Schematic structure of the IRGM gene.

A) Gene segments with lengths and all SNPs that are recognized so far are given. SNPs associated with Crohn's Disease, SNPs genotyped in the present study and the SNP associated with protection from TB caused by the EUAM-lineage of M. tuberculosis are indicated. The nucleotide positions of SNPs indicated by rs/ss numbers are listed in Table 1. B) Estimates of pairwise linkage disequilibria (LD) between IRGM variants with the LD measure of r² assuming Hardy-Weinberg equilibrium. C) Potential loss of transcription factor binding sites (ARNT, PAX5, AHR) in sequences carrying the IRGM −261T allele. D) Potential accumulation of transcription factor binding sites (FOXP3, GR, PR A/PR B), depending on the number of tetranucleotide repeats (rs60800371; [15]).