We first explored the set of hypothesis-driven candidate genes using a variety of descriptive approaches (SAS Institute Inc., 2004, 2005). Quanto was used for power calculations (Gauderman and Morrison, 2006, Gauderman, 2002). We used DAVID (Dennis et al., 2003, Huang da et al., 2009, Sherman et al., 2007) to characterize hypotheses about the pathophysiology of schizophrenia reflected in the hypothesis-driven candidate gene list. DAVID identifies Gene Ontology biological pathways (Harris et al., 2004) with chance-corrected over-representation a given gene list. To account for overlap between pathways, we used the annotation cluster feature in DAVID to focus on higher-level clusters of similar biological processes.
