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? 

Such investigations have only increased in frequency. Last November, New York’s Department of Health sent letters threatening fines and jail to 26 online gene-testing companies, saying they are violating state law by offering services without the involvement of “a qualified person, such as a physician licensed to practice medicine in this state or other authorized ordering source....” Many have submitted business plans for the state’s review and are cooperating fully. And in June, the state of California sent letters to 13 genetics firms requiring proof that they are complying with state laws that require, among other things, that physicians are ordering the tests on behalf of their patients.

“Without the proper guidance, it’s difficult for people to figure out whether it’s appropriate to spend money for that kind of test,” says Erin Tracy, a physician at the MGH who wrote an article on the subject in the journal Obstetrics & Gynecology.

But there’s a fine line between protecting consumers from uninterpreted information and preventing them from learning possibly crucial facts about their health. Altshuler, the MGH physician and geneticist, doesn’t buy the idea that simply offering up genetic data is harmless at worst and empowering at best. “If a test leads to further tests, and those further tests have side effects—they involve a biopsy, for example—they can lead to anxiety or suffering,” he says. He expects that once the current fad for testing fades, firms that don’t offer anything of value won’t survive. “If recreational users can’t explain to their friends why it’s worth $1,000, it won’t go anywhere,” he says.

For now, 23andMe’s Avey suggests, the firm’s most important role might involve connecting consumers with similar traits (imagine a Facebook page for, say, cystic fibrosis patients) and perhaps sparking grassroots research efforts. Researchers often are stymied by a lack of study participants. But if more people learn through genome scans that they’re susceptible to a particular disease, they may be more likely to sign up.

Eventually, the kind of information provided by testing firms will play an important role in modern medicine, with more and more disease-causing SNPs identified and the impact of environmental and behavioral factors sorted out. And it’s that promise that keeps Jay Cross, the two-time heart attack victim, hanging in there with his 23andMe account, through which he continues to get updates at no additional cost. He thinks that if he’s patient, the science will catch up to the hype that lured him in. “I thought it was a lot closer to being a bottle of wine that was ready to drink,” he says of his DNA scan. “But essentially what I bought was a Bordeaux future.”

  Dossier

1. “Are Doctors Prepared for Direct-to-Consumer Advertising of Genetic Tests?” by Erin Tracy, Obstetrics & Gynecology, December 2007. Clear-minded and succinctly worded, Tracy’s analysis cites both anecdotal evidence and numerous studies to suggest that DNA vendors are taking advantage of consumers—and to argue that genetic testing needs to be reined in.

2. “Breakthrough of the Year: Human Genetic Variation,” by Elizabeth Pennisi, Science, December 2007. With this opus in praise of new technologies able to sequence DNA and assess variations in genomes, Pennisi argues compellingly that the best is yet to come.

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