Fig. 1. Position of genotyped SNPs within the ST8SIA2 gene, and phased haplotypes.

The haplotype block structure across the entire ST8SIA2 gene (chr15:92,910–92,995 Mb; hg18) is shown, determined from 174 European (CEU, GBR) individuals from phase 1 of the 1000 Genomes project (MAF > 0.2). ST8SIA2 gene structure is shown above, with black bars indicating exon positions and the promoter region lying in the 5’ direction. Relative LD strength is indicated by strength of red coloring, whereby dark red indicates high LD (D’ > 0.8). Blue arrows indicate position of SNPs genotyped in the current study (rs4586379, rs2035645, rs4777974, and rs3784735). The main haplotypes (frequency > 0.05) defined across the four genotyped SNPs are shown in the inset, alongside their observed frequencies (freq). The TTGA and CGAC haplotypes (indicated in the red and green boxes, respectively) correspond to the previously identified “risk” and “protective” haplotypes, as reported in McAuley et al.¹²