We again used the LCT/MCM6 region as a positive control. Fig 1D shows the regional plots of iHS values in the LCT/MCM6 region for EUR, ASN and AFR populations. As expected, the AFR population shows few extreme values (only 3.2%) and this does not differ significantly from the negative control. In EUR and ASN, the overall average proportion of extreme values for this region is 80.4% and 9.1%, respectively (Table 1). The clustering of extreme iHS values in the genic areas of this region is consistent with what is known about large-scale positive selection at this locus in the EUR population and to a lesser extent in the ASN population [27]. This demonstrates the validity of this approach for identifying genes undergoing selection.
