One woman panicked when the genetic test she ordered over the Internet concluded that her son was carrying a life-threatening disorder and, even more disturbingly, that he was not — genetically — her son. Another, who always thought she was white, was flabbergasted to find her genes were mostly of African origin. A third woman's result was still more stunning: She was a man, it said.
"I thought, 'Oh my god. Am I really a man?'" said Denise Weinrich, 48, of St. Peters, Mo. "I thought: 'What's the matter with me? I'm not who I thought I was. How am I going to tell my children?' DNA doesn't lie."
DNA does not lie, but its truth is often elusive. Weinrich was one of 87 people who received incorrect results last month because of a laboratory mix-up involving customers of 23andMe, a testing company backed in part by Google. The testing company from Mountain View, Calif., says it regrets the incident and noted that it spotted the mistakes quickly, notified the clients and has taken steps to prevent future errors.
But the blunder has fueled a debate over whether the government should more aggressively police the tests. Critics say that too many make claims that go far beyond the science, yield results too complicated for people to interpret on their own or are just plain wrong. But others fear more federal oversight will make the tests too expensive and hard to get.
"If you have things completely unregulated, then you have a Wild West of commercial interests around medical information," said Robert Green, director of Boston University's Center for Translational Genomics and Health Outcomes. "If you over-regulate, you run the risk of stifling innovation in a very dynamic industry."
Dozens of companies offer genetic tests that claim to tell people everything from what foods they should eat to live longer and what cosmetics they should use to whether they are at risk for cancer, Alzheimer's and other ailments, and how some prescription medications will affect them. Many think that genetic testing is crucial to the future of "personalized medicine," which tailors cures to people's genes. But few tests have undergone stringent scientific validation.
Mounting concerns have prompted the Food and Drug Administration to begin stepping in. In May, the agency scuttled plans by Pathway Genomics of San Diego to sell genetic tests in Walgreens stores. Several weeks later, the FDA sent letters to five companies that were selling tests over the Internet, declaring that their kits are medical devices and must undergo federal scrutiny. This week, the agency is convening a public hearing to debate what regulatory role it should play.
"It's come to the point where really there's a need for some oversight," said Alberto Gutierrez, who heads the FDA's Office of In Vitro Diagnostics. Results from questionable tests can be unnecessarily alarming, Gutierrez said, adding that, for example, some women have undergone surgery based on tests that purport to gauge the risk for ovarian cancer.
What's more, without a genetic expert to interpret the often-nuanced results of valid tests, patients who test negative might be falsely reassured, critics argue. Women might think they are safe from breast cancer, for example, and stop getting mammograms without realizing that they might still be in danger.