genome - wide association studies ( gwas ) and candidate gene studies in ulcerative colitis ( uc ) have identified 18 susceptibility loci . 
 we conducted a meta - analysis of 6 uc gwas , comprising 6,687 cases and 19,718 controls , and followed - up the top association signals in 9,628 cases and 12,917 controls . 
 we identified 29 additional risk loci ( p<510 - 8 ) , increasing the number of uc associated loci to 47 . 
 after annotating associated regions using grail , eqtl data and correlations with non - synonymous snps , we identified many candidate genes providing potentially important insights into disease pathogenesis , including il1r2 , il8ra / b , il7r , il12b , dap , prdm1 , jak2 , irf5 , gna12 and lsp1 . the total number of confirmed inflammatory bowel disease ( ibd ) risk loci is now 99 , including a minimum of 28 shared association signals between crohn s disease ( cd ) and uc .