Monday, October 27, 2008

What Gene Tests Can Really Tell You

What Gene Tests Can Really Tell You


If Greg Lennon is right, then the personal genome gold rush has a major flaw: There's not much gold there—not yet.

In the past year, companies have launched high-profile efforts to read the future in people's genes. For $399, a Google (GOOG)-backed startup called 23andMe collects saliva samples from its customers, looks at nearly 600,000 genetic variations in their DNA, and describes what these reveal about the donor's traits, ancestry, health, and risk of diseases. Another company in the headlines, Navigenics, not only extracts information from 1.8 million variations, or "markers," in a tissue sample, but also taps the expertise of genetic counselors and scientists at Harvard and other institutions. The price: $2,500, plus a $250 annual fee to get customized bulletins on the latest discoveries. "The technology lets you know who is at risk for Alzheimer's, diabetes, cancer, and other diseases," says Navigenics Chief Executive Officer Mari Baker.

Not so fast, says Lennon, a PhD geneticist and entrepreneur. Contrary to the hype about genetic testing, this first wave of direct-to-consumer ventures is likely to be a bust, he believes. The slim, soft-spoken Lennon, 51, is in a good position to know. He's a veteran of both the government's Human Genome Project and biotech startups, and he has ridden the roller coaster of hype and failure. He predicts that the payoff from the explosion in knowledge about human genes—and from the business model espoused by 23andMe and its ilk—won't come for 10 years. Right now, the personal gene-testing companies glean medical insights from individual bits of DNA, rather than from whole genes. So far that may be no better than what is learned the old way, from family histories: "Most people can save themselves $1,000 just by asking Aunt Clara what runs in the family," says Lennon.

"PARLOR GAME"

Such skepticism is surprisingly common among scientists. "I see personal genomics as a kind of recreational parlor game rather than a useful endeavor," says Dr. James P. Evans, professor of genetics and medicine at the University of North Carolina, Chapel Hill. "There's a potential for harm in false reassurance and false anxiety, but mostly it's a waste of money."

Of course, even parlor games can make money. And in the long run, Lennon, Evans, and others think that reading people's DNA will prove to be a tremendous medical boon. Lennon himself is a believer and continues to place bets on the field: His latest venture, called SNPedia, is a repository for all the data streaming from around the world linking genetic variations to health and disease. Launched in 2006 by Lennon and a computer-whiz buddy, it's a Web site supported by ads and licenses, which anyone can browse for free.

But Lennon and many academics contend that the claims of the new gene-testing startups are premature and overblown. 23andMe, which is also backed by biotech powerhouse Genentech and was co-founded by Anne Wojcicki, wife of Google's Sergey Brin, promises on its Web site to "help you understand how your genetics influences more than 80 diseases, health-related conditions, and traits." Another gene-testing company, deCODE Genetics (DCGN), also makes some grand claims on its deCODEme Web site: "You'll find out where your ancestors came from" and "make more informed decisions about your health." Yet the information we can extract from common DNA variations falls far short of a predictive blueprint for future health. It provides only small statistical links to illness, along with imperfect hints at a customer's origins.

This reality struck Lennon when he had his own DNA tested several years ago with the same basic technology now marketed by 23andMe, then analyzed it using his SNPedia database. Getting the results seemed exciting at first, he says. He was intrigued to learn he has genetic markers linked with an increased risk of heart disease and decreased risk for certain cancers.

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