Admixture mapping as a gene discovery approach for complex human traits and diseases.

Admixture mapping (AM) is a special form of conventional meiotic or recombination mapping for disease gene discovery in humans that exploits naturally occurring genetic and phenotypic differences existing in populations between which recent gene flow has occurred. Essentially, mates from two different "parental" populations with different allelic and disease-predisposing mutation profiles will produce "admixed" offspring whose genomes will be mixtures of the genomes associated with the parental populations. Strong linkage disequilibrium (LD) will exist for several generations between neighboring loci of admixed individuals and can be exploited for identifying the genomic location of trait-influencing loci. Although it may be a very clever strategy for identifying genes that influence human traits and diseases, AM can be problematic. We review the foundations, basic strategies, resources, and settings necessary for AM. We conclude that AM has potential in the identification of disease-predisposing loci, but this potential may only exist in a limited number of realistic settings.