Genetics of inflammatory bowel disease - A personal view on progress and prospects

Clinical, epidemiological and molecular data reported in the last 5 years h ave provided strong evidence that genetic factors are important in suscepti bility to both Crohn's disease and ulcerative colitis. The model of disease inheritance which best fits the epidemiological data is that Crohn's disea se and ulcerative colitis are related polygenic diseases. However, genetic heterogeneity is likely to be extensive, and may well underlie the variabil ity in clinical presentation associated with inflammatory bowel disease. Co nsiderable progress has already been made in identifying potential disease susceptibility loci using the technique of genome-wide scanning. There is o ptimism that international collaborative studies will allow fine mapping of the loci implicated on chromosomes 16 and 12. The identification of novel susceptibility genes has become a realistic goal for investigators. Once th is has been achieved, there are likely to be immediate clinical benefits, b oth in understanding disease gathophysiology, and in disease management.