Our study confirms IRGM rs13361189 and rs4958847 polymorphisms to be important for Crohn's disease susceptibility and phenotype modulation, in accordance with previous findings.
The analysis showed modest significant association for the rs13361189, rs4958847 and rs10065172 variants in Crohn's disease (CD): the risk estimates for the allele contrast were OR=1.306 (1.200-1.420), p=5.2 × 10(-10), OR=1.182 (1.082-1.290), p=0.0002, and OR=1.248 (1.057-1.473), p=0.009 respectively (still significant when the p value was Bonferroni adjusted to 0.017).
In addition, our meta-analysis data showed that IRGM rs13361189 and rs4958847 polymorphisms were associated with CD (rs13361189 C allele P=1.07 x 10(-19), pooled OR=1.34; rs4958847 A allele P=2.78 x 10(-17), pooled OR=1.31) and UC (rs13361189 P=0.0069, pooled OR=1.16; rs4958847 P=0.014, pooled OR=1.13).
NCF4 and IRGM were significantly associated with ileal CD (P-value(rs4821544)=0.0090, odds ratio (OR)=1.425, 95% confidence interval (CI): 1.092-1.859; P-value(rs13361189)=0.0017, OR=1.942, 95% CI: 1.274-2.959; P-value(rs4958847)=0.0022, OR=1.767, 95% CI: 1.224-2.558), but not with other forms of inflammatory bowel disease (IBD).