Genotype distributions at all polymorphisms were consistent with HWE expectations in genotyped founders (or parents) in both AA and EA families, and in genotyped unrelated AA or EA cases or controls, except the genotype distribution of rs6713532 in EA controls [P=0.039; non-significant when corrected for multiple comparisons at α level of 0.010 (α=0.050/5)]. Substantial pair-wise LD was observed between adjacent markers (rs6719226 to rs6713532) in both AA and EA samples (Figure 1). A moderate LD was observed between rs6713532 and rs1866146 in EA samples. Ancestry proportions of four groups of unrelated subjects are shown in Figure 2. Genetically identified ethnicity was consistent with self-reported ethnicity (African ancestry proportions >50% for all AA subjects, and European ancestry proportions >50% for all EA subjects). The degree of admixture of the European ancestry (the green part) in AA subjects was only 3.3%, and the degree of admixture of the African ancestry (the red part) in EA subjects was only 1.3%. The low estimated admixture rates in AAs and EAs probably reflect in part the statistical effects of the lack of a non-admixed African sample in the cluster analysis.
