Introduction
Imagine you're playing a board game called GENES-R-US. You roll the dice and pick a card. It says: You're a 29-year-old pregnant woman. You've just been told you have a gene that almost always causes breast cancer in early adulthood. Your daughter-to-be has inherited this gene. Do you:
A) Abort the fetus to avoid a disease that won't strike for decades?
B) Carry the pregnancy to term and hope your daughter will not develop cancer until a cure has been found?
If you think such a scenario is science fiction, think again.
In the 1990s, researchers isolated the long-sought gene responsible for two inherited forms of breast cancer. The flawed versions of this gene, dubbed BRCA1 and BRCA2, are thought to put women at extraordinarily high risk of developing breast cancer. In 2005, it was announced that British women undergoing in-vitro fertilization would soon have the option of selecting embryos to implant based on whether or not they contain the flawed gene. This process is known as pre-implantation genetic diagnosis, or PGD. It's already used to screen for cystic fibrosis, haemophilia, Huntingdon's disease and Duchenne muscular dystrophy.[1]
As geneticists bag their quarry with increasing speed, unresolved medical and ethical issues continue to surface. Society has yet to settle, or in some cases even address, the complex questions that abound in this brave new world. And the road ahead surely contains many more conundrums created by newfound knowledge.
The virtual explosion in genetics research during the last 20 years has led to the identification of not one, but two human genomes -- male and female -- and genes that underlie heart disease, colon cancer, cystic fibrosis, Duchenne muscular dystrophy, Huntington's disease, and most recently, Parkinson's disease, as well as a variety of other ailments that have plagued human beings for millennia. Researchers around the world continue their feverish hunt for other elusive disease-causing genes.[2]
Such advances bring many tangible benefits to society and to people who suffer from genetic disorders. For example, the discovery of the malfunctioning cystic fibrosis (CF) gene led to the identification of a protein that produces the abnormally thick mucus that clogs the lungs of people with this disorder. Researchers have used that information to fashion new therapies for this disorder.
Recently, researchers took a historic first step by inserting a healthy version of the CF gene into the lung of a patient with cystic fibrosis. This process is known as genetic enhancement.
These examples represent a new frontier in genetic discoveries. The Human Genome Project, completed in 2003, charted the estimated 100,000 genes that orchestrate human life. This ambitious undertaking means that people of the future may obtain a computerized printout of their genetic code. Couples in such a world may ask for -- and get -- a detailed DNA profile of an embryo floating in a petri dish.
Such knowledge can prove potent. Insurance companies may refuse to offer coverage to a healthy infant whose DNA foretells a heart attack 40 years later. Indeed, some of the thorny aspects of genetic testing have already surfaced. Geneticists offer a blood test for Huntington's disease, yet this illness has no cure. Thus, people who opt for the test may spend years waiting for the first signs of their deterioration.
Scientists and ethicists routinely discuss the ethical difficulties raised by the project to map the human genome. Yet such discourse must move out of the realm of academia. Society must weigh in on the debate, as it touches nearly every aspect of what it will mean to be human in the 21st century.
What do you think? Take the interactive poll and see how you would react to some of these real-life ethical dilemmas.
Each summer, at the Short Course in Medical and Experimental Mammalian Genetics held at The Jackson Laboratory in Bar Harbor, Maine, researchers meet to discuss scenarios that illustrate the many facets of genetic counseling.
Article and poll adapted from Fackelmann, Kathy A. "Beyond the Genome: The Ethics of DNA Testing," Science News Online, November 5, 1994.
1Henderson, Mark. "How embryo screening may be the new way to beat cancer." The (London) Times, November 4, 2004.
2Connor, Steve, "War of the sexes: How chromosome study shows male and female genetic differences." The Belfast Telegraph, March 17, 2005.
2Carroll, Linda, "Parkinson's Research Focuses on Links to Genes and Toxins" New York Times, February 10, 2004