'Any powerful technology comes with risks, and the more powerful the technology, the greater the risks.'? Dr. Francis S. Collins, director of the Human Genome Project
The Human Genome ? 'The Book of Life'
Scientists are close to decoding the human genome? The molecular instructions for human development and function. The results promise to change medicine and human lives in ways that are difficult even to comprehend.
The first goal is to compile a sequential list of each letter in the operating instruction
that are embedded within each of our cells.
Go to Genome Explained.
To the public, the effort has been portrayed as a race. The Human Genome Project, an international consortium of scientists backed by the U.S. government plods toward the finish line. Meanwhile, a late-starting private company, Celera Genomics Group, sprints forward? Some say recklessly.
The winner gets bragging rights, as did Charles Lindbergh when he became the first person to fly across the Atlantic Ocean. Dr. Francis S. Co;;ins, director of the Human Genome Project, has compared its work to the historic explorations of Lewis and Clark, Sir Edmund Hillary and Neil Armstrong.
Go to The Genome Race
But much more than a race is at stake here. In a broad sense, the winner should be the human race. "This may be one of the most pivotal moments in the history of life sciences," said Tony L. White, chairman and chief executive of PE Corp., as its Celera Genomics Group subsidiary cleared a milestone in decoding of the human genome.
As genetic knowledge explodes, scientists say it will open doors to fabulous prizes. It will enable people to live longer and healthier? though perhaps more more complicated? lives.
Physicians will cure some genetically linked diseases and find ways to counteract genetic predispositions to others. They hope to repair defective genes and fix or replace damaged organs with genetically engineered cells. Drugs and therapies will be individually tailored for maximum benefit.
Go to Medical Marvels
Yet such advanced will take decades, and as companies and scientists vie to patent findings on the location, use and function of genes, some scientists fear this leap forward could be grounded by a tangle of competing patent claims.
Go to Who Owns Human Genes?
And despite their promise, genetic insights also pose quandaries and risks. Genetic testing for many conditions arrives far ahead of cures. And genetic profiles could be used to discriminate against disease-prone people, or used to control reproduction and childbirth, to improve the gene pool.
Go to The discriminating Gene
What is the human genome?
Some call it the "Book of Life." Others the "Holy Grail of Biology."
It tell cells what to do, and when and where to do it. It dictates the production of proteins that the body needs to function and prosper, feed itself, fight off disease, and reproduce. It even carries code for instincts and emotions.
Physically, it is a string of chemicals in the nucleus of every living cell. In humans, these are arranged in the double-helix form in a molecule called deoxyribonucleic acid, or DNA. This structure, described less than 50 years ago, is represented in textbooks as a spiral staircase formation with hydrogen serving as rungs between two chains of compounds called nucleotides.
Like the computer, which is based on a simple code of zeros and ones, DNA builds enormously complex patterns out of a tiny range of building blocks.
The crucial nucleotide links in the chains on each side of the double helix are made of only four different nitrogenous bases: adenine, guanine, cytosine and thymine, or A,G,C and T. These are the full alphabet of the book of life. They make for monotonous reading,since the genome contains a nearly endless sequence of the same four letters. But their unfolding secrets engross the minds of genetic scientists.
Identifying the sequence of this code is only the first step toward understanding it. Change a tiny fraction of the bases and you change a human to an ape. Change less than 1 percent of base pairs, and you change one human into another. And miscoding of only a few bases can spell the difference between good health and illness, and perhaps early death.
John, a 23-year-old graduate, is encouraged to undergo genetic testing. His physician notes he has a high serum cholesterol level, which has long been linked to the risk of heart attack and stroke. In fact, heart attacks have been common in John's family; one killed his father at the age of 48.
John undergoes 15 genetic tests that probe his risk of diseases for which preventive strategies are known. He passes up 10 other tests for disorders that medicine hasn't yet learned to prevent or cure.
The tests come back with some good news. John's risk of prostate cancer and Alzheimer's disease are low.
The bad news, however, is that his genes expose him to a higher-than-normal risk of heart disease, colon cancer and lung cancer. If John is going to avoid his father's early death, he will need to take precautions.
Jonn's doctor prescribes a drug that will reduce his cholesterol level, and with it his risk of heart attack and stroke. John plans to undergo an annual colonoscopy beginning at age 45, inspection of the lower intestine that is a relatively cheap and easy way to catch colon cancer early.
And faced with evidence that his lung cancer risk is high, John makes a major life-style change. He has been smoking a pack of cigarettes a day for six years, which elevates his ling cancer risk. So he joins a support group of people who face high disease risks linked to smoking, and with the group's help, he kicks the addiction.
John is a hypothetical patient created by Dr. Francis Collins, director of the National institutes of Health's portion of the Human Genome Project, to illustrate how genetic testing might change medical practice by 2010.
Genetic testing already can detect risk factors for Parkinson's disease, cystic fibrosis, Huntington's disease and breast cancer, among other disorders. So far, most testing is focused on a mistake on a single gene. But to fulfill its promise, testing must evolve to a more complex task:to show how combinations of genes may contribute to a person's risk of disease.
And testing is just the beginning of the payoff expected from the swelling flood of genetic advances. The bright hope of genomics is that medical science will understand the mechanisms of life so well that it can devise precise treatments to stave off illness and improve the quality of life.
Completion of a human genome sequence, expected by 203, "will bring countless improvements in the early detection and treatment of disease and new approaches to disease and new approaches to disease prevention," says Dr. R. Rodney Howell, president of the American College of Medical Genetics.
"Once the basic genetic mechanism of disorder is understood, there is a far better chance of conquering the disease."
Already, more than 50 gene-based drugs have become available for use in the treatment of cancer, heart attack, stroke and diabetes, according to Dr. Collins of NIH. In coming decades, medicine will identify and cure many potential diseases at the molecular level, Collins says, even before they strike the patient.
Drugs and gene therapies will zero in on individual genes for precise cures with fewer side effects than most current therapies. Drugs, which often have different effects on different people, will be custom-designed to best suit the individual's genetic profile.
Computer models may well predict the effect of a drug or the toxicity of a substance. Already, scientists are experimenting with changing the genetic code of human cells using such delivery mechanisms as viruses, although the results have thus far been disappointing. And they are talking of building new human organs? Perhaps even outside of the body? to replace damaged ones.
Dr. William Hasetine, CEO of Human Genome Sciences, a genetic research and development firm in Rockville, Md., even talks of growing a new human hand outside of the body.
The average human life-span will reach 90-95 years, says Collins, and scientists will probe the molecular basis for extending it much further.
Genomic information will open up avenues to advance human knowledge in other fields as well. Already, DNA is being analyzed to link suspects to crimes. Anthropologists and evolutionary biologists will mine DNA sequences to better understand where species and races came from, and how.
But the main benefit is expected to be medical, and it is only beginning. Even though the human Genome Project is on the verge of completing a highly accurate sequence of the base pairs in the genome, decades of work lie ahead to discover the functions of about 80,000 human genes, says Dr. Collins.
"The genetic revolution in medicine," he says, "is under way."
But with al this promise, there are also huge social and ethical debates ahead.
For genetic counselor Wendy Uhlmann, the promise of modern medicine is tempered by fear.
Advances in genetic testing "hold great promise for surveillance and preventive treatments," she wrote recently in the New York Times. "yet also hold the potential for stigmatization and discrimination."
As scientists close in on the code for thousands of human genes, the number of disorders and risk factors that can be identified by genetic test is growing fast.
But so are fears that genetic test results will expose people at high risk of disease to discrimination in getting hired and fired, obtaining health and life insurance and even having children. One study showed 9 percent of respondents said they or their relatives declined genetic testing because of their fear of such discrimination.
Feb. 9, 2000, president Clinton signed an executive order that will bar federal agencies from requiring employees to submit to genetic tests or from using genetic test results in making employment or promotion decisions.
"My goal is to set an example and pose a challenge for every employer in America," the president said, "because I believe no employer should ever review your genetic records along with your resume."
According to Uhlmann, who works at the University of Michigan and is president of the National Society of Genetic Counselor, 23 states have passed law as barring employment discrimination based on genetic information. But the breadth of protection varies. Federal legislation has been proposed to extend such protections nationally.
For many people, their worst genetic nightmare is that DNA data could be used to justify public choices on who will have children. The study of human eugenics? the improvement of genetic stock? was once used to support sterilization of mentally impaired people in the United States, and ultimately to mass sterilization and death
camps in Hitler's Germany. At a more personal level, parents may decide to abort a fetus due to its genetic risk profile, or even its sex.
Tough quandaries also stem from discrimination in health and life insurance. Some fear that insurers will deny insurance or set a high premium for people with high-risk genetic backgrounds. While some people find this offensive, others defend it as consistent with the principle that insurance is designed to spread risks among people in the same pool.
If a man knows he faces high risk of heart attack, for example, he could buy heavy life insurance coverage without paying more for it than people at low risk. If common, this would force up premiums generally. Should his risk be shared with the
Many genetic experts say no, genetic profiles should be kept private. Among them is James Watson, who with Francis Crick discovered the structure of DNA in 1953 to launch genetic science into a brave, new world.
"I think that somehow we have to get it into the laws that anyone's DNA? the message it gives ? is confidential." Watson says.
The Human Genome: The Book of Life.
Scientists are close to decoding the human genome, the molecular instructions for human development and function. The results promise to change medicine and human lives in ways that are difficult even to comprehend. The first goal is to compile a sequential list of each letter in the operating instructions that are embedded within each of our cells. To the public, the effort has been portrayed as a race. The Human Genome Project, an international consortium of scientists backed by the U.S. government, plods toward the finish line. Meanwhile, a late-starting private company, Celera Genomics Group, sprints forward, some say recklessly. The winner gets bragging rights, as did Charles Lindebergh when he became the first person to fly across the Atlantic Ocean. Dr, Francis S. Collins, director of the Human Genome Project, has compared its work to the historic explorations of Lewis and Clark, Sir Edmund Hillary and Neil Armstrong. But much more than a race is at stake here. In a broad sense, the winner should be the human race. "This may be one of the most pivotal moments in the history of life sciences," Tony L. White, chairman and chief executive of PE Corp., told the Los Angeles Times. "It cleared a milestone in decoding of the human genome.
As genetic knowledge explodes, scientists say it will open doors to fabulous prizes. It will enable people to live longer and healthier, though perhaps more complicated lives. Physicians will cure some genetically linked diseases and find ways to counteract genetic predisposition to others. They hope to repair defective genes and fix or replace damaged organs with genetically engineered cells. Drugs and therapies will be individually tailored for maximum benefit. Yet such advances will take decades, and as companies and scientists vie to patent findings on the location, use and function of genes, some scientists fear this leap forward could be grounded by a tangle of competing patent claims. And despite their promise, genetic insights also pose quandaries and risks. Genetic testing for many conditions far ahead of cures. And genetic profiles could be used to discriminate against disease-prone people, or used to control reproduction and childbirth, to "improve" the gene pool.