The investigators initiated this research study in 1996 with the overall goal of identifying IBD susceptibility genes. In the beginning, the major focus was recruitment of multiply affected IBD pedigrees for linkage studies, but the investigators have since expanded the study to include singleton cases and spousal/friend as well as population controls for comparison purposes The investigator's recruitment goal is 2500 subjects.
Blood samples obtained from participants are used to isolate lymphocytes for storage, serum for serological analysis of antibodies and other proteins relevant to IBD and DNA for genotyping or sequencing. Lymphocytes may be transformed with EBV to establish immortalized lymphoblastoid cell lines. These cell lines can be used as a secondary DNA source or to study IBD relevant gene, protein expression and cell function