Estimated PD risk profile for the five cohorts genotyped using the Immunochip.

Risk scores for the 16 confirmed loci were computed using the odds ratio estimated from the genome-wide case-control genotype data. Individuals were split into quintile on the basis of their risk scores. The odds ratios quantify the effect of the computed risk quintile on the probability of being a PD case (one-degree-of-freedom logistic trend test with the PD status as a binary outcome variable and the quintiles, coded as 1–5, as covariates). The first quantile group was taken as a reference group. OR: odds ratio, CI: confidence interval.