None of the SNPs exceeded the genome-wide threshold for significance, although several of the top hits were also identified among top hits in either the trio analysis or in the case-control analysis (Figure S12). Using the sign test with 3616 LD-pruned SNPs with p<0.01, there was evidence for increased consistent directionality (1907/3616=0.52; p=5.25 × 10-4 for 1-sided binomial test) between the trios and the combined case-controls. The top 38 OCD-associated SNPs in this meta-analysis, with p-values<5×10-5, are presented in Table 1. For example, the top signal (p=4.99×10-7), rs297941 near FAIM2, (LFG), was also the fifth ranked SNP in the case-control analysis. FAIM2 is highly expressed in the central nervous system and plays a role in Fas-mediated cell death.61 When rs6131295 (the SNP with significant genome-wide association in the trio sample) was meta-analyzed along with the case-control sample, the combined p-value significance decreased to 3.62×10-5.
