Background & Aims The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and
Crohn's disease (CD) cause significant morbidity and are increasing in prevalence among
all populations, including African Americans. More than 200 susceptibility loci have been
identified in populations of predominantly European ancestry, but few loci have been
associated with IBD in other ethnicities. Methods We performed 2 high-density, genome-
wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with …

Dear Editors: We read with great interest the original article by Brant et al. 1 The discovery of
African American (AA)-specific loci and loci that are shared between ethnic groups highlight
the importance of studying inflammatory bowel disease in other populations apart from
Europeans for a unique insight into the pathogenesis of inflammatory bowel disease. The
challenges with studying populations of non-European ancestry remains one of terminology.
The main drawback is that the difference between race and ethnicity is not clearly defined in …