Gene expression studies and complex diseases

Abstract

Gene expression studies have become a widely used approach in biological research. Modern laboratory technologies make it now feasible to accurately characterize essentially the entire human transcriptome in a single experiment. Aided by the enormous progress in molecular biological techniques, the quantification of the expression levels of genes (and parts thereof) is now a routine part of many types of investigations. Some transcriptional profiling studies are designed to identify transcriptional correlates of disease, in order to gain insight into the etiology or pathophysiology of disease. Other gene expression studies are focused on understanding and characterizing the genetic regulation of gene expression itself. Transcriptome studies can also be used to examine the influence of the environment on human health and disease and to study drug response. And there are myriad of other scientific questions that can be addressed via the study of gene expression. Integrative genomic approaches, in which transcriptional profiling is combined with other high-dimensional, modern molecular information sources about how our genome and our cells function, are becoming increasingly important in the study of human health and disease. This chapter gives a short overview of gene expression studies, focusing on the big picture and key underlying assumptions rather than details of laboratory procedures or analytical minutiae.