Admixture mapping and the role of population structure for localizing disease genes

Admixture mapping, or mapping by admixture linkage disequilibrium, is a disease mapping strategy that has gained considerable popularity in recent years. It exploits the long-range linkage disequilibrium generated by admixture between genetically distinct ancestral populations. Compared to case-control association designs, admixture mapping requires fewer markers, and is more robust to allelic heterogeneity. At the same time, admixture mapping can be more powerful, and can achieve higher mapping resolution than traditional linkage studies, provided that the underlying trait variants occur at sufficiently different frequencies in the ancestral populations. In this chapter, we describe the recent methodology and software development, review successful applications, and comment on the future of this approach.