Genome Database Will Link Genes, Traits in Public View

But the rush to exploit genetic research for commercial purposes raises red flags for Deborah C. Peel, a psychiatrist and founder of Patient Privacy Rights.

"Personalized medicine will be a nightmare that drives up costs and doesn't address the sickest people or the most devastating illnesses," she said. "It is for-profit medicine at its worst, with a very nice name and propaganda that appears to value individuals. I am not opposed to making profits -- I am just for making profits in a way that does not destroy the privacy or lives of others."

Even Thakuria has concerns that some companies may draw unjustified conclusions from studies that have not been validated or are based on a small fraction of the genome. "There doesn't seem to be a very good vetting-out process," he said. "And I think this applies to almost every company right now offering this testing directly to the public."

One of the largest concerns of privacy advocates and civil libertarians is how gene-behavior links might be applied to large DNA databases assembled by law enforcement, which in about a dozen states now include samples from people who have been arrested but not convicted.

"When you have 6 million samples in a criminal database and there are some genetic markers that are claimed to [predispose someone to] substance abuse, mental illness and impulsive behavior, then you're going to see the further mining of this information in an attempt to classify and target groups of people as potential criminals," Mercer said. "That's one of the big fears -- that this trend is a precursor to a movement toward eugenics" -- the controversial idea of molding human heredity to bolster desired characteristics or eliminate undesirable ones.

A number of studies have attempted to find genetic links to shyness, intelligence, novelty-seeking and sexual orientation. But, said Mark Rothstein, director of the Institute for Bioethics, Health Policy and Law at the University of Louisville School of Medicine, "even if there is an association of varying degrees between certain genes and behavior, genetics is not destiny. My concern is that there is considerable risk that the research will be misused in a variety of legal and social contexts."

Rothstein raised other issues posed by genetic databases. Though the recently passed Genetic Information Nondiscrimination Act bars employers and health insurers from discriminating against a person because of genetic predispositions, the law does not outlaw discrimination by life, disability and long-term care insurers, he noted.

But Henry T. "Hank" Greely, a Stanford law professor, said focusing on associations alone misses the point. "If people understood that, for example, a 'violence gene' might change a person's risk of engaging in violent behavior from 5 percent to 7 percent, they would neither think about preventive detention nor think about eugenics," he said. "There's nothing wrong with the tool, and it may turn out to be medically important. What's wrong is the misunderstanding and misuse of the tool."

A Leap of Faith

The PGP, which began as little more than a conviction by Church that it could be done, won approval this year from the Harvard University Institutional Review Board, whose role is to ensure the safety of research subjects, to proceed with his plan to enroll 100,000 participants.

To sign up, a person must pass a 40-question exam that includes queries such as, "How much genomic material exists in a typical human cell?'' He must decide whether he is comfortable with the privacy risks, including the possibility that an insurer could peruse his data. Church plans to require volunteers to obtain the consent of their first-degree relatives, who also stand to be exposed by having a blood relative's DNA on view.

It was the review board's idea that Church become a participant.

"They actually felt I would get more involved," Church said. His wife reacted "very cautiously" to the idea, he said. She suggested they go on a "listening tour" to talk to other prospective volunteers and their families.

Eventually, Church's wife, genetics professor Ting Wu, and their daughter, now 17, consented to his participation, he said.

If PGP is to work, Church said, people are going to have to make a leap of faith.

"Perfect can be the enemy of the very good," Church said. "Just like when you go out and buy a car. You don't wait until they have a perfectly safe car. You say, 'Okay, 30,000 people die per year in the United States from car accidents. I'm going to roll the dice.' "

Staff researcher Magda Jean-Louis contributed to this report.