The first of these used a sample of 178 cases and 144 controls, assessed 500K SNPs and reported one experiment-wide significant association at rs4129148 (P= 3.7×10−7) in the X/Y pseudoautosomal region near the CSF2RA and IL3R genes21. Cytokines have been suggested as possible candidate genes previously, and one replication attempt supported association in IL3R24. The second used the CATIE25 sample of 738 cases and 733 controls and reported no genomewide significant results in stage 1 analysis22. The third used a multi-stage design of discovery in a newly genotyped sample of 479 cases compared with existing data from the 2937 UK controls used in the Wellcome Trust Case/Control Consortium studies26 and targeted replication in 6666 cases and 9897 controls. This study reported consistent evidence of association with 1 SNP in the zinc-finger protein ZNF804A gene23. Although the discovery sample in this study was modest, it is drawn from an Anglo-Celtic population (from Wales and the UK) broadly similar to the population from which we have sampled cases and controls (from Ireland and Northern Ireland) and the total sample size was substantial
