Congressional efforts to set federal standards to protect people from genetic discrimination go back more than a decade, to a time when there were only a small number of genetic tests. But now, with the mapping of the human genome in 2003, people have access to far more information about their hereditary disposition to such crippling afflictions as cystic fibrosis, Huntington's disease or Lou Gehrig's disease.

Bill sponsors said that has increased the likelihood that a prospective health insurance company or employer will reject a person because of concerns that person will suffer a costly disease in the future.

The Senate passed genetic nondiscrimination bills on unanimous votes in 2003 and 2005 but couldn't get the House to act. A year ago the House approved a White House-backed bill on a 420-3 vote.

Senate action on that legislation has been slowed by Sen. Tom Coburn, R-Okla., who joined some business groups in warning that the bill could encourage a flood of lawsuits.

A compromise worked out earlier this week tightens language to ensure there is a ''firewall'' between the part dealing with health plans and the section regarding employment, so as to discourage inappropriate claims.

It also makes clear that, while individuals are protected from discrimination based on genetic predisposition, insurance companies still have the right to base coverage and pricing on the actual presence of a disease.

''We certainly improved the bill from a liability standpoint,'' said Coburn, an obstetrician. He said he was an adamant supporter of the legislation ''if it is not designed to feed the trial lawyers.''

Rep. Louise Slaughter, D-N.Y., chief House sponsor of the bill with Rep. Judy Biggert, R-Ill., said the House would ''get it out to the White House as quickly as we can.'' Slaughter, who first introduced a genetic discrimination bill 13 years ago, said personalized medicine advanced by genetic research has ''the potential to save billions of dollars in health care costs.''

Dr. Francis Collins, genetics chief at the National Institutes of Health, said it's difficult to know how often genetic discrimination has occurred because victims are reluctant to come forward.

He cited one example of a Texas-based railroad that once conducted genetic tests on workers complaining of carpal tunnel syndrome in an effort to argue the injuries weren't job related if patients had a genetic predisposition.

''All of us carry glitches in our DNA and we're learning more and more about those every day,'' he said. ''A system that allows that information to be used to deny people health care or a job is a system that has lost its way. This is a civil rights issue and it's high time we took care of it.''