On the face of it, these study results seem to underscore the promise of genetic testing. But the blood test that the Wake Forest scientists developed cannot predict which men will get aggressive cancers, and merely knowing you have a heightened risk of prostate cancer could lead to excessive screening, unnecessary surgery and complications.

The Wake Forest scientists have formed a company, Proactive Genomics, hoping to market their Focus5 blood or saliva test this summer. But even though the science behind the test is remarkable, questions about how the results may be used also underscore the unintended consequences that may come with widespread genetic testing. What will a patient do if he learns he has 10 times the normal risk of prostate cancer? And what happens when deCODEme customers see they have a high risk of, say, heart disease? Should they go on a diet? Start exercising more? See a doctor? 

With most mail-order tests, consumers are left to interpret and perhaps act on the information they receive. Navigenics, deCODEme and DNA Direct offer customers access to counselors who can interpret the results, but many others only provide Internet links to studies showing the underlying research. And although most companies include caveats regarding any connections between their services and medical diagnoses, that may seem disingenuous when the information consumers receive apparently has a crucial connection to their current and future health. “No matter how often these Websites’ warnings are repeated, individuals may have a difficult time accepting them,” says Greg Feero, chief of the genomic-health-care branch of the National Human Genome Research Institute.

“Scanning someone’s genome is a personalized service,” says Jesse Reynolds of the Center for Genetics and Society. “But with most of these tests, it’s done in the absence of actually communicating with anyone.” Reynolds’s main worry isn’t that people will begin flooding doctors’ offices with deCODEme printouts. Only about 800 physicians in the United States have significant training in genetics, leaving the rest ill equipped to interpret the results. He actually fears the opposite will happen: A customer of a genome-testing outfit who learns he has only a modest risk of heart disease could presume he’s in the clear, even if his lifestyle leaves much to be desired. “I’m concerned that people could underreact,” Reynolds says.

For now, regulation of genomic-testing services is minimal, and that leaves consumers with few assurances about the accuracy or value of the information they’re buying. “There’s a basic lack of oversight, and that makes it difficult to determine which tests are ready for prime time,” says Gail Javitt, law and policy director of the Genetics & Public Policy Center at Johns Hopkins University in Baltimore. “There are very few barriers to market entry for these tests.”

But state regulators, increasingly, are taking notice. In September 2007, for example, testing service Myriad Genetics launched an advertising blitz promoting BRACAnalysis, its test (which must be ordered by a physician) for identifying the BRCA1 and BRCA2 mutations. That sparked an investigation by the Connecticut attorney general’s office into the truthfulness of the ads (Myriad is cooperating fully in the investigation).