TIME: Almanac 1993/TIME Almanac 1993.iso/time/101592/10159919.000

Text File | 1993-04-08 | 5.8 KB | 121 lines

                                                                                SPECIAL ISSUE: MILLENNIUM -- BEYOND THE YEAR 2000 

THE CENTURY AHEAD, Page 58

Seeking a Godlike Power


Genetic science promises to deliver the blueprint for human
life

BY LEON JAROFF


    Staring at the walls of doctors' offices while awaiting
their turn, 21st century Americans may see a colorful chart
hanging next to the traditional diplomas and the renderings of
skeletal parts and organs. It will depict the 23 pairs of human
chromosomes and pinpoint on each one the location of genes that
can predispose people to serious disease.

    By then, scientists involved in the $3 billion Human Genome
Project will have isolated and identified most or all of the
more than 100,000 genes crammed into the human genome, the
strand of DNA in the nucleus of each of the body's 100 trillion
cells (with the exception of red blood cells, which have no
nuclei). And scientists will have sequenced, or placed in
order, the 3 billion chemical code letters in that strand,
giving them the ability to read nature's complete blueprint for
creating a human being. As the project nears completion in the
first decade of the next century, knowledge flowing from it will
begin to have a major impact on medicine and other sciences,
industry, agriculture, law and the environment. The stage will
be set for an Age of Genetics that could rival the Industrial
Revolution in its impact on society.

    In 15 or 20 years, predicts biologist Leroy Hood of the
California Institute of Technology, doctors will be able to
take a blood sample from a newborn infant, extract DNA from the
blood and insert it into a machine that will analyze 100 or so
genes. "That will give us DNA fingerprints of genes that
predispose us to common kinds of diseases," Hood says. Based on
the genetic profile, the computer will dispense some medical
advice. It might say, "This individual has a tendency toward
skin cancer and should avoid overexposure to the sun." Or: "He
has insufficient LDL cholesterol receptors and a proclivity to
obesity, so he should begin a high-fiber, low-fat diet at age
3." Explains Mark Skolnick, a geneticist at the University of
Utah: "Once you can make a profile of a person's genetic
predisposition to disease, medicine will finally become largely
predictive and preventive." With the profusion of such profiles
will come a demand for, and laws enforcing, genetic privacy, to
ensure that those with potentially crippling or lethal genes
are not discriminated against by employers or insurers.

    Other contentious issues will arise. Doctors will be able
to detect many serious genetic diseases at the fetal stage,
which will lead some parents to opt for abortion. But there
will also be preventive measures for people who want to avoid
passing their defective genes on to their children. When one
parent carries the deadly and dominant gene for Huntington's
chorea, for example, there is a 50% chance that any offspring
will have it too. To reduce those odds to zero, doctors of the
future will extract several eggs from the prospective mother
and fertilize them in a test tube with her husband's sperm. When
the fertilized eggs have grown to the 32- or 64-cell stage, the
doctors will flick off a few cells from each and analyze their
DNA. When they find an egg carrying a gene without the fatal
defect, they will implant it in the uterus and allow the fetus
to grow to term, free from the threat of Huntington's disease.

    For those who do inherit a deadly gene or two, research
will provide drugs to alleviate the symptoms. The active
ingredient in these drugs will be protein mass-produced by
bacteria or by plants. In each case, healthy versions of the
genes that have gone awry in humans will be inserted into the
DNA of the producer. In the next several decades, the drug
treatment will be supplemented or replaced by genetic
engineering. Doctors will insert good genes into a patient's
DNA, where they will take over the function of defective ones
and actually cure the disorder. "The gene then codes for the
production of the missing protein," explains University of
Michigan geneticist Francis Collins, "and the protein is the
drug. What you're delivering is the instructions instead of the
product."

    Meanwhile, as public fears about genetic engineering fade,
agricultural scientists will be producing new and revolu
tionary plants. They have already inserted a variety of plant,
animal and human genes into potato and tobacco plants,
transporting the genes to their target in a bit of DNA from a
bacterium that naturally infects plant cells. These hybrid
plants now produce small quantities of natural polymers and
chemicals for industrial purposes, proteins for medical use and
enzymes for food processing. In the next few decades, they will
become factories of mass production.

    The next century will bring hundreds of genetically
engineered foods: disease-resistant fruits and vegetables with
longer shelf life, starchier potatoes, beans with more protein.
"We will come up with new varieties of low-fat, high-fiber
foods that taste good and that people really want to eat," says
Charles Cantor, principal scientist for the Energy Department's
branch of the genome project. Plant genetics will also help the
environment. Scientists envision placing genetically engineered
plants on either side of expressways to extract lead and
nitrous oxides from the air. Plants designed to absorb more
carbon dioxide could help stem the advance of the greenhouse
effect.

    All told, genetic technology will give humankind an almost
godlike power to improve its condition. It will be one of
society's major tasks in the 21st century to develop a moral
and ethical code to match, and help control, this awesome
ability.