hile much of ELSI research has been driven by concerns about the human rights of individuals and their families in the context of genetic testing for single-gene disorders with relatively high penetrance (e.g., mutations conferring cancer predisposition), the interface between ELSI and public health practice (or PHELSI) leads to a set of concerns that are somewhat different from the traditional clinical practice involving genetic testing and counseling of high-risk families (Table 6). Section V addresses some but not all of these issues, including the interface between public health and the law (chapter 25), the informed consent process in traditional public health genetics programs (chapter 26), and issues surrounding public health surveillance and information systems (chapter 27). At this time, many of these issues are unresolved. Public health leadership is needed be ensure discussion of sensitive issues and consensus building that balances individual rights with societal concerns, and they highlight an urgent need for population-based epidemiologic research.
One issue that has received a lot of attention over the past decade is the informed consent process for using stored genetic research tissue samples (50-2). In a public health setting, stored samples from large-scale national surveys or newborn blood spots could be used to conduct human genome epidemiologic studies for evaluating the impact of genetic variation on the burden of disease in the population. Although there is universal agreement on the need to obtain informed consent from subjects participating in genetic research, opinions differ regarding the use of stored samples from population surveys for which there is no or inadequate informed consent. There has been debate about the practicality of recontacting subjects from population studies; whether or not genetic studies pose more than "minimal risks" to subjects; the definitions and desirability of "anonymization" of existing samples; and whether or not coded but "linked" or "linkable" samples can be used (e.g., 50) (Table 6).
In these discussions, a distinction has been made between allelic variants that have high penetrance or risk for disease and the more common genetic variants (e.g., blood groups, HLA antigens, variants in drug metabolizing enzymes) that are neither necessary nor sufficient for disease development (50, 53-5). The latter group of genetic variants are risk factors that act in combination with other genes and environmental factors and are often associated with low relative risks for disease; however, in most existing recommendations and guidelines put out by various groups, the distinction between the two types of genetic variation has not been considered, perhaps implying that all genetic testing should be treated the same with respect to potential harm to individuals. Currently, the National Bioethics Advisory Commission, appointed by the President of the United States, has deliberated on genetic research on stored tissue samples (56). As recommendations on informed consent issues are developed by various groups, it is obvious that public health officials and researchers need to work with clinicians, ethicists, social scientists, lawyers, consumers and other groups, and to participate through individual action and through professional organizations, in defining and resolving these issues for public health practice.
III. Education and Training
The rapid expansion of the field of human genetics strains the ability of public health researchers, health practitioners, policy makers, and consumers to keep abreast of new information and its potential ramifications for policy, research and practice; therefore, concerted efforts are needed to provide various audiences, especially public health professionals, with the knowledge and skills they need to integrate genetics into public health activities. This emphasis on training public health professionals is exemplified by ongoing CDC training activities (57) as well as the development of several genetics training programs in various U.S. school