Genetic risk variants in intestinal inflammatory disorders

Abstract

This thesis includes work on the genetics of intestinal inflammatory disorders, concentrating on coeliac disease and Crohn’s disease. It explores how common genetic variants influence risk of complex phenotypes including immunological intolerance to gluten (coeliac disease) and intolerance to therapeutic agents (azathioprine and mercaptopurine) used in the treatment of intestinal inflammatory diseases. Finally it presents work aiming to move from genetic associations with complex phenotypes to understanding of how these variants modulate immunological processes. Results of a large genome wide association study that identified more than 13 new genetic risk regions influencing susceptibility to coeliac disease are presented. Results of a genome wide association study of azathioprine and 6-mercaptopurine-induced pancreatitis in inflammatory bowel disease-affected individuals are presented. Finally, a cell cytokine release assay for the prostaglandin EP4 receptor was developed, with a view to investigating how SNPs associated with Crohn’s disease in the 5p13.1 region influence EP4 receptor signalling and contribute to disease pathogenesis. This work highlights some of the challenges in moving from SNP-disease associations identified in GWASs to understanding how genetic variants change biological processes.