We performed an inverse-variance weighted, fixed-effects meta-analysis with all discovery GWAS data including approximately 6.5M common SNPs after applying post-imputation QC to each study. The genomic inflation factor λ ranged from 0.990 to 1.038 for all studies. The Q-Q plots of the meta-analyses for the CC and FS phenotypes are presented in Figure 1. Meta-analytic inflation factors were 1.03 and 1.02, suggesting little effect of population stratification. Manhattan plots are presented in Figure 2. Table 2 lists the LD-independent, genome-wide significant SNPs and associated regions. For the CC model, the strongest association was observed at rs1709393 located in an intron of an uncharacterized non-coding RNA locus LOC152225 on chromosome 3q12.3 (P=1.65×10−8; Q=0.027). Allelic frequencies were very similar across studies and ranged between 0.55 and 0.60. The most significant SNP in the FS model was rs1067327 on chromosome 2p21 within CAMKMT encoding the calmodulin-lysine N-methyltransferase (P=2.86×10−9; Q=0.0017) with LD extending into several adjacent genes. Allelic frequencies were consistent across studies, ranging from 0.32 to 0.36. Both of these SNPs were imputed with very high quality across studies (R2>0.93). As indicted in
