Doctors wary of new home-based genetic tests for potential diseases

• Commercials hawking prescription drugs directly to consumers have driven doctors crazy for years.
• Now comes a new kind of marketing that is already troubling some medical professionals: at-home genetic testing.
• This week, in a small but dramatic move validating the popularity of the online approach, DNA Direct will begin offering two popular breast cancer tests created and conducted by Myriad Genetics, the most visible player in the field of "predictive medicine."
• DNA Direct's breast cancer testing plans are modest.
• Initially, it will offer two of Myriad's less-complicated tests, which screen for only a few mutations on the key genes.
• DNA Direct expects the tests to cost about $300 each.
• An increasing number of online startups are marketing tests that can show predisposition to any number of maladies, from breast cancer to blood clotting.
• They are exploiting the blizzard of genetic discoveries reported almost daily since scientists published the complete map of human genes five years ago.
• The tests are cheap, easy to administer -- they often involve just a cotton swab inside the cheek -- and the results are available online, cutting the visit to the doctor's office.
• Plus, the companies note, the test results aren't usually jotted down on official medical histories, which keeps sensitive information from insurance companies.
• "We are empowering patients with knowledge," said Ryan Phelan, who recently launched the San Francisco-based testing company DNA Direct.
• The company currently offers genetic testing, a la carte, with prices from $199 to $380, for predisposition to cystic fibrosis, blood clotting, iron overload and a heightened risk for lung and liver diseases.
• Testing positive can help customers make lifestyle changes to prevent the onset of disease, the company says.