Poor generalizability of genetic studies across populations arises from the overwhelming abundance of European descent studies and dearth of well-powered studies in globally diverse populations25–28. According to the GWAS catalog, ~79% of all GWAS participants are of European descent despite making up only 16% of the global population (Figure 1). This is especially problematic as previous studies have shown that Hispanic/Latino and African American studies contribute an outsized number of associations relative to studies of similar sizes in Europeans27. More concerningly, the fraction of non-European individuals in GWAS has stagnated or declined since late 2014 (Figure 1), suggesting that we are not on a trajectory to correct this imbalance. These numbers provide a composite metric of study availability, accessibility, and use—cohorts that have been included in numerous GWAS are represented multiple times, which may disproportionately include cohorts of European descent. However, whereas the average sample sizes of GWAS in Europeans continue to grow, they have stagnated and remain several-fold smaller in other populations (Supplementary Figure 1).
