variants while accounting for LD between these variants64. Because GSMR accounts for LD, genetic variants that were included in GSMR instruments were pruned at a higher threshold of R2<0.05 (instead of R2<0.001 for the other MR analyses). Zhu et al. (2018, 64) showed that the gain of power from including SNPs in higher LD than 0.05 is limited. GSMR also allows extra filtering for SNPs that are suspected to have pleiotropic effects on both the exposure and the outcome (HEIDI filtering).
