A CHANCE TO PEEK INTO THE FUTURE—at least one possible future—is always a tempting fantasy. But would you take it? And if you didn't like what you saw, how hard would you try to change it? After almost 20 years spent reading, mapping and analyzing human DNA, researchers at the National Human Genome Research Institute (NHGRI) believe that personal genetic information is nearly ready for use by consumers in managing their health. To determine whether that is so, however, the institute is launching a large-scale study.

The year-long Multiplex Initiative will ultimately involve thousands of subjects, who will be offered a personal genetic report card based on screening for gene variations associated with increased risk for major diseases. The investigators are interested in how many take up the offer and why and how participants respond to their results. The researchers also hope to gain insights into the best ways for health professionals to communicate information about genetic risk.

“Our major outcomes and measures are going to be [whether] they understand the tests, because this is hard stuff to package for the general public,” explained senior investigator Lawrence Brody of the NHGRI's Genome Technology branch, when announcing the initiative in early May in Washington, D.C. “And whether or not they find the test useful, what are their attitudes about it.”

The investigators are recruiting among members of the Henry Ford Health System, a Detroit-area HMO, and will follow up with participants to see if learning genetic information about themselves prompts them to seek out wellness programs or change any behaviors. As many as 10,000 potential participants between the ages of 25 and 40 will have received mailed invitations to be screened for versions of some 15 genes associated with higher risk for conditions such as coronary artery disease, osteoporosis, lung cancer, colorectal cancer and melanoma.

“I think the NHGRI study is very valuable,” says Catherine Schaefer, the lead investigator of a larger Kaiser Permanente research project that is currently recruiting among 3.5 million members of that California HMO. Schaefer is gathering DNA samples and other health information in the hope of discovering new gene variants that confer disease risk or protection. “It's important to learn how people respond to this very complex genetic information,” she says.

In the past, genetic testing has been mostly limited to single-gene diseases, such as Huntington's or cystic fibrosis, where the grim association between particular genes and eventual illness is clear and certain. Complex conditions, in contrast, might involve the activity of hundreds or thousands of genes in different aspects or stages of the disease, and diet or other environmental factors may also interact with those genes over a lifetime.

“For better or worse, we've convinced the public that genetics is very important and deterministic,” Brody explained. “And now we have to back off of that a little bit.”

All the conditions included in the Multiplex Initiative screening are preventable, so participants can decide for themselves whether the results are worth acting on. Current measures of future risk typically rely on symptoms that have already appeared, such as high blood pressure or spinal degeneration, noted NHGRI director Francis Collins during the announcement. Genetic testing, he said, gives people an opportunity “so that you can begin to practice prevention before you're already half in the grave.”