The SNP-based p-values derived from the meta-analyses were applied to gene-based association testing using KGG software (http://statgenpro.psychiatry.hku.hk/limx/kgg/) (23). No prioritization or preselection of genes was performed. Gene-based tests in KGG combine univariate association statistics to evaluate the cumulative evidence of association in a gene using extended Simes test (GATES) (24). SNPs were mapped onto 23 931 genes according to the gene coordinate information from NCBI, and SNPs within 10-kb of each gene were assigned to that gene. We considered genes with P<2×10−6 (=.05/23 931) as significant and those with q-value <0.1 as interesting (25).
