Admixed populations such as African Americans and Hispanic Americans are often medically underserved and bear a disproportionately high burden of disease. Owing to the diversity of their genomes, these populations have both advantages and disadvantages for genetic studies of complex phenotypes. Advances in statistical methodologies that can infer genetic contributions from ancestral populations may yield new insights into the aetiology of disease and may contribute to the applicability of genomic medicine to these admixed population groups.
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The authors are grateful to N. Patterson, D. Reich, A. Williams and N. Zaitlen for helpful discussions. This work was funded by US National Institutes of Health grants RC1 GM091332 (B.P. and A.L.P.), R01 AR050267 and R01 DK071185 (M.F.S.).
The authors declare no competing financial interests.
- Admixture mapping
A technique for mapping a risk locus for a specific trait based on a statistical signal of unusual local ancestry at the risk locus.
- Ancestry-informative markers
(AIMs). Markers with large differences in allele frequency between two or more populations that can be used to infer genetic ancestry.
A continuum of genetic ancestry formed by migration or admixture between two populations.
- Genome-wide ancestry
The overall genetic ancestry of an individual as determined from SNP genotypes or other data distributed across autosomal chromosomes.
- Hidden Markov model
(HMM). A generalization of a mixture model in which data are generated as a function of unknown (hidden) states, with transitions between states governed by a Markov process.
The inference of genotypes of markers that have not been directly genotyped by making use of information from haplotype reference panels such as the HapMap or 1000 Genomes panels.
- Local ancestry
The genetic ancestry of an individual at a particular chromosomal location, defined as 0, 1 or 2 copies from each ancestral population considered.
- Multi-way admixture
We use this term to indicate admixture between more than two continental population groups, such as in Latinos who descend from admixture between Europeans, Native Americans and West Africans.
- Principal components analysis
A dimensionality reduction technique used to infer continuous axes of variation in genetic data, often representing genetic ancestry.
- Two-way admixture
In this article, this term indicates admixture between two continental population groups, such as in African Americans who descend from admixture between Europeans and West Africans.
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Seldin, M., Pasaniuc, B. & Price, A. New approaches to disease mapping in admixed populations. Nat Rev Genet 12, 523–528 (2011). https://doi.org/10.1038/nrg3002
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