As a reference population, we used a subset (60 Yoruba females; YRI) of the 270 samples from the International HapMap Project [52] run on the Affymetrix Human SNP 6.0 array [48]. Copy numbers were normalized to 2 for ease of comparison. Chromosomal locations of regions of significant copy number alteration are shown: 468GFP vs the Yoruba reference population, 468LN vs Yoruba, and 468LN vs 468GFP.