasonable risk of harm." So what are the "unreasonable risks" posed by the DTC tests?
Unlike X-rays or pharmaceuticals, there are no direct physical risks. The tests consist of spitting into a vial, mailing it in, and getting back a bunch of information about your genes a few weeks later. The risks allegedly posed by DTC genetic testing most commonly mentioned by those anxious to regulate the new industry are (1) consumers might make bad decisions based on test results, (2) consumers might suffer anxiety over test results, and (3) insurance companies might use results to increase premiums. Let's take each in turn focusing on studies that report consumer reactions to test results that indicate that they are at a higher risk for Alzheimer's disease.
Few maladies are regarded with more horror than Alzheimer's disease. Yet studies show that people who get test results suggesting that they are at greater risk don't do anything terribly dangerous in reaction to it, nor are they devastated by the news. If consumers of genetic testing can handle this type of information, it's hard to imagine what other genetic information well-meaning government bureaucrats should shield them from.
A 2008 study reported that 40 percent of participants with genetic test results indicating increased risk of Alzheimer's disease reported upping their use of medications or vitamins. The participants had been informed that no known interventions prevent or delay the onset of Alzheimer's disease. Oddly, the study did not differentiate between vitamins and medications. Presumably physicians wouldn't prescribe new medications based on these results, so it is therefore likely any medication changes involved over-the-counter products like aspirin.
The bioethicists must then be speculating that taking vitamins or medications aiming to reduce the risk of Alzheimer's could have deleterious effects. So how much risk would changes in vitamin or over the counter medication regimens among people at risk of Alzheimer's give rise to? More than 40 percent of Americans take vitamins and we swallow more than 20 billion acetaminophen tablets and more than 15 billion aspirin tablets each year. The most recent annual report of the American Association of Poison Control Centers [PDF] notes that not a single person died from taking vitamins. The same report also notes that 54 people died from taking acetaminophen and 16 from taking aspirin. Let's crudely assume that everyone of the one in four Americans—some 75 million people—who carry at least one copy of the APOE4 allele that increases Alzheimer's risk—starts taking vitamins or over the counter analgesics. That would imply that 18 additional people would die from changing their medications, yielding an increased death rate of more than 1 in 12 million. By comparison, about 34,000 Americans died in motor vehicle accidents, yielding a death rate of about 1 in 9,000.
Another recent study looked at how people react psychologically to finding out that they are at a higher risk of Alzheimer's disease. The researchers gave tests looking for the APOE4 allele which confers a considerably higher risk of Alzheimer's disease to 162 asymptomatic adult volunteers who each had a parent with Alzheimer's disease. The study found that those at higher risk were only transiently distressed and concluded, "The disclosure of APOE genotyping results to adult children of patients with Alzheimer's disease did not result in significant short-term psychological risks."
Under the Genetic Information Non-Discrimination Act, health insurers may not take genetic testing results into account when setting premiums. But with regard to long term insurance the situation is different. A 2005 study reported that people who tested positive for the APOE4 allele were nearly six times more likely to buy long term care insurance after testing. A new study suggests that this may be wise since people bearing this allele are about 50 percent more likely to enter a nursing home than people with alleles conferring average Alzheimer's disease risk. Currently, the vast majority of consumers and all long-term insurance companies do not have nor do they use this information in making insurance decisions. People who want to restrict access to this kind of testing are, in effect, arguing that genetic ignorance is bliss for both consumers and insurance companies. Is forced ignorance really the best policy?
Would-be regulators also worry that the genetic tests may not be analytically valid, clinically valid, or offer clinical utility. Analytic validity essentially means that each test would find the same data each time it's given and that the results would be consistent among tests. Evidence shows that for four of the leading genetic testing companies their results are analytically valid. All four report test results that are certified accurate under the Clinical Laboratory Improvement Amendments.
Clinical validity means that the test results correlate with the increased or decreased risk of specific diseases in a test-taker. Clinical utility means that the test can guide consumers to make decisions that improve their health. With regard to clinical validity, the DTC companies offer weakly predictive genetic susceptibility tests of common complex diseases like atherosclerosis, diabetes, and some cancers. For the most part, the current clinical utility of the tests resides in suggesting that consumers lose weight and exercise more. But that's not nothing. A 2009 study surveying interest in personal genome testing found that 78 percent of respondents said they would modify their lifestyles by dieting and exercising more if their genetic test results indicated a higher risk of cardiovascular disease. The main point to keep in mind here is that allowing consumers to use and purveyors to sell such tests will greatly speed up the process of improving both their clinical validity and utility.
In the current issue of Genetics in Medicine, Caroline Wright and her co-authors from the U.K.-based PHG Foundation, largely reject proposals for premarket approval [subscription required] of DTC testing by regulatory agencies. Instead they make five sensible recommendations that the FDA should heed as it contemplates regulating DTC genetic testing. The first is the "provision of transparent and evidence-based information through publically available registries." For example, the Genetic Testing Registry will be launched next year by the National Institutes of Health. Such registries will enable consumers and physicians to identify the providers that offer the strongest evidentiary base for their tests. Their second is that the tests should be accredited as analytically valid. As noted above, the leading DTC companies in the U.S. already do this.
The third recommendation is that statutory regulations be adopted to ensure the scientific validity of clinical claims being made by the testing companies. I do not believe that further regulations are needed since testing companies are already eager to demonstrate to consumers the scientific validity of their research. For example, both 23andMe and Pathway Genomics set out the criteria by which they include studies when they report results. In fact, 23andMe generally lists links to the studies on which the company is relying right beside the results it reports to consumers. In addition, testing companies are voluntarily moving toward using the Venice criteria which assigns letter grades to the quality of the genetic association evidence, its replication, and lack of bias. For example, a grade of AAA indicates strong evidence for a genetic association while a single C indicates weak evidence. I am inclined to agree that without this information, "it may not be an overstatement to regard the service as fraudulent."
The fourth recommendation is that all test providers ensure that consumers have access to people properly trained to interpret test results and offer advice. All four leading American genetic testing companies offer in-house or have arranged for outside genetic counseling to be available for their customers. And the final recommendation is that consumer protection agencies like the Federal Trade Commission should enforce their current regulations "to prevent misleading claims" and "unsubstantiated and overhyped assertions" by DTC genetic testing companies.
The FDA is being misled by some bioethicists who continue to believe that they can foresee how people will react to new technologies (always negatively) and professional organizations who want to stamp out their competition. If it turns out that down the road some genetic test results in some kind of real harm, that will be the time to start regulating it.
Disclosure: I am a happy customer of two direct to consumer genetic testing companies, 23andMe and Pathway Genomics.
Ronald Bailey is Reason's science correspondent. His book Liberation Biology: The Scientific and Moral Case for the Biotech Revolution is now available from Prometheus Books.