GENETICS AND EPIDEMIOLOGY MAY CONTRIBUTE TO UNDERSTANDING THE PATHOGENESIS OF IBD - A NEW APPROACH IS NOW INDICATED

The present article summarizes the genetic and epidemiological factors contributing to the pathogenesis of inflammatory bowel disease (IBD) in which a consensus seems to have been reached. The factors identifie d so far strongly support the involvement of the immune system in dise ase predisposition to IBD. The models that have resulted from segregat ion analysis of families with multiple cases of IBD have led to propos e a multifactorial inheritance for Crohn's disease and ulcerative coli tis - a recessive gene in Crohn's disease and a dominant gene for ulce rative colitis. At present, the lack of genetic markers does not allow the acceptance of any one of these models. Some environmental factors , such as perinatal infections, absence of breastfeeding, smoking in C rohn's disease, influence of transfusion in diminishing relapses in Cr ohn's disease and drugs that are active in controlling these diseases, may imply the existence of an abnormal immunoregulation in the contro l of inflammation. New technology is available to approach the problem .