Are Genetic Tests Really Useful

I  was comparison shopping in New York's Soho neighborhood last week. The product? My DNA—and what it can tell me about when, or if, I might have a heart attack and keel over one day. Or if I have a high risk factor for acquiring exfoliate glaucoma or Alzheimer's disease. Better news would be that I have genetic markers protecting me from certain dreaded maladies.

EXPERIMENTAL MAN David Ewing Duncan explores advances in personalized medicine and what they can tell us about ourselves.

In a few minutes I'll know my results for 17 gene-influenced diseases, delivered in a most unlikely place: A posh storefront that looks like an art gallery, with bare-brick walls and hardwood floors. It's opening day for Navigenics, a company selling what may be a first for on-site retail: genetic testing for the healthy, with tests ordered and results delivered online.

Piled on a countertop are boxed kits containing small vials that a customer will fill with DNA-rich saliva and mail in to be tested on a gene array—a chip that locates and identifies more than 1 million genetic markers, including those which scientists have connected with certain diseases.

Navigenics, based in Redwood Shores, California, is the latest company pushing us into the new world of direct-to-consumer genetic testing. I already have results from the two other major online genetic-testing companies that opened last fall: 23andme in Mountain View, California, and deCodeme in Reykjavik, Iceland.

The three companies do what the Web loves to do: push the edges of technology and commerce to see if they can launch new revolutions—and make money.

The issue is whether the science in the fledgling field of genetic forecasting is ready to be peddled to healthy individuals like an iPod. As Harvard geneticist David Altshuler asked me: "Just because you can do something, should you?"

As we hear almost daily reports about scientists discovering genes for this or that trait, a vacuum has formed in what this information means for individuals. So far, the medical community has largely abrogated its role to help us make sense of all this research. This has allowed commerce to step in and use new, cheaper gene-testing technologies to bring DNA directly to the people.