The final GWAS meta-analysis consisted of 8,265,319 SNPs in 4,819 Tourette syndrome cases and 9,488 controls. No evidence for residual population stratification or systematic technical artifact was observed in any of the individual datasets (Figure S2) or in the final meta-analysis (λ=1.072, λ1000=1.011, Figure 1). LDSC indicated that 86% of the observed test statistic inflation was attributable to an underlying genome-wide polygenic signal (Figure S3). PRS analyses in each individual GWAS dataset derived using a “leave one out” approach, and in the deCODE sample, indicated genetic homogeneity across all contributing datasets (Figures S4 and S5).
