New links to the pathogenesis of Crohn disease provided by genome-wide association scans

Abstract

Studies of Crohn disease have benefited spectacularly from genome-wide association scans. Newly identified susceptibility loci support previously suspected underlying pathways, but also reveal hitherto unexpected putative mechanisms of this disease. Genome-wide association scans (GWAS) using large case–control samples and several hundred thousand genetic markers have uncovered at least ten new genomic regions associated with susceptibility to Crohn disease, a chronic inflammatory bowel disorder. The new loci include genes with diverse roles in the immune response and several gene deserts, which may contain regulatory sequences or encode novel functional transcripts. The results so far suggest that genome scans may re-define our ideas on the nature of causal variants in complex disease.