12 markers showed strong evidence for replication (p ≤ 5 × 10−4). However, their best supported variant failed to achieve the level of genome-wide significance (Table 1). The highest ranking SNP from this study is located in an intron of the zinc finger protein 804A gene (ZNF804A), a putative transcription factor. This had been neither investigated nor implicated in the risk for schizophrenia. The case sample was then extended to include bipolar patients and the p-value for the total sample of major psychosis patients surpassed the level of genome-wide significance (p = 9 × 10−9). The International Schizophrenia Consortium (2009) has subsequently replicated the association between ZNF804A and schizophrenia, and ZNF804A is therefore a promising true susceptibility gene for schizophrenia. Need et al. (2009) performed an initial GWA study of 871 schizophrenia patients and 863 controls and then followed up their best hits in a replication sample of 1460 cases and 12,995 controls. However, they failed to detect any association signal that could withstand correction for multiple testing.
