FAMILIAL AGGREGATION OF INFLAMMATORY BOWEL-DISEASE - A POPULATION-BASED STUDY IN SOUTH LIMBURG, THE NETHERLANDS

Background: The aim of our study was to investigate the prevalence of Crohn's disease (CD) and ulcerative colitis (UC) in first-degree relat ives of IBD patients living in a well-defined area. Methods: IBD patie nts known at the IBD Registration South Limburg as well as population controls were asked about the occurrence of IBD in their first-degree relatives. Results: IBD was reported and confirmed in 16 (out of 1554) relatives by 11 (out of 245) patients. Prevalence of IBD was highest for siblings (1.5%) and children (1.3%), while only 0.2% of the parent s were affected with IBD. among relatives of the control subjects, IBD was observed in 0.8% (versus 4.5% in IBD patients), resulting in an o dds ratio of 5.7 (95% CI: 2.0-16.7). Conclusions: The observed risk of IBD for first-degree relatives of IBD patients was higher than in con trols. However, the risk in our population is lower than has been repo rted by other centres, possibly because of the population-based charac ter of our study.