Elation ran high when Lap-Chee Tsui of the Hospital for Sick Children in Toronto and Francis Collins of the University of Michigan jointly discovered the cystic fibrosis gene in 1989. Cystic fibrosis is the most common genetic defect resulting in the deaths of young Americans and some estimates are that up to 4 percent of all Caucasians carry the defective gene.

Some reports at the time erroneously stated that the discovery of the gene would soon lead to a cure through genetic engineering techniques that would swap the defective gene for a normal one. This probability lies well in the future.

A much more realizable goal is the massive testing of the population for the gene thereby letting persons of child-bearing age know whether their offspring would be at risk of having the disorder. However, two recent reports in the journal Science, published by the American Association for the Advancement of Science, indicate that unexpected problems from several quarters have put the testing program on indefinite hold.

No sooner had biotechnology companies began work on a test for the cystic fibrosis gene than the American Society for Human Genetics called for a moratorium on widespread population screening. The rationale was that no current test would give completely accurate results.

Not all cystic fibrosis cases are caused by the single genetic defect isolated by Tsui and Collins. While it is responsible for around 70 percent of the cases, the remainder result from approximately 10 other defects on the same gene. Thus a couple could stand a good chance of having a child with cystic fibrosis even if the test had proven negative.

Conversely, a positive test is not a clear-cut indication that a couple will have children with the disease. If both parents carry the defective gene, there is about a 1-in-4 risk that any offspring will be born with cystic fibrosis. More likely is the probability that only one parent will test positive for the gene. This couple’s odds for having a child with cystic fibrosis jumps from 1 in 2500, the norm for the general population, to 1 in 400. Even this is not definite because the parent that tested negative might be a carrier of one of the yet unidentified mutations. Based on the uncertainties involved, many experts are urging that only persons from high-risk families be tested until pilot programs can raise the current 70 percent reliability to somewhere in the 90 percent-plus range.

A few commercial companies have already gotten into the testing for cystic fibrosis, a potentially huge market. Integrated Genetics in Framingham, Mass., offers the test only to those with a family history of the disease but other firms, Collaborative Research in Bedford and Gene Screen of Dallas, offer the test to anyone. Nowhere in the United States, however, is there a major pilot project designed to iron the “bugs” out of the testing program.

Although few will say so, one of the major reasons is that, with no cure for cystic fibrosis, couples testing positive are likely to increasingly resort to abortion as the safest alternative to the risk of bearing a child with the disease.

The Cystic Fibrosis Foundation, for example, should be a prime source of testing funds. Instead, the foundation stays completely away from testing, stating that its mission is to find a treatment and cure for the disease, not to prevent it. While the foundation officially denies that abortion played a role in this decision, unofficially directors were afraid that to embrace testing, and tacitly the aborting of affected fetuses, would cost them financial contributions.

The National Institute of Health (NIH) has adopted a similar posture. Geneticist Tom Caskey of Baylor College of Medicine criticizes, “NIH loved cystic fibrosis testing a year ago,” but now will not even accept applications for testing projects.

“We are in a mess,” says Caskey, referring to the need for a pilot program. NIH’s Elke Jordan denies abortion has anything to do with the decision, saying that the pilot programs simply do not fit any of their funding activities.

Even if the legal and moral quagmire that is the abortion debate is put aside, genetic testing does not have a good track record. Only one, the testing for Tay-Sachs disease among Ashkenazi Jews, has worked really well. This, however, involved a very limited population that could be easily screened and counseled as to the meaning of the test.

One more similar to the proposed cystic fibrosis screening, that for sickle cell anemia among blacks, has been a disaster. This genetic disease affects every 1 in 400 American blacks but, because of poor counseling and education, many who tested positive thought they were going to come down with the disease. In many cases persons who tested positive were denied health insurance and even lost jobs because of ignorance as to the meaning of the test. Whatever testing program for cystic fibrosis ultimately evolves, it must be preceded by an intensive educational program.

Dorothy Nelkin from New York University and Laurence Tancredi of the University of Texas Health Center question the ethics of telling people they have tested positive for some genetic disease for which there is no cure. In an article reprinted in “Headline News, Science Views,” a recent publication of the National Academy of Sciences, the authors present the problem of a healthy young woman whose genetic screening, done for an entirely different reason, showed she carried the gene for Huntington’s disease, an invariably fatal brain disorder.

Should the unsuspecting young woman be told she will likely start developing symptoms of the degenerative brain disorder by age 40? In this instance the person is being told early of a future death sentence since there is no cure. In other instances, such as with cystic fibrosis, a young couple may be sentenced to years of needless worry about their children or even elect never to have them. Until the reliability far exceeds the current 70 percent, perhaps it is better to remain in ignorance.

Looking beyond the difficulties and ethics of testing, there remains the question as to how the results of gene testing will be used. Does a company with a comprehensive health program have the right to know that a prospective employee carries a genetic defect that could result in costly hospitalization or an early disability retirement? Should a person be denied a job around certain chemicals if they have a predisposition to cancer? Can an insurance company ask for a genetic profile before issuing a policy? Does patient privacy and confidentiality come before the public’s right to know. Particularly worrisome is the contention by some individuals that abortion should be mandatory if the testing of a fetus reveals a genetic defect that is sure to prove expensive to society.

The discovery of the cystic fibrosis genetic defect was a major accomplishment that heralds many such discoveries in the years to come. Problems of counseling, testing, and, above all, ethics must be worked out before discovery can be equated with therapy. Look for this entire field to be enveloped in controversy for years to come.

Clair Wood, a science instructor at Eastern Maine Technical College, is the NEWS science columnist.