Purpose of review: This review addresses recent advances in the mapping and characterization of susceptibility genes for inflammatory bowel disease. The article discusses current information on the relation between CARD15 variants and Crohn disease and the discoveries of SLC22A4/SLC22A5 and DLG5 gene variants that also confer risk for inflammatory bowel disease.
Recent findings: Much of the recent emphasis in inflammatory bowel disease genetics research has been directed at evaluation of candidate disease susceptibility genes within inflammatory bowel disease linkage intervals. Such studies have elucidated associations of numerous gene variants with inflammatory bowel disease, but most of these require further replication and functional validation. Dissection of the molecular events coupling CARD15 mutation to Crohn's disease has also been intensively investigated and, while not resolved as of yet, has significantly advanced understanding of the intestinal immune response to microbial challenge.
Summary: The application of genetic information to diagnosis and risk prediction in inflammatory bowel disease will require comprehensive knowledge of the relevant susceptibility alleles. However, the genetic data accrued in recent years have already provided major insight into the pathophysiology of inflammatory bowel disease and identified a number of potential molecular targets for therapeutic intervention.