Genetic testing can tell whether a person is at risk of developing cancer, heart disease or other ailments. In the future, it may be able to prevent diseases from developing or even cure them. But many Americans refuse the tests for fear that insurers or employers will use the information against them.

After a 13-year struggle to solve the dilemma, a bill outlawing such discrimination, introduced by Sen. Olympia Snowe, has passed the Senate and the House and awaits a signature from President Bush.

The new law will prohibit health insurers from basing coverage or premium decisions on the findings of genetic tests. And it will forbid employers from using genetic data in decisions on hiring, firing and promoting employees.

Sen. Snowe hailed the passage of the Genetic Information Nondiscrimination Act as “unique and groundbreaking.” In a statement, she said, “For the first time, we are acting to prevent discrimination before it takes firm hold – so that Americans can act to improve their health without fear.”

At stake is not only an individual’s safety in getting information about his or her genetic makeup, but also the scientific community’s need for millions of genetic tests to continue the exploration of the human genome.

An open question is whether this new law will allay individuals’ fears that, if they agree to genetic testing, the results will somehow lead to discrimination in health care or employment or in personal embarrassment if the results become known. We all have seen how hard it is to keep secrets in this age of leaky and stolen databanks.

Some supporters of the law suggested that the strictures on health care insurers should be extended to providers of life insurance, long-term health insurance and disability insurance. They, too, could use genetic information to discriminate. This was likely left out of the bill to ensure its passage.

The insurance industry understandably wants all the information it can get in its actuarial research and in determining whom to insure and how much to charge. Other business groups fought the legislation for many years. The United States Chamber of Commerce led the opposition, fearing steep financial penalties for violations and interference with normal business practices.

Framers of the law foresaw the likely need for further legislation as the new world of genetic research expands. They ordered the creation in six years of a Genetic Nondiscrimination Study Commission to review the developing science of genetics and make recommendations.

The new law can be welcomed as a long-overdue first step in promoting genetic research and protecting against abuse.