Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 7, 2020; 26(17): 2049-2063
Published online May 7, 2020. doi: 10.3748/wjg.v26.i17.2049
Ethnic differences in genetic polymorphism associated with irritable bowel syndrome
Qi-Yun Xiao, Xiu-Cai Fang, Xiao-Qing Li, Gui-Jun Fei
Qi-Yun Xiao, Xiu-Cai Fang, Xiao-Qing Li, Gui-Jun Fei, Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
Author contributions: Fang XC designed the review; Xiao QY performed the literature search and drafted the manuscript; Fang XC, Li XQ, and Fei GJ revised the manuscript; all authors read and approved submission of the final version.
Supported by the Program of International S & T Cooperation, No. 2014DFA31850; and National Natural Science Foundation of China, No. 81870379.
Conflict-of-interest statement: There are not any financial or other interests regarding the submitted manuscript that might be construed as a conflict of interest.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Xiu-Cai Fang, MD, Chief Physician, Full Professor, Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1, Shuaifuyuan, Dongcheng District, Beijing 100730, China.
Received: January 31, 2020
Peer-review started: January 31, 2020
First decision: February 24, 2020
Revised: March 25, 2020
Accepted: April 4, 2020
Article in press: April 4, 2020
Published online: May 7, 2020

Genetic polymorphism is associated with irritable bowel syndrome (IBS) in terms of susceptibility and clinical manifestations. Previous studies have shown that genetic polymorphism might play a key role in the onset and progression of IBS by modulating components of its pathogenesis such as the gut-brain axis, gastrointestinal motility, inflammatory activity, and immune status. Although underlying pathophysiological mechanisms have not been fully clarified, the potential ethnic differences that are present in worldwide genetic studies of IBS deserve attention. This review surveyed numerous studies focusing on IBS-associated single nucleotide polymorphisms, and investigated the ethnic disparities revealed by them. The results demonstrate the need for more attention on ethnic factors in IBS-related genetic studies. Taking ethnic backgrounds into accounts and placing emphasis on disparities potentially ascribed to ethnicity could help lay a solid and generalized foundation for transcultural, multi-ethnic, or secondary analyses in IBS, for example, a meta-analysis. Broader genetic studies considering ethnic factors are greatly needed to obtain a better understanding of the pathophysiological mechanisms of IBS and to improve the prevention, intervention, and treatment of this disease.

Keywords: Irritable bowel syndrome, Ethnicity, Genetic polymorphism, Single nucleotide polymorphism, Genome-wide association, Pathogenesis

Core tip: The present review focused on the phenomenon of ethnic discrepancies in irritable bowel syndrome-related genetic studies by gathering up-to-date original research and meta-analyses. We discuss the ethnic background and its potential impacts on the inconsistent results of studies, emphasizing the consideration of ethnicity in designing and analyzing irritable bowel syndrome-related genetic investigations, especially for multi-ethnic, transnational, and cross-cultural studies.