An important consideration is that the overwhelming majority of GWAS and other genetic studies have been limited to European ancestry populations, whereas genetic variation is greatest in populations of recent African ancestry2, and studies in non-Europeans have yielded intriguing new variants33,34. Studies of populations of recent African ancestry in particular is likely to increase the yield of rare variants and narrow the large chromosomal regions of association identified in the ‘younger’ population due to extended linkage disequilibrium, or the tendency for adjacent genetic loci to be inherited together31. Isolated populations may also be of value given their potential to be enriched in unique variants35.
