Figure 4

Haplotype bifurcation plots and extended haplotype homozygosity diagrams for the CYP2C19 * 3 slow metabolizing allele in Asians and the gain-of-function allele CYP2C19 * 17 in Europeans. The plot is centred on the common, slow metabolizing allele which is common in Asians CYP2C19*3 at SNP positions rs12778026, rs4986893 (CYP2C19*3) and rs4304692 and EHH was measured away from the core in Asians. The high activity allele core region in Europeans is focused on SNP positions rs11568732, rs12248560 (CYP2C19*17) and rs4986894 and the haplotype extension measured from the core locus. A. CYP2C19*3 haplotype structure in Japanese and Han Chinese. The CYP2C19*3 mutation is carried on haplotype TAA (haplotype 4) which shows some evidence of extended homozygosity. B. CYP2C19*17 haplotype structure in Europeans. The CYP2C19*17 variant is carried on haplotype TTT (haplotype 4) that extends along the genome without a breakdown of its homozygosity showing evidence of selection in Europeans. The haplotype table below the figure describes the CYP2C19*17-containing haplotypes in the European population.