Before one of her pregnancies, my wife took a genetic test to find out if she was a cystic fibrosis carrier. Her doctor ordered the test, and other than the bare result — negative — she was given no information. She was told nothing about the genetic variants that were tested for, and nothing about the small but real chance the result was wrong. (Fortunately for us, the test wasn’t wrong — our children are fine.) For my wife, the cystic fibrosis carrier test was just one more routine but obscure medical test used by her physician to make an expert medical judgment. It was not something for us to concern ourselves with.
When you compare my wife’s fairly standard experience against the cystic fibrosis carrier test offered by consumer genetics company 23andMe, there is no contest: 23andMe leaves its customers much better informed. When you get the results of your 23andMe test (which you can order for yourself, without a doctor), an accompanying report explains how the test works and what its limitations are. If your test result is negative, as it is for most people, you’re told that “you could still have a variant not covered by this test.” You’re also informed about how your ethnicity might affect the accuracy and relevance of the results. 23andMe’s cystic fibrosis carrier test looks for mutations that most often cause cystic fibrosis in people with European, Latino, or Ashkenazi Jewish ancestry. If you are African American, you’re less likely to be a cystic fibrosis carrier, but you might also have an undiscovered mutation not covered by the test.
Those who are curious can follow a link to an explanation of the scientific details behind the test, including the exact mutations that 23andMe examines, with references to the relevant studies. Another link in your online report takes you to a simple tutorial that clearly describes what it means to be a carrier of a genetic disease. And, importantly, the report emphasizes that a genetic test by itself isn’t always definitive — if cystic fibrosis runs in your family, you should talk to your doctor, even if your 23andMe test is negative.
Few people carry mutations for cystic fibrosis or other rare diseases, but thanks to a major decision this month by the Food and Drug Administration, 23andMe will soon offer genetic tests for more common diseases, like Parkinson’s, Alzheimer’s, and celiac disease. Reports on these diseases used to be part of 23andMe’s genetic testing service, but in 2013 the FDA ordered the company to stop issuing the reports. The FDA had decided that consumer-grade genetic tests counted as medical devices that “could have significant unreasonable risk of illness, injury, or death,” and therefore had to be approved by the FDA. A test user might, for example, misinterpret a result and alter the dose of a prescription drug without consulting their doctor first.
Two years later, after going through an approval process with the FDA, 23andMe came back with a stripped-down version of its testing service that reported on a very limited set of diseases — the carrier tests for rare diseases like cystic fibrosis, which are not especially relevant or interesting to the vast majority of the company’s customers. It wasn’t clear whether 23andMe would ever again be able to offer consumer genetic tests for common diseases.
But the company now has a green light from the FDA. On April 6th, the FDA announced it has classified consumer genetic tests as “low-to-moderate risk” medical devices, and established a streamlined approval process that will allow 23andMe to rapidly add more disease-related tests to its service. This is big news, because the FDA has finally taken a clear stance on the decade-long debate over the legitimacy of consumer genetic tests: Should you be able to freely access your own genetic information, without a doctor’s permission, or is it too risky to let people wade through such complex, easily misinterpreted information on their own? The FDA has decisively come down on the side of free access.
The agency has decided to categorize consumer genetic tests like 23andMe’s as a new type of medical device, called a “Genetic Health Risk Assessment System.” As far as risk goes, the FDA considers consumer genetic tests to be “Class II” devices, meaning that they’re about as risky as condoms (another Class II device)— that is, riskier than dental floss (Class I), but not as dangerous as a faulty pacemaker (Class III). To mitigate the potential risks of a false or misunderstood genetic test result, 23andMe had to demonstrate that its technology and analysis methods are accurate, and that its reports effectively convey both the results and the limits of the genetic tests to users. 23andMe revised its test reports, and conducted a user comprehension study. The study, the FDA noted, showed that users understood “more than 90 percent” of the information in the test reports.
Another likely factor in the FDA’s decision, though the agency didn’t reference it specifically, is the growing evidence that letting people buy genetic tests on their own isn’t that risky. Forbes reported that, to obtain FDA approval, 23andMe conducted a study of 25,000 test users in the United Kingdom (where the company has always been allowed to sell disease-related tests), and found no incidents of harm. This is in line with the results of several large, ongoing public studies, which have also reported little or no risk to people who take consumer genetic tests.
Not everyone is happy with the FDA’s decision. On the day of the FDA’s announcement, I saw some of my colleagues take to Twitter with terms like “snake oil” and “fraud.” Many in medicine are still hostile to the idea of letting people buy genetic tests directly, without the guidance of a physician or genetic counselor. Their concerns have some merit. In most cases, a genetic test by itself can’t give you an accurate picture of your overall risk for developing Alzheimer’s or celiac disease; you typically have to consider your family history, lifestyle, and current state of health as well. Critics argue that, given their limits, consumer genetic tests aren’t much different from weight loss pills or herbal remedies, sold with the promise of health benefits that have no backing in science.
But this perspective is quickly becoming untenable. The information is coming, and the medical profession can’t realistically keep people from learning about their own DNA. The effort to find links between our health and our genes is now one of the major thrusts of biomedical science, and the science gets better every year. Fueling the progress in science is the rapid pace of innovation in genetic analysis technology. Soon, the kind of one-off genetic test that my wife took more than a decade ago won’t make any sense; more comprehensive tests of the kind that 23andMe provides will be more cost-effective, and they will become routine.
As that happens, we’ll need to figure out how to help people make sense of their genetic information, and what it says about their risk for dozens or even hundreds of diseases. Busy doctor’s offices are almost certainly not going to lead the way here. The real innovation is going to come from consumer genetics companies that have the financial — and regulatory — incentives to help us to engage with our own genetics.