Figure 4. Excess of rare regulatory variants coincident with expression outliers.

We calculated the excess of expression outliers as a function of frequency for all SNPs within 100 kb of the transcription start site of array-quantified genes for both Europeans and Africans. We further sub-selected to only include SNPs in 17-way most conserved elements from UCSC. We observed an enrichment of conserved singleton SNPs coincident with expression outliers (Z>2; p<0.05). The confidence intervals were estimated by randomizing expression labels 200 times.