Investigation of inflammatory bowel disease risk factors in 4 families in central China

Shufang Xu; Hui Zou; Heng Zhang; Siying Zhu; Rui Zhou; Jin Li

doi:10.3892/etm.2017.5582

Investigation of inflammatory bowel disease risk factors in 4 families in central China

Exp Ther Med. 2018 Feb;15(2):1367-1375. doi: 10.3892/etm.2017.5582. Epub 2017 Nov 28.

Authors

Shufang Xu¹, Hui Zou¹, Heng Zhang¹, Siying Zhu², Rui Zhou², Jin Li²

Affiliations

¹ Key Laboratory for Molecular Diagnosis of Hubei, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China.
² Hubei Clinical Center and Key Laboratory for Intestinal and Colorectal Diseases, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China.

Abstract

The prevalence of inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is increasing markedly in China. The present study performed pedigree analysis of 4 families with a history of IBD and investigated the association of genetic and environmental factors with susceptibility to IBD. A total of 10 IBD patients (8 CD patients and 2 UC patients) and 90 family members were included in the present study. The clinical characteristics of familial subjects were compared with those of patients with sporadic IBD. Previously reported mutations, namely interleukin-10 receptor (IL10R)-A Thr84Ile, IL10RA Gly141Arg, IL10RB Trp159X, X-linked inhibitor of apoptosis (XIAP) Cys203Tyr, nucleotide-binding oligomerization domain-containing protein 2 (NOD2) Arg702Trp, NOD2 Gly908Arg and NOD2 Leu1007fsinsC, were screened in the patients with IBD, and selected demographic factors were compared between the patients and their unaffected family members. It was observed that single-gene and multi-gene inheritance patterns contributed to IBD in Chinese families. Based on data from the registry system, the ratio of patients with a family history of IBD was 1.25%, which was lower than that in the Western population. First-degree relatives were found to be more susceptible to IBD, and siblings were affected more frequently. Furthermore, the median age of diagnosis was younger in familial patients than in sporadic patients (29.0 vs. 36.0 for CD; 35.5 vs. 41.0 for UC). However, none of the 7 susceptibility loci were present in any of the familial patients. Immigration was a significant risk factor of IBD (odds ratio: 4.667; 95% confidence interval: 1.165-18.690; P=0.021). In conclusion, genetic heterogeneity exits between Chinese families with IBD and the Western population. The present findings suggest that genetic background and environmental factors serve a role in the pathogenesis of IBD.

Keywords: Crohn's disease; genetic heterogeneity; genetic susceptibility; inflammatory bowel disease; pedigree analysis; ulcerative colitis.