Single nucleotide polymorphisms and their characterization with oligonucleotide microarrays.

Small variations in human DNA sequences influence our predisposition to disease and our response to medications. Many psychiatric diseases appear to be polygenic. Because our molecular understanding of the genetic etiology of neuropsychiatric disorders is very limited, the discovery and characterization of these variations is crucial in identifying disease genes. Furthermore, this knowledge may enable the customized selection of drug treatments based on an individual's genotype so as to maximize efficacy yet avoid adverse side effects. Examples of findings using conventional methods for determining genotypes, as well as new and future technologies for the characterization of single nucleotide polymorphisms, will be discussed, with a focus on psychiatric diseases and medications.