Fig. 8. ARHGEF2 containing IBD risk locus on chromosome 1 (1q22).

The single nucleotide polymorphism (SNP) rs670523 was previously associated to IBD by GWAS⁴⁴. The graph shows the linkage disequilibrium structure of the proxy SNPs to rs670523 (dark gray) calculated using LDlink⁶⁴ as r² values based on the 1000 Genomes phase 3v5 CEU + GBR European reference haplotypes (left y axis). The proxy SNPs are color-coded according to their r² values and positioned at their chromosomal location (x-axis) over the genes found at this locus. The right y-axis shows the results of the MIS (Myeloid Inflammatory Score) epigenetic scoring method that we previously described⁶ and designed to prioritize candidate genes involved in inflammatory processes in myeloid cells based on functional genomics information. The MIS for each gene is shown by a blue bubble over its transcriptional start site with a diameter proportional to the MIS. ARHGEF2 is found in strong LD with rs670523 and has the highest MIS within this IBD risk locus.