Table 3.

Group Admixture Estimates by CHS Clinic Site or by Clusters Inferred on the Basis of Genetic Similarity^[Note]

		Estimated Ancestral Proportions(% ± SE)
BiodemographicCharacteristic	N	African	European	Native American
Clinical centera:
Winston-Salem	299	79.1 ± .9	17.0 ± 1.7	3.9 ± 2.1
Sacramento	214	74.4 ± 1.0	20.6 ± 2.0	4.9 ± 2.4
Pittsburgh	285	75.2 ± .9	23.9 ± 1.8	.9 ± 2.2
Genetic similarity:
Cluster 1	467	86.4 ± .7	12.1 ± 1.3	1.6 ± 1.7
Cluster 2	32	76.1 ± 2.3	25.0 ± 5.0	.0 ± 6.0
Cluster 3	74	41.4 ± 1.6	37.1 ± 3.6	21.5 ± 4.2
Cluster 4	236	67.2 ± 1.0	33.2 ± 2.1	.0 ± 2.6

Note.— Group ancestral proportions and SEs were estimated separately for each subpopulation by use of the program ADMIX 2.0 (Dupanloup and Bertorelle 2001), as described in the “Methods” section.

^aThe small number of subjects in the Maryland sample (n=11) were excluded from this analysis.