FIGURE 4:

Mendelian randomization (MR) analysis of the effect of lymphocyte count on Parkinson’s disease (PD) risk. Scatter plot showing per-effect-allele single nucleotide polymorphism (SNP) associations with lymphocyte count and the per-allele log odds ratio [OR] for PD. Note that to orient the MR effects in the same direction as the observational estimate, we reversed the effect directions for SNP associations with lymphocyte count such that a 1 unit increase on the x axis reflects a genetically-predicted 1 standard deviation (SD) reduction in lymphocyte count for each copy of the effect allele. The model fit lines indicate MR estimates from different MR methods.