Current Status and Future Prospects of Inflammatory Bowel Disease Genetics.

Background: The genetic background of inflammatory bowel diseases (IBDs) has been explored using genetic analysis techniques, such as genome-wide association studies for the population and whole-exome sequencing analyses of family lineages in cases of very early onset.

Summary: The results of genetic analysis for IBD indicated the involvement of innate and adaptive immune system variations and epithelial abnormalities in the pathogenesis of IBD. Several associated genes were also reported, indicating that IBD occurs in a heterogeneous population with an extremely diverse background. The genetic background of IBDs is currently being studied to understand not only its onset but also its prognosis, response to treatment, and adverse effects. In the future, it will be possible to use an individual's genetic information for determining appropriate treatment. In Japan, the NUDT15 polymorphism test is performed before administering thiopurine preparations. However, because of racial differences in genetic analysis, biased analysis toward some racial groups may result in overlooking important genetic backgrounds of IBD.

Key message: Studies of IBDs in a more diverse range of races are expected to elucidate genetic factors through a transethnic analysis, thereby aiding the development of novel treatments and precision medicine for IBDs.