Genetic susceptibility testing, present and future

The variation in individual responses to environmental agents has been shown to be exceptionally wide. This variation is accounted for by differences in metabolic capacity (polymorphisms in drug-metabolizing or detoxifying enzymes), DNA repair capacity, or genetic predisposition to specific diseases. It is because of this large diversity of responsiveness to environmental toxicants that risks to chemical carcinogens have been difficult to pinpoint, particularly at low exposures. Opportunities now exist for studies of genetic susceptibility for cancer and other diseases in which an environmental component can be presumed. By using this technology to identify particularly susceptible subgroups, we will be able to better identify environmental risk factors for many diseases and to understand the mechanisms leading to these diseases. This raises some important ethical questions discussed elsewhere in this issue. This paper briefly discusses the state-of-the-art of the genetic screening tests and their anticipated future.