By sometime this summer, scientists in government and privately funded laboratories working under the auspices of the international Human Genome Project (HGP) will have sequenced all 3 billion letters of the human genetic code and the 50,000 to 100,000 human genes (functional units) that these letters make up. Within a year, the entire sequence will be available to any researcher on the Web or on a DVD disk.
With that information, an astonishing new era in biology and medicine will open. By correlating human DNA sequences (genotype) with their observable biological expressions (phenotype), researchers will be able to understand the genetic bases of many human disease conditions. A full knowledge of the genotype will also open new areas of historical investigation in the history of human population movements, ethnic diversity and the genetic bases of many human characteristics.
Almost as astonishing as this scientific achievement are the ethical questions it will raise for us. I think it is certain that those who live in the 21st century will constantly wrestle with new issues and challenges posed by the HGP's findings. In particular, I would signal four major areas where we will be challenged by genetic research.
Gap between diagnosis and cure
A major goal of the human genome project is to help us provide new medications or therapies for diseases in which genes play a part. For example, the terrible lung disorder cystic fibrosis, which causes the premature death of many young people in our country, is caused by the misspelling of a single letter in a gene that makes an essential product for salt transport in the lungs. By better understanding the genetic bases of these diseases, we might be able to produce drugs that do the body's work. Another hope is that we might be able to use gene therapy to correct the misspelled genes and cure the disease at its source.
The ethical challenge posed by this information is that there usually is a time lag between discovery of the genetic basis of a disease and its cure. Although the gene for cystic fibrosis was discovered more than a decade ago, no cures have yet resulted. When genetic information points to serious problems ahead, with no available cure or therapy, the question arises of whether that information is really beneficial. It is possible now to genetically diagnose some forms of inherited breast cancer. But because few therapies are available, a woman who receives this diagnosis can often do little except worry. Preventative bilateral mastectomy is an option, but since the genetic diagnosis is uncertain, this poses a terrible choice.
Nancy Wexler has put the problem succinctly. Her family suffers from Huntington's Disease, a severe neurodegenerative disorder that only starts in one's 40s or 50s and invariably leads to death. Although the gene for HD was discovered a decade ago, there is still no cure. Wexler and others wonder whether anybody really needs genetic information of this sort. Do you want to know you are going to have a terrible -- and unstoppable -- death? In Wexler's words, "We can see the flood but we cannot stop the tide."
Risks of Genetic Discrimination
The risks of genetic information are not just psychological. Many fear that in the future insurers, employers, and even educational institutions will use genetic information to discriminate. Insurers argue that by using genetic information they could reduce their costs. Why not add extra charges for health insurance, or even deny it entirely, to someone who has a higher than normal genetic risk of prostate cancer or heart disease? This raises a prospect depicted in the film "Gattaca," where genetic testing becomes a requirement at every phase of life, from pre-school through employment. To many, including myself, this is a nightmare scenario. But the question is, how do we build the arguments and policies that such uses of genetic information are unfair and unwise?
New Reproductive Choices
It is already possible to do many prenatal tests for genetically related conditions like Downs Syndrome or Tay-Sachs disease. As the HGP expands our genetic knowledge, the number of tests will proliferate, and spill over from disorders like these to many non-disease qualities. Which tests should be on parents' "menu" of choices? Greater resistance to disease? A tendency to obesity? Height? IQ? Sexual orientation? All may be possibilities in the not-too-distant future. The questions here are both personal and social. Do we really want parents engaged in a genetic race to have the tallest basketball-playing youngsters or the fastest runners? Do we want the quest for admission to Dartmouth to start with mom and dad's choices at the assisted reproductive clinic?
"Playing at God"
A final set of questions concerns how far human beings should go in manipulating the genetic bases of our lives. Do we really possess enough knowledge and ethical wisdom to take into our own hands what amounts to the future evolution of our species? To some people, such control of human genetic destiny amounts to hubris, or, in religious terms, to an objectionable "playing at God." Others disagree, saying that human beings have always intervened to alter nature. Whichever side one takes in this debate, repeated questions arise as to how and where we will draw lines between allowable and prohibited interventions.
It has been said that wisdom is the knowledge of how to use knowledge. The Human Genome Project will furnish us with unprecedented knowledge of our own genetic make up. Can we develop the wisdom to use it?
