A first episode psychosis case-control genetic association study

Background:GAP(genesandpsychosis) is a case-control studyof firstepisode psychosis conducted in London and Cambridge, which aims toidentify genes conferring susceptibility to psychosis, and associatedphenotypes including cognitive dysfunction and cerebral morphology.Methods:First episode psychosis cases have been recruited in SouthLondon and Maudsley NHS Trust and in Cambridge. A variety ofdemographic and clinical data have been collected. In a subset of these,neurocognitive assessments and MRIs have been performed. Sampleshave been taken for DNA, and in a subset for RNA and proteomicanalysis. Genetic association analysis is being undertaken using acandidate gene approach. The genes chosen for the first wave ofanalysis include the current most promising candidates for suscept-ibility to psychosis (NRG1, dysbindin, DISC1, G72, etc) as well ascandidates for susceptibility to cannabis misuse (COMT), cognitivedysfunction, dysregulation of brain morphology or susceptibility tobipolar disorder (e.g. LIS1), and candidates in the dopamine andserotonin neurotransmitter systems.Results:DNA has been collected from 302 patients to date. Of these,72%aremale, and themeanage is 25 years; 187 areCaucasian; 115 areof black origin; and the rest are of other ormixed ethnicity. Genotypingis being undertaken in this sample and in matched controls.Conclusions:Data is being reported separately for a number ofphenotypes forwhich there is already somedata. This presentationwillreport the overall genetic association results.