In the primary meta-analysis of European-derived samples, no SNP surpassed a genome-wide significant threshold of p<5.0×10−8 (Figure 1). The top 5 LD-independent loci are annotated in Table 2; full annotation of all SNPs with p<1×10−3 are provided in Table S2. The SNP with the strongest signal, rs7868992, lies on chromosome 9q32 within an intron of COL27A1 (p=1.85 ×10−6; Figure S9). The other four top independent GWAS signals include rs6539267, an intronic SNP within POLR3B on chromosome 12q23 (p=7.41 ×10−6; Figure S10); rs13063502, a SNP that lies in a 1.7 Mb intergenic region on chromosome 3q13 (p=8.96 ×10−6; Figure S11); rs7336083, located on chromosome 13q31 within a 1.9 Mb intergenic region between SLITRK6 and SLITRK112 (p=9.49 ×10−6; Figure S12); and rs769111, an intergenic SNP on chromosome 7p21 between THSD7A and TMEM106B (p=1.20 ×10−5;Figure S13). No effect-size heterogeneity was present between the three European-derived subpopulations for SNPs rs7868992, rs6539267 and rs7336083 (Figures S9-13). rs13063592 and rs769111 demonstrated moderate heterogeneity (I2=45.4% and 64.2%, respectively), though the direction of effect was consistent across the EU, AJ and FC populations.
