Discovery of Alzheimer’s Gene Stirs Ethics Debate : Medicine: Questions are raised on prenatal testing and the effect of diagnosis on adult victims’ quality of life.
The discovery of a defective gene that apparently causes an inherited form of Alzheimer’s disease, announced Thursday, has re-energized the ongoing debate about the ethics of diagnosing such disorders either prenatally or after birth.
The majority of researchers and ethicists agree on the importance of diagnosing a disease such as Lesch-Nyhan syndrome, which strikes soon after birth and produces a short, brutally painful life. But the stakes are far different in diagnosing a disorder, such as familial Alzheimer’s, which produces no symptoms until it strikes as early as age 45.
The first and obvious issue is whether or not to abort a fetus who will certainly go on to develop the disease. But perhaps even more important are the crucial issues of quality of life.
Will an adult who knows he or she will develop Alzheimer’s be able to acquire health insurance? Will an employer hire such an individual knowing that his or her abilities will be curtailed during their most productive years? And how will such knowledge affect the individual’s lifestyle and mental stability?
Such questions have seemed largely theoretical in the past because genetic tests have been available primarily for rare diseases, such as Huntington’s, which affects only an estimated 25,000 people in the United States with perhaps another 125,000 at risk.
But familial Alzheimer’s disease strikes as many as 50,000 new victims each year, fully 20% of all Alzheimer’s patients. That incidence raises the stakes substantially.
“I think it has enormous reverberations,†said psychologist Nancy Wexler of Columbia University, president of the Santa Monica-based Hereditary Diseases Foundation. “It raises the possibility of having enormous numbers of individuals who would seek information, even though they might not desire testing. We don’t have enough counselors to handle inquiries about diseases that we already have tests for, much less this one.â€
Researchers have been debating the ethics of genetic testing for over a decade since the potential for such tests became clear, and some consensus is emerging. But the questions have become more urgent for researchers such as molecular geneticist Merill D. Benson of Indiana University, discoverer of the new Alzheimer’s gene, who are now faced with such tough choices.
Benson has already identified at least two members of a large family who have the Alzheimer’s gene and thus are almost certain to develop the disorder, but he has not yet told them and is agonizing over the prospect. “We’ll feel much more certain about telling these people after other researchers have confirmed our findings,†he said Friday. “But many don’t want to know.â€
He is also testing members of the next generation of that family and is virtually certain to find that some of them have the defective gene. He said he will tell them--if they ask--when they get old enough to marry and seek genetic counseling. He has no plans to do prenatal testing soon.
Benson is facing these questions somewhat in isolation: The defective gene has been linked to Alzheimer’s in the only family studied so far. It is not yet certain that the presence of the gene guarantees that its possessor will develop the disorder.
Nonetheless, many researchers are confident that the same defective gene will be identified in other families, sharply increasing the number of people in the testing pool.
Researchers have recently begun formalizing the ethical debate. The Human Genome Project, the $3-billion effort to identify each of the 100,000 genes that make up the blueprint of human beings, has established an Office of Ethical, Legal and Social Issues to address these questions and try to provide guidelines for the future. Geneticist James D. Watson, head of the project, has allocated 5% of its funding to study such issues--the first time substantial funds have been available for research.
The debate centers on three key issues: employability, insurability and prenatal testing. Some consensus is emerging on each.
On the employment issue, “The bottom line is that having a gene that is presymptomatic--present but not causing any harm--could be seen as having a handicap,†said ethicist Kathleen Nolan of the Hastings Center, a think tank for the study of ethics. “An employer might seek to avoid such individuals. I think that is discrimination, if such individuals are able to do the job at the time they were hired.â€
In theory, such discrimination is illegal under the Americans With Disabilities Act of 1990, said ethicist Thomas H. Murray of Case Western Reserve University, chair of the Ethical, Legal and Social Issues working group. “Unfortunately, the Equal Employment Opportunities Commission is writing the rules for implementation of that act and they do not encompass genetic testing,†he said.
“Under the proposed EEOC rules, an employer would be able to test for damn near anything . . . and then reject an applicant under some pretext,†he added.
Insurance is a particular problem, noted lawyer Mark Rothstein of the Health Law Institute at the University of Houston. By definition, he said, insurance represents a way to share the risk of unknown contingencies among a large group. When those contingencies become known, as through genetic testing, the balance of risks changes sharply.
On the one hand, a person who knows he will develop Alzheimer’s might be tempted to obtain extra medical and life insurance to cover his medical expenses and provide for his family after death. The insurance companies, on the other hand, will try to exclude such individuals in order to keep premiums and costs down. “The implications are rather staggering,†Rothstein said.
Some ethicists have suggested that insurance companies be forbidden to require genetic testing before issuing coverage, but many believe that will not work. Some companies already find ways to get around similar bans on AIDS testing, Murray said, and the same thing is likely in genetic testing.
The most equitable solution, Murray said, would be the development of a national health system “to ensure that all people who need care get it.†Such a system would also have provisions to ensure survivors’ well-being, he added.
But the most emotion-charged issue is that of prenatal testing. Few deny that prenatal screening is valuable for severe genetic disorders, such as Lesch-Nyhan, which is characterized by severe retardation, violence, self-mutilation and an early death. Therapeutic abortions prevent excess suffering by child and parents alike.
In contrast, most researchers agree that prenatal screening for genetic disorders such as Alzheimer’s should be discouraged. “I would certainly not recommend to anyone that they have prenatal screening†for such a disease, emphasized Murray. “Even at the worst, the fetus would have the prospect of 45 years of a normal life. By that time, we can expect some reasonable treatments.â€
Nonetheless, added Nolan, “it will necessarily be a very individual decision, and a painful one for many families.â€
Researchers so far have very little experience to draw on in making ethical decisions about such issues, but what experience they do have is beginning to produce some unexpected results. The most surprising involve Huntington’s disease.
Despite the growing number of centers that are offering testing for adults at risk of developing Huntington’s, Wexler said, “I would guess that fewer than 1,000 people have been tested worldwide.†The vast majority of individuals at risk who receive genetic counseling decide that they don’t really want to know. Chances are, she said, the same thing will happen with Alzheimer’s.
