TIME: Almanac 1990/1990 Time Magazine Compact Almanac, The (1991)(Time).iso/time/032089/03208900.004

Text File | 1990-09-21 | 13KB | 227 lines

SCIENCE, Page  70

The Perils of Treading on Heredity

Uncontrolled tampering with DNA could stir up a host of ethical dilemmas

     By  PHILIP ELMER-DEWITT

    The prospect is intoxicating. By mapping and manipulating tiny
genes, man could conceivably conquer diseases, improve upon his
natural abilities and perhaps even control his own destiny. But
just because miracles might someday be possible does not
necessarily mean that they should all be performed. The tools of
molecular biology have enormous potential for both good and evil.
Lurking behind every genetic dream come true is a possible Brave
New World nightmare. After all, it is the DNA of human beings that
might be tampered with, not some string bean or laboratory mouse.
To unlock the secrets hidden in the chromosomes of human cells is
to open up a host of thorny legal, ethical, philosophical and
religious issues, from invasion of privacy and discrimination to
the question of who should play God with man's genes.

    The opportunities and dilemmas created by the new genetic
knowledge begin even before birth. It is already possible, through
a variety of prenatal tests, to determine whether a child will be
a boy or a girl, retarded or crippled, or the victim of some fatal
genetic disorder. The question of what to do with that information
runs squarely into the highly charged issue of abortion. Many could
sympathize with a woman who chooses to terminate a pregnancy rather
than have a baby doomed to a painful struggle with, say, Tay-Sachs
disease or Duchenne muscular dystrophy. But what about the mother
of three daughters who wants to hold out for a son? Or the couple
that one day may be able to learn whether an unborn baby has a
minor genetic blemish? Only the most hardened pro-choice advocate
would argue that prospective parents have the right to abort fetus
after fetus until they get the "perfect" baby.

    Complicating such decisions is the fact that genetic
prognostication will probably never be an exact science.
Technicians may someday be able to determine that a fetus has a
predisposition to heart disease, certain cancers, or a variety of
psychiatric illnesses. But they will not be able to predict
precisely when -- or even if -- the affliction will strike, how
severe it will be and how long and good a life the baby can expect.
As scientists learn to detect ever more minute imperfections in a
strand of DNA, it will become increasingly difficult to distinguish
between genetic abnormalities and normal human variability. "We
haven't thought much about how to draw the line," admits Arthur
Caplan, director of the Center for Biomedical Ethics at the
University of Minnesota. "It is going to be one of the key ethical
challenges of the 1990s."

    History shows that genetic misinformation can be severely
damaging. Take, for example, the supposed link between the XYY
chromosome pattern and criminal behavior. In 1965 a study of
violent criminals in a Scottish high-security mental institution
found that a surprisingly high percentage had a particular
chromosomal abnormality: in addition to the X and Y chromosomes
normally found in men, each carried an extra Y, or "male"
chromosome. The press and public seized on the idea that these
so-called supermales were genetically predestined to a life of
crime. That interpretation proved false. Further investigations
showed that the vast majority of men with the XYY pattern -- an
estimated 96% -- lead relatively normal lives. But before the
matter was put to rest, a variety of measures were proposed to
protect society from the perceived threat. One group of scientists
urged massive prenatal screenings, presumably to allow parents to
arrange for abortions. Others initiated long-range studies to
identify XYY infants and track their progress over the years
through home visits, psychological tests and teacher
questionnaires. These dubious efforts were eventually abandoned,
but not before a group of innocent youngsters had been unfairly
labeled as somehow inferior.

    Adults could be wrongly branded as well. Life- and
medical-insurance companies might one day require that potential
customers have their genes screened, presumably so that people
likely to develop fatal or disabling diseases could be charged
higher premiums, or possibly turned away. Insurers have already
used a similar policy to avoid covering individuals at high risk
for AIDS, a practice now banned in several states. Unless it is
prohibited by law, employers could conceivably try to guarantee a
healthy work force by asking job applicants to submit to genetic
screening. Clearly, there is a potential for widespread
discrimination against those whose genes do not meet accepted
standards.

    Once someone's genes have been screened, the results could find
their way into computer banks. Without legal restrictions, these
personal revelations might eventually be shared among companies and
government agencies. Just like a credit rating or an arrest record,
a DNA analysis could become part of a person's permanent electronic
dossier. If that happens, one of the last vestiges of individual
privacy would disappear.

    Even if genetic information is kept private, the knowledge
gained can be profoundly troubling to the individuals involved. It
is one thing to uncover a genetic enzyme deficiency that can be
effectively treated through diet. But what about people who fear
they have inherited a debilitating disease for which there is yet
no treatment or cure? Some might want advance knowledge so they can
prepare their families and put what is left of their lives in
order. Others might prefer not knowing anything at all. "We may be
able to see into the future," says Doreen Markel, a genetic
counselor at the University of Michigan's Neurology Clinic. "But
ask yourself: Do you really want to know what you're going to die
of?"

    The questions multiply as the science progresses. Thomas
Murray, director of the Center for Biomedical Ethics at Case
Western Reserve University, acknowledges that some people are
worried that a complete map of the genome might somehow "diminish
our moral dignity . . . reduce us somehow to nothing more than the
chemical constituents of our bodies." But knowing the entire
sequence of DNA base pairs is like having the full musical notation
of Beethoven's Ninth Symphony, he says. "In no way does that
knowledge diminish the grandeur of the symphony itself."

    University of Washington ethicist Albert Jonsen is concerned
that people with grave illnesses might be viewed simply as carriers
of genetic traits. "Rather than saying `Isn't that family
unfortunate to have a schizophrenic son,' we'll say `That's a
schizophrenia family.' " Advocates for the handicapped fear that
in the future the physically afflicted may no longer be seen as
unfortunates worthy of special treatment, but as "wrongful births,"
genetic errors committed by parents who failed to take proper
action against a defective gene.

    To speak in terms of eliminating genetic defects is to tread
on slippery scientific and ethical ground. As any biologist will
testify, genetic variety is the spice of life, a necessary
ingredient to the survival of a species. Genes that are detrimental
under certain conditions may turn out to have hidden benefits.
Sickle-cell anemia, for example, is a debilitating blood disease
suffered by people of African descent who have two copies of an
abnormal gene. A person who has only one copy of the gene, however,
will not be stricken with anemia and will in fact have an unusual
resistance to malaria. That is why the gene remains common in
African populations.

    Even to label genes as defective can be dangerous. In the 19th
century new discoveries about heredity and evolution gave rise to
the eugenics movement -- a misguided pseudo science whose followers
thought that undesirable traits should be systematically purged
from the human gene pool. Believers ranged from the American
eugenicists of the early 1900s, who thought humans should be bred
like racehorses, to the German geneticists who gave scientific
advice to the leaders of the Third Reich, instructing them on how
the species might be "purified" by selective breeding and by
exterminating whole races at a time.

    No geneticist today would even talk about creating a master
race. Scientists are careful to point out that experiments in gene
therapy will be aimed at curing hereditary disease and relieving
human suffering, not at producing some sort of superman. But what
if people want to use the technology to improve genes that are not
defective but merely mediocre? Could genetic engineering become the
cosmetic surgery of the next century? Will children who have not
had their genes altered be discriminated against?

    Scientists agree that it would be reprehensible to try to move
too far in the direction of genetic uniformity. "The improvement
and enhancement of genetics to some sort of optimum is not a
function of medicine," observes the University of Minnesota's
Caplan. "Very soon the medical fields are going to have to state
clearly that their primary goal is the elimination and cure of
disease and disability."

    The possibilities for gene therapy will be limited for the near
future. If gene transplants are performed on tissue cells --
bone-marrow cells, for instance -- the altered genes will die with
the patient; they cannot be passed on to any children the patient
might subsequently have. Someday, however, it may be possible to
change genes in germ cells, which give rise to sperm or eggs. If
that feat is accomplished, the new genes would be transmitted to
one generation after another.

    That is what most frightens the foes of genetic engineering.
If biologists can change the course of heredity, they can try to
play God and influence human destiny. In 1983 activist Jeremy
Rifkin, a longtime opponent of many kinds of genetic research, and
several dozen theologians mounted an unsuccessful effort to
persuade Congress to ban all experiments on human germ cells. Said
Avery Post, president of the United Church of Christ, at the time:
"We're not good enough or responsible enough. There is no question
about it. We will abuse this power."

    No geneticist is currently planning to transfer genes to human
germ cells. Even though mankind has been playing God since biblical
times, rearranging the germ lines of crops and farm animals to suit
human needs, researchers do not advocate extending such genetic
tinkering to people. But medical scientists have an obligation to
protect humanity against disease and pestilence. Once it becomes
possible to eradicate a gene that causes a fatal disorder, and thus
keep it from passing to future generations, it will be criminal not
to do so. As director of the Human Genome Project, James Watson
contends that the research has a crucial humanitarian mission. Says
he: "The object should not be to get genetic information per se,
but to improve life through genetic information."

    Fortunately, the most ardent supporters of genetic research are
the first to admit the potential for abuse and see the need for
ground rules. Many ethicists and scientists who have studied the
issues agree on certain basic principles:

    Individuals should not be required to submit to genetic testing
against their will.

    Information about people's genetic constitution should be used
only to inform and never to harm.

    The results of a genetic assay should be held in strict
confidence.

    Genetic engineering in humans should be used to treat diseases,
not to foster genetic uniformity.

    Knowledge is power, the saying goes. It can be dangerous, but
it can just as easily be used wisely. "I do have faith," says Case
Western's Murray. "Not that the judgment of people is always right,
but that eventually we will preserve a good measure of fairness and
justice. If we can absorb Copernicus and Galileo, if we can absorb
Darwin and Freud, we can certainly absorb mapping the human
genome."

    One thing is certain: the genie cannot be put back into the
bottle. Like atomic energy, genetic engineering is an irresistible
force that will not be wished or legislated away. The task ahead
is to channel that force into directions that save lives but
preserve humanity's rich genetic heritage.