The Government Accountability Office (GAO) recruited five volunteers to send genetic samples to four unnamed consumer genetic testing companies to determine their risk of developing prostate cancer or diabetes. The result? Genetic test results were highly inconsistent, with four out of five donors receiving a diagnosis that differs with their actual medical and family history. "Assuming these tests are credible, one would expect that identical DNA would receive identical predictions," the GAO's Gregory Kutz said in a hearing, as quoted by Reuters.
The tests, which range in price from $300 to $1000, started out as tools for consumers to learn about their ancestry. But they've evolved into predictive tests that claim to assess how a person will respond to a drug, or how likely a user is to develop certain diseases. The agency is concerned that consumers will make medical decisions based on data that hasn't been tested for accuracy. As one expert observed in the GAO report, "the fact that different companies, using the same samples, predict different directions of risk is telling and is important. It shows that we are nowhere near really being able to interpret [such tests]."
In addition to misleading results, the GAO found 10 "egregious examples" of misleading marketing. One firm sells supplements that could "repair DNA damage." Two companies claim they can predict which sports a child would do well in, while another told one of the GAO's volunteers that she could secretly test her fiancé's DNA--an act that's illegal in 33 states. Finally, experts were horrified that one woman was told she almost definitely would develop breast cancer.
The GAO's finding doesn't bode well for consumer genetic testing industry, which up to this point hasn't faced any FDA regulation. Test makers Pathway Genomics, Knome, Navigenics, deCODE Genetics and 23andMe have all received letters saying that their test will have to be cleared by the agency.