Fig. 1. MS GWAS study design.
Top panel: four cohorts used in the meta-analysis. Middle panel: meta-analysis and the three methods used. METAL provides a computationally efficient tool for meta-analysis of genome-wide association scans in European ancestry, MR-MEGA (middle) can identify risk variants with heterogeneous effects due to population stratification introduced by ancestry differences, whereas random-effect (bottom) is better suited for risk variants with homogeneous effect direction across different ancestries. The red dashed lines indicate p-value threshold of P < 5 × 10−8. Bottom panel: downstream analyses and their examples.