To advocates and critics alike, the Human Genome Project will have an impact far beyond the diseases that it might help cure. Nobel Laureate Paul Berg, whose work on recombinant DNA* helped [1]（1. turn 2. launch 3. stifle) the biotechnology revolution, calls the genome map “a new beginning for biology.” Already the genes of organisms ranging from laboratory mice to the HIV virus are yielding never before revealed [2] (1. Clues 2. Directions 3. Dilemmas) about the mechanisms of living things.
“Genetics offers the best road to understanding disease at this time,” says David Botstein, chair of genetics at Stanford and a national leader in the field. We can ask: Which genes predispose a person to this disease, what are the factors that work with the gene to cause the disease, and what can you do about it?”
In the next century, “instead of mass medicine, we’ll wave custom medicine, Botstein says. A drop of blood on a multiple-gene-testing silicon chip will be enough to tell your doctor whether you have a special risk of heart disease or diabetes or several different types of cancer. Prevention will keep high-risk people healthy and lower the overall cost of healthcare. Treatment will be tailored to match the individual’s genetic profile.
It is exactly that individualized gene profile that makes even [3] (1. opportunists 2. pessimists 3. enthusiasts) of the genome project wary.
Gene tests long have been used in prenatal* testing. But the next generation of tests will [4]1. Touch 2. Cover 3. Treat) many more lives. Geneticists disagree about how much a genetic profile can show, but to an individual it will read like the chart of her lifeline — her chances of developing asthma in childhood, the risk of getting breast cancer in her 40s, or the odds of suffering from Alzheimer’s in old age.
This is intimate knowledge, a biography in advance, not just of the individual but of her family. How do we interpret that information? How do we ensure that it doesn’t fall into the wrong hands? Do we really want to know this much about ourselves?
When scientists offer a powerful new technology, “they are making policy in our Society,” Joan Fujimura, an anthropologist at Stanford University, says. “When I talk to scientists, they don’t always see that.” Fujimura says even highly influential scientists often see their role as narrowly focused on finding out how nature works, while others in society think of the effect. “Biologists are producing the technology that will [5] (1. shape 2. twist 3. capture) our future,” she says. “It is important for them to think about the culture that will use their technology, what kind of society we want to have.”
David Botstein says, “these are social issues, not scientific issues.”
That sounds like a scientists [6] (1. dilemma 2. cliché 3. fear). But Botstein, an originator of some of the major concepts that made the genome project practical, is no ivory tower researcher. He questions, “How much can we hope to learn about the interactions of genetics and the environment? Will we actually be able to predict anything by knowing genes? The more thoughtful ones, very quickly, get into the issues of the limits of knowledge.”
Those limits — simply practical realities — will prevent most of the outrages that people worry about when they imagine the Brave New World of genomics, Botstein says. He tells people to forget [7] (1. brand-name 2. designer 3. master) babies or an engineered human race: It will be mathematically impossible to tinker with enough of our 80,000gene inheritance to design a “perfect” baby, let alone a “master race.”
Botstein does worry about healthcare discrimination, [8] (1. giving 2. making 3. calling) it a serious social problem. But he points out that it is mostly a problem in the United States — in Europe, there is [9] (1. some 2. little 3. a little) incentive to discriminate because everyone is guaranteed some level of healthcare. Paul Billings, deputy chief of staff at the Veterans Affairs Medical Center in Palo Alto, says that people like Botstein are [10] (1.deluding 2. cheating 3. camouflaging) themselves if they think that healthcare is the only arena where genetic information is misused. He cites a number of nightmarish cases: The 24year old woman fired from her job after her employer learned of her risk of Huntington’s disease, an ailment that usually doesn’t strike until after 40; their recruits turned down by the Air Force because they were [11] (1. carriers 2. patients 3. agents) of sickle cell disease; the two Marines court-martialed for refusing to take a gene test.
Billings has become a forceful advocate for the “asymptomatic ill”— healthy people with only a statistical risk of developing a disease. In a study published in January, he and his colleagues documented 455 cases in which people were [12](1. offered 2. sold 3. denied) insurance or healthcare — as well as jobs, schooling and the right to adopt children — on the basis of a family history of genetic disease. Billings and his coauthors say these people are the first members of a new social underclass.
“The genie is out of the bottle,” Billings says. “Every risk assessment event could be linked to gene tests: your driver’s license, gun permit, home mortgage.”
David Cox has a counter to that argument. “That genie has been out of the bottle for a long time,” he says. “If we got rid of genetics today, we would not be at a loss for ways to [13]1. Justify 2. Classify 3. antagonize) people and create social inequities.”
Like Billings, Cox has stepped outside the laboratory to try to influence the way that gene technologies are used. He is both a scientific leader of the national Human Genome Project and [14] (1. an establishing 2. a founding 3. an advocating) member of its unique spinoff: the Ethical, Legal and Social Implications (ELSI) Working Group.
“The idea was to have preemptive discussions,” Cox says. “To consider the effects of this technology before it happens so we won’t constantly have to clean up spilt milk.” In July, President Clinton [15] (1. admitted 2. appointed 3. adapted) Cox to a new National Bioethics Advisory Commission.
Cox says that what he’s learned in the ELSI process has taught him to be cautious about how much those achievements mean. “You don’t legislate away discrimination,” he says. “You just make it more painful for people to discriminate. It [16] (1. takes 2. gives 3. makes) a social belief that discrimination on the basis of genetic information is bad.”
If there is one thing Cox would like to tell people about genes, it is: “It’s genetic” doesn’t mean “it’s [17] (1. inevitable 2. indispensable 3. incalculable).” In fact, Cox says that modern genetic discoveries are changing some of geneticists’ own beliefs about predictability. The more they learn, the more they find that our genes are not complete predictors of destiny.
Cystic fibrosis, America’s most common fatal inherited disease, is a good example. [18](1. after 2. When 3. Before) the gene was discovered, doctors assumed they could predict the fate of any child carrying the mutated CF gene: a lifetime of serious illness, and a 5050 chance of dying before 30.
The isolation of the gene in 1989 changed those assumptions. As geneticists had expected, CF is caused by mutations on a single gene. Most children born with the mutated gene do suffer from its life-threatening effects. However, gene tests have now revealed people in CF families with the same mutations and almost no Symptoms.
The findings have changed the attitudes of many people with a family history of this disease. Doctors had predicted a big demand for the CF gene test. Instead, many people have opted not to learn if they are carriers of the mutated gene. Some have decided against the prenatal test for CF. The hope — not always realized — is that an afflicted baby’s symptoms will be mild.
The lesson, geneticists say, is this: Even for a disorder strongly influenced by a single gene, more than one factor influences the way the gene is expressed. The outcome depends on interactions with other genes, with hormones inside the cell, and with myriad environmental influences.
Those are just the complexities for the few hundred diseases, like cystic fibrosis and sickle cell anemia, that are [19](1. unintentionally 2. unreasonably 3. unquestionably) caused by genes. Much of the research linking genes to traits like obesity or alcoholism is preliminary, based on only a few human subjects — and still on shaky scientific ground, Cox and Billings say.
Some geneticists now doubt whether gene tests will be [20] (1. sensitive 2. Sensuous 3. Sensory) risk detectors after all. The comprehensive gene profile may not be the fortune-teller people imagined.
“Assuming that a genetic mutation means someone has a disease is naive genetic determinism,” medical ethicist Barbara Koenig says.
To the scientists, the genome project is akin to building a national highway system, an infrastructure for the hoped-for cures and the unexpected discoveries that will come later. They know that the pace of those discoveries will be uneven and unpredictable — that’s the way science usually works.
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