Objective: To investigate the causal role with Inflammatory bowel disease(lBD) and epilepsy through Mendelian randomization (MR) approach.

Methods: Genetic association data for IBD were collected through the International IBD Genetics Consortium (25 042 cases and 34 915 controls) and genetic association data for epilepsy were from International League Against Epilepsy Consortium (15212 cases and 29677 controls) MR analyses were performed using the summary level data for  epilepsy extracted above genetic association data to obtain the causal estimates. The inverse variance weighting (IVW) method  of the random effects model was the main analysis method supplemented by the WME and MR-Egger methods, the OR value was used to present the results.

Results: A total of 70 single nucleotide polymorphism(SNP) closely associated with epilepsy as instrumental variables from the pooled database were obtained,and the IVW results OR=0.98,95% C: 0.96~0.99,P=0.01) indicated that genes predicted IBD has a causal relationship with epilepsy. MR-Egger regression results(P=0.77) and PRESS0 test indicated that there was no horizontal pleiotropy of genes in our findings.

Conclusion: There is a causal association between epilepsy and lBD, and the variant of rs212402 may be the key to lBD affecting epilepsy.