The observed rates of trans-ethnic replication between Europeans and East Asians indicate that a considerable fraction of risk loci associated with the 28 diseases is shared between the two Continental groups. As to the sharing and frequency of risk variants, it can be explored even if the causal variants themselves remain undiscovered. First, the possibility that the same causal variants underlie association in the two continents is reinforced by the strong correlation between the ORs for SNPs discovered in European GWAS and their replication OR in the largest East Asian study (Spearman's ρ = 0.82, P<10−16, Figure 1; we used the log(OR) to ensure symmetry around 1). Also, the slope of the linear regression of the two log(OR) is very close to 1 (1.03, SE = 0.064, P<10−16), which indicates that the log(OR) found in Europeans is the best predictor of the East Asian log(OR). These figures would be unexpected if GWAS hits were synthetically generated by population-specific rare causal variants, as their effect size and Linkage Disequilibrium (LD) with the replicated SNP would be different in each population. Moreover,
