Pharmacogenomics of schizophrenia

The genetic landscape is marked with several milestone achievements, from the early advances that elucidated DNA structure to the more recent completion of international scientific research projects, the Human Genome Project (HGP) and the HapMap project. These projects have enabled the availability of complete sequence of human genome and the sequence variation data between individuals. Although intensive polymorphism maps have been generated lately, the fact that genetic variations could be related to alterations in drug metabolism was recognized as early as 1950s (Motulsky, 1957). The term "Pharmacogenetics" was coined by Friedrich Vogel in 1959 to describe the role of genetic variation affecting drug response or adverse effects (Vogel, 1959). However, pharmacogenetic studies were limited to single gene variations, which seldom explained the complex phenomenon of drug response. With the advent of advanced high throughput technologies, the field of pharmacogenetics has graduated to "pharmacogenomics", with long term goal of understanding the drug action associated with genome and its products (Evans and Relling, 1999; Goldstein et al., 2003). Pharmacogenomics is emerging as an interdisciplinary area comprising of numerous domains such as medicine, genomics, informatics, cell and molecular biology, statistics and pharmacology (Hopkins et al., 2006). Advancing technology in genomics and our increasing knowledge of the functional consequences of genetic variations hold the promise to provide a basis for improved treatment of the clinical symptoms of complex disorders. The significance of such studies for optimizing drug therapies is immense, especially for therapeutics such as antipsychotic treatments, which are a major cost-burden on healthcare system owing to the long term therapeutic treatment requirements.