By the end of this decade, gene doctors promise to offer a kind of voyage into the future.
Their "time machine" will be blood tests that will screen you for dozens of genes and provide a statistical peek at your health. Want to know the probability of getting certain diseases, from Alzheimer's to colon cancer to alcoholism? They will tell you.
Scientists have touted such genetic information as a powerful tool. Armed with such knowledge, you could change your eating habits to reduce the risk of getting cancer or heart disease. Or you could begin regular checkups that might lead to an early diagnosis of life-threatening illnesses.
But that information might also carry troublesome side effects. Insurers might deny you health, life or disability coverage because of genetic tests. That's already happening in some isolated cases; the trend could accelerate as such tests become more common.
And some people might have emotional problems from learning they have untreatable, fatal diseases. Such problems could even cause a backlash against genetic testing. At Johns Hopkins Hospital, for example, many people prone to Huntington's disease -- a fatal, untreatable disorder of the nervous system that strikes during middle age -- are forgoing a test the hospital offers.
Consider the case of Victoria Allene Reis, a 40-year-old Californian who has had trouble getting health insurance ever since she took a genetic test for cystic fibrosis in 1989.
Results of the test -- which she took on the advice of an emergency room doctor -- were inconclusive. And she isn't being treated for the fatal lung disease, although she does have bouts with bronchial infections, said Mrs. Reis and a doctor who verified her account.
But health insurers have denied her coverage six times, she says.
The one company that agreed to insure her -- for $300 a month -- has excluded lung ailments from the policy. "If I had known it would have meant I wouldn't get insurance, I would not have had the test," she said.
The impact on her life has been profound. Without full health insurance coverage, she fears that she could incur huge medical bills, wiping out her family financially.
So she and her husband have put everything they own in the names of their children. "We don't have anything. I am not going to lose a home I worked 25 years for," said Mrs. Reis, a foster mother for handicapped children.
Although her story is not common, cases of discrimination based on genetic testing are likely to increase with the explosion of medical research expected in the next five to 10 years. As scientists decipher the body's complex genetic code, a new gene is discovered nearly every month.
Congress and several states, including Maryland, have considered laws to limit or prohibit insurers' access to information about genetic testing. Wisconsin and Arizona have passed such laws; Maryland's General Assembly decided this year to defer action until proposals are studied over the summer.
A recent report by a National Institutes of Health task force recommends a moratorium on the use of results of genetic testing by health insurers. It recommends that health care reforms prohibit denying anyone basic health coverage because of results of a genetic test. In addition, it says a person shouldn't be required to take a test or to give an insurer the results before getting insurance.
Health care reform is likely to solve the problem, many doctors and geneticists believe, if a basic level of care is offered to everyone, including those with pre-existing conditions. But other doctors say that if health insurers have any access to such information, they will use it to discriminate.
The issue of disability and life insurance appears to be more complex. Many people say everyone has the right to receive proper health care, but should society give everyone access to disability and life insurance?
"You can't allow people to go to a [life] insurance company and say, 'Give me a $5 million policy and you aren't allowed to test me for what I know I have,' " said Robert Hunter, president of the National Insurance Consumer Organization. "If you give one side a peek at everyone's cards and then let everyone bet, you won't have a fair bet anymore."
Theresa Morelli, a 30-year-old Ohio lawyer, applied for disability insurance after law school. She was denied insurance after the company read a note scrawled across the medical records in her doctor's office. That note said her father had died of Huntington's disease, which gave her a 50 percent chance of inheriting the gene -- and the disease.
Ms. Morelli, who lives in Steubenville, has refused to have the genetic test for the disease. She doesn't want to know the result -- and believes she risks losing health insurance if she takes the test.
"I have already been branded uninsurable by a disease my father allegedly had. . . . I feel I can't risk it. A person needs health insurance," she said.
Mr. Hunter says there are good arguments for putting some reasonable controls on the insurance industry. Perhaps, for instance, a person seeking only enough life insurance coverage to pay for a funeral or for covering a mortgage shouldn't have to submit health insurance information.
But insurers that handle disability and life coverage oppose any bar on their access to the results of genetic testing, says Debbie Chase, a spokeswoman for the American Council of Life Insurance.
"We know of no insurance companies that are asking applicants to undergo tests," she said, adding that companies don't routinely require genetic screening because the tests are expensive and imprecise.
Ms. Chase points to a perplexing problem regarding genetic testing: It is not an exact science.
"The . . . testing is more problematic than one might think," said Eric Juengst, chief of the Ethical, Legal and Social Implications Branch of the National Center for Human Genome Research at the NIH.
In some cases, as in Huntington's, a single gene causes a disease. More often, says Neil Holtzman, a Johns Hopkins pediatrician and geneticist, several genes or a combination of genes will give a person a higher probability of developing a disease.
For example, he said, "we know there are over 200 mutations of genes that can cause cystic fibrosis." Of those, six or seven genes are responsible for about 85 percent of the cases of the disease.
Another category -- perhaps the largest -- includes diseases caused by genetic defects or mutations that occur after a person is born.
For instance, Hopkins doctors recently discovered a gene that causes colon cancer in a small percentage of people. That gene often is found in people whose family histories include the disease. But doctors also have found an unrelated gene defect that occurs after birth and triggers the disease.
A test for the hereditary gene probably would only be given to families with several members who have suffered from it. But the general public might be screened for the defective gene.
Another problem with genetic testing: the emotional impact of knowing that you're likely, but not certain, to get a disease. That might cause some people to forgo genetic testing -- and a chance to detect disease at an early stage.
At Johns Hopkins Hospital, for example, researchers offer a test for Huntington's disease to members of families where there is a history of the disease. Before such a test was available, people with such a family history were surveyed and over whelmingly said they would take a test if it were offered.
But when confronted with taking the test, their decision often was agonizing. In the past seven years, 400 people have contacted the center, 200 have come in, and only 115 have agreed to be tested, says Ann Marie Cordori, a psychologist and coordinator of the Baltimore Huntington's Disease Presymptomatic Testing Program.
Most people tested and found to have the marker -- a "signpost" along the chromosome that tells doctors there is a 95 percent chance the gene is nearby -- don't become depressed or suicidal, she says. But some people have had problems.
For three generations, the women in Karen Tikkanen Wasson's family have died of Huntington's disease. She tried to live normally, not knowing whether she had the disease -- until one day in her late 20s, when she noticed potential symptoms.
"At that point I thought, 'What do I have to lose?' " said the 31-year-old in a phone interview from Pittsburgh.
The testing process took nearly a year, mainly because she had to collect blood samples from several relatives. "The entire process was excruciating," she said.
But on Sept. 29, 1990, she heard the words, "It is good news," from a Hopkins doctor. "It felt like I was given a new life."
People with Huntington's disease have few alternatives, though, because there is no cure or treatment. Doctors say that interest in widespread genetic testing may depend on whether people believe they can control the course of a disease by getting regular checkups or by changing their diet and lifestyle.
And the spread of genetic testing could depend less on technological developments than on public acceptance.
Dr. Juengst is skeptical that there will be mass screenings for dozens of diseases in the next five years. "Doing that sort of thing would only be a good idea if the public had a good grip on the meaning of the tests and if there were protections for the information."
But Paul Billings, an outspoken advocate of keeping test results private, says mass screenings are inevitable with a biotech industry eager to sell them.
"There will be a great deal of advertising about it," he said.