1.
Overview of admixture mapping
Admixture
mapping is a method for localizing disease causing genetic variants that differ
in frequency across populations. It is most advantageous to apply this approach
to populations that have descended from a recent mix of two ancestral groups
that have been geographically isolated for many tens of thousands of years: for
example, African Americans have both West African and European American ancestry.
The approach assumes that near a disease causing gene there will be enhanced
ancestry from the population that has greater risk of getting the disease. Thus
if one can calculate the ancestry along the genome for an admixed sample set,
one could use that to identify disease causing gene variants. The figure below
shows a schematic of how a disease locus would appear in an admixture scan of
patients and controls.
Fig.
1: Schematic of how a disease locus will
appear in an admixture scan.