Designing Our Descendants: The Promises and Perils of Genetic Modifications

1 Framing the Issues

c h a p t e r o n e Framing the Issues Audrey R. Chapman, Ph.D., and Mark S. Frankel, Ph.D. Typically, our society proceeds in a “reactionary mode,” scrambling to match our values and policy to scientific developments. But doing so has serious limitations . The furor over the possibility of applying somatic cell nuclear transfer technology to clone human beings underscores how difficult it is to undertake a serious examination of the ethical, religious, and societal implications of new technologies after scientific breakthroughs have already been made. Thus, when confronted with a potential scientific advance that raises profound issues related to the possibilities of modifying our genetic futures, it is important to plan ahead, to decide whether and how to proceed with its development, and to give direction to this technology through rigorous analysis and public dialogue .This volume explores the feasibility and implications of proceeding with one such potential innovation,inheritable genetic modifications (IGM),which would confer the ability to design our genetic futures. Rapid breakthroughs in genetic research spurred by the Human Genome Project, advances in molecular biology, and new reproductive technologies have advanced our understanding of how we might approach genetic interventions as possible remedies for diseases caused by genetic disorders, partic- ularly for those caused by abnormalities in single genes. Limitations of current medical therapies to treat diseases with a genetic component have led to efforts to develop techniques for treating diseases at the molecular level, by altering a person’s cells. To date, most of the research and clinical resources related to gene therapy have been invested in developing techniques for targeting nonreproductive body cells.Somatic gene therapies are intended to treat or eliminate disease only in the individuals receiving treatment. After many years of frustration in attempting to produce techniques for efficient gene transfer of somatic cells, in 2000 clinical scientists published evidence of credible successes in improving the health of patients with two diseases—hemophilia B and X-linked immunodeficiency—through gene transfer, perhaps signaling that years of research are about to bear fruit.1 Recent advances in animal research are raising the possibility that we will also eventually have the technical capacity to modify genes that are transmitted to future generations.2 This volume uses the terminology of IGM to refer to any biomedical intervention that can be expected to modify the genome that a person can transfer to his or her offspring. Earlier literature identified these interventions as “germ-line therapy.” One form of IGM would be to alter the germ or reproductive cells that develop into the egg or sperm of a developing organism and transmit its heritable characteristics. Another form of IGM would be to modify the embryo itself. Still other technologies under development , such as the insertion of artificial chromosomes, could also be used to introduce inheritable genetic changes. In theory, the ability to undertake inheritable genetic modifications could have several advantages over somatic cell gene therapy. IGM offers the possibility of preventing the inheritance of some genetically based diseases within families rather than repeating somatic therapy generation after generation. Because these interventions could influence the earliest stage of human development , the technology also offers the potential for preventing irreversible damage attributable to defective genes before it occurs.Some scientists and ethicists argue that germ-line intervention is medically necessary to prevent certain classes of disorders because there are situations where screening and selection procedures will not be applicable, such as when both parents have the same mutation.3 Over a long period of time, germ-line gene modification could be used to decrease the incidence of certain inherited diseases in the human gene pool currently causing great suffering.4 IGM, however, also raises profound ethical, theological, and policy issues 4 Audrey R. Chapman and Mark S. Frankel that need to be thoroughly explored, discussed, and evaluated before further work in this area proceeds. Efforts to modify genes that are transmitted to future generations have the potential to bring about not only a medical but also a social revolution, for they offer us the potential power to mold our children in a variety of novel ways through genetic enhancement. These techniques could confer extraordinary control over biological properties and personality traits that we currently consider essential to our humanness. Even with the technical...