Genetic and Epigenetic Determinants of Environmental Injury and Disease

Genomic diversity affects gene and protein expression profiles as well as cellular functions, and modulates the individual response to environmental stimuli. With an increasingly high exposure to xenobiotics as early as during embryo development, humans are at risk of developing toxicant-related diseases at younger ages. Genetic toxicology makes use of genetic, molecular, and physiological approaches to understand the relationship between genetic makeup, the biological response to xenobiotics, and the onset of disease. This article provides an overview of studies on genetic diversity, the mechanisms that have contributed to such diversity, and the influence of repetitive sequences in shaping the human genome. Also, a section was devoted to introduce the field of epigenetics and to understand the relationship between chromatin structure and responses to environmental injury. Overall, understanding how genetic profiles, the xenobiotic detoxification machinery, and chromatin structure modulate the physiological response to toxic injury is essential both for early diagnostics of genetic risks and for implementation of preventive measures to avoid early-onset disease. In addition, by forecasting the expected cellular response to drugs, genetic profile analysis will emerge as a useful means to target the treatment of human diseases.