Objective: Schizophrenia is a complex genetic disorder which likely involves many genes each producing a slight increase in risk. Finding weak-acting genes in complex genetic disorders has been challenging and will likely require a number of approaches and large clinical samples. Several strategies have emerged recently that appear to markedly improve the power of genetic studies for detecting such genes. These include using association (rather than linkage) and using intermediate phenotypes in addition to DMS-IV diagnosis.
Study Population: We propose to take advantage of these techniques by studying quantitative traits related to schizophrenia in patients, siblings, and controls.
Design: We will employ an association design, rather than linkage. Traits will include quantifiable neurobiological variables that have been implicated previously as possible phenotypes related to schizophrenia. These include tests of attention and cognition, and a variety of parameters using brain imaging and magnetoencephalography.
Outcome Measure: We will use several statistical methods to show that specific genetic polymorphisms affect these phenotypes, including case control and family based association studies.