Description

This current protocol was established as part of an NIDDK initiative to further explore genetic factors associated with IBD. Specifically, the investigators are interested in identifying the genetic, environment and socio-economical components that contribute to the development of IBD in the African American population.

IBD is believed to be caused by a combination of environmental and genetic factors. Genetic data will be examined alongside potential environmental factors such as smoking, medications, environmental exposures, and some dietary factors. Since IBD is known to predominantly affect Western, industrialized areas of the world, the investigators will also inquire about participants' socioeconomic background in hopes of identifying any previously unknown factors in the AA population that may increase the risk of IBD. These potential environmental factors will be important in association analyses using covariates as these factors can obscure potential associations or interact with genetic factors and thus contribute to genetic associations. The investigators will also obtain information as to ancestry of parents and grandparents as to best match cases with unrelated controls of similar ancestry (e.g., Caribbean, recent European or recent African ancestry could cause genetic mismatch of a case and control). At the same time, the investigators will also collect similar information (smoking, medications, environmental exposures and dietary factors) from non-African Americans for the purpose of making direct comparisons for these parameters between the different racial groups to assess the contribution of non-genetic factors for susceptibility to the development of IBD.

This study calls for recruiting AA patients and ethnically matched controls (friend or spouse). These persons will provide us with a blood sample and with information requested on a questionnaire asking the following: clinical course and history of their IBD or their general health, smoking history, socioeconomic variables and specific dietary factors known in some populations to be related to IBD etiology. Access to medical records will be used to confirm diagnoses. The clinical characteristics of IBD obtained from medical records will be summarized in a phenotyping form using a standardized NIDDK IBDGC Phenotyping Operations Manual. Controls will be asked health history to identify potentially unrecognized IBD. DNA and other biospecimens will be purified from blood. Samples and data will also be shared with the NIDDK IBDGC for use in IBDGC research projects and will be processed and maintained at NIDDK repositories.