Genomics: implications for toxicology.

The primary goal of the Environmental Genome Project (EGP) is the identification of human polymorphisms indicative of susceptibility to specific environmental agents. Despite evidence for a substantial genetic contribution to disease variation in the population, progress towards identifying specific genes has been slow. To date, most of the advances in our understanding of human diseases has come from genetic analyses of monogenic diseases that affect a relatively small portion of the population. The principal strategy of the EGP involves resequencing DNA samples from populations representative of the US racial and ethnic groups to develop a database of variations. Polymorphisms in specific genes may also be detected by gene-expression profiling. The identification of polymorphisms by resequencing is straightforward, and can be accomplished with minimal difficulty. Gene-expression profiling is still problematic; however, determining the functional significance of the allelic variations will be a monumental challenge involving sophisticated proteomics and population-based and animal model studies. These studies will change radically the practice of public health and clinical medicine, and the approach to the development of pharmaceuticals.