"We used to ask, 'Could this be genetic? Is there a genetic effect?' Now the question is, 'What genes are involved?'‚" said the University of Washington professor, genetics counselor and molecular researcher.
The next big revolution, already starting, is to understand how people - "big bags of genes interacting with our environment" - differ from each other and in response to environmental vagaries, Byers said.
The developments scare some physicians and the public, Byers said. "But it's something nobody should be afraid of - just a way of understanding who we are and what impact that has on all kinds of things."
He said DNA evidence presented during the O.J. Simpson trial and identification of a gene linked with breast cancer have made a big difference in "interest, enthusiasm and understanding about the relationship between genes and us."
Byers was here recently to give physician lectures, visit hospitals and see some patients with Dr. Berkley Powell, Kapiolani Genetics clinical geneticist.
The Seattle scientist has been providing genetics information for some Kapiolani cases involving disorders of molecules outside cells, in arteries, skin and blood vessels.
Byers works primarily with those rare disorders, which he said can result in fatal diseases because of brittle bones and fragile arteries that tear or rupture. He runs the only biochemistry diagnostic program in the country for such disorders.
Among island patients, he studied a girl with a bone disease and her parents and found the girl had a gene mutation that wasn't present in her parents.
He was able to assure the parents if they had more children they wouldn't be at risk, he said.
Byers, editor of "American Journal of Human Genetics," said new strategies allow geneticists to look at many different regions of genes simultaneously to see whether they're being passed from generation to generation in families.
Identifying specific genes linked with uncommon disorders may reveal variations that expose people to more common diseases, such as diabetes, high cholesterol and blood pressure, he said.
The new techniques allow geneticists to narrow the hunt for genetic culprits to a small area, Byers said. It's like searching the entire country on a map of the United States, then narrowing it to a state, city and finally a house, he said.
"There are all kinds of things we're going to discover and we're not yet really very well prepared for understanding what we're going to do and how we're going to deal with them," Byers said.
How the knowledge is translated and applied is "probably the most important thing in the next generation of medicine," he said. Findings not only will affect decisions on therapy treatment but "will have a big intellectual effect on how we look at things," he said.
Geneticists are beginning to realize changes in genes may affect people with schizophrenia and manic depression illness - areas involving social policy, Byers said.
Some people may be resistant or more prone to infections because of their genetic nature, Byers said. "Our genes are out there operating on everything."
As technology develops, however, it raises serious policy questions because of legal, ethical and social implications, he said.
Concerned geneticists are talking to ethicists, lawyers and politicians, he said. "If we find something, . . . do we intervene? Can we make a difference in outcome, knowing something at childhood?"