Clinical Practice Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 7, 2018; 24(9): 1035-1045
Published online Mar 7, 2018. doi: 10.3748/wjg.v24.i9.1035
Phenotypic and genotypic characterization of inflammatory bowel disease in children under six years of age in China
You-Hong Fang, You-You Luo, Jin-Dan Yu, Jin-Gan Lou, Jie Chen
You-Hong Fang, You-You Luo, Jin-Dan Yu, Jin-Gan Lou, Jie Chen, Department of Gastroenterology, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou 310052, Zhejiang Province, China
Author contributions: Chen J, Fang YH and Luo YY designed the research; Fang YH, Luo YY, Yu JD, Lou JG and Chen J performed the research; Fang YH analyzed the data; Fang YH and Chen J wrote the paper.
Supported by Zhejiang Province Medical Platform Backbone, No. 2017KY436.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of the Children’s Hospital of Zhejiang University School of Medicine.
Conflict-of-interest statement: The authors have no financial relationships to disclose.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Jie Chen, MD, Attending Doctor, Chief Doctor, Department of Gastroenterology, Children’s Hospital, Zhejiang University School of Medicine, 3333 Bin Sheng Road, Hangzhou 310052, Zhejiang Province, China. hzcjie@zju.edu.cn
Telephone: +86-571-87061007
Received: December 12, 2017
Peer-review started: December 12, 2017
First decision: January 18, 2018
Revised: January 31, 2018
Accepted: February 8, 2018
Article in press: February 8, 2018
Published online: March 7, 2018
ARTICLE HIGHLIGHTS
Research background

Very-early-onset inflammatory bowel disease (VEO-IBD) patients show a close association with primary immunodeficiency diseases, defined as monogenic IBD. More than 50 VEO-IBD related genes have been reported to date. Nonetheless, the incidence of monogenic IBD in Chinese population remains unknown.

Research motivation

Most reports regarding monogenic IBD were based on small population or case report, with only a small number of genes investigated. This study reports the largest cohort of genetically screened patients with VEO-IBD from China.

Research objectives

The objective of this research is to characterize monogenic IBD phenotypically and genotypically via genetic testing and to analyze clinical differences between monogenic and nonmonogenic VEO-IBD patients.

Research methods

A retrospective analysis of children aged 0 to 6 years diagnosed with VEO-IBD in a tertiary hospital in southern China from 2005 to 2017 was performed. Clinical data for VEO-IBD patients were collected, and their genetic characteristics were analyzed using whole exome sequencing or target gene panel sequencing.

Research results

Nine patients (16.7%) were identified to have monogenic IBD by genetic testing. Five patients were shown to have IL10R mutation, two patients had chronic granulomatous disease, one patient had common variable immunodeficiency disease, and one patient had X-linked inhibitor of apoptosis deficiency.

Research conclusions

A high proportion of monogenic IBD was observed among the VEO-IBD group, especially with disease onset before the age of 6 mo. IL10RA was the predominant mutation in this cohort. Monogenic IBD and nonmonogenic IBD demonstrated similar clinical features. Next-generation sequencing played an important role in the diagnosis of monogenic IBD.

Research perspectives

Next-generation sequencing revealed a high proportion of monogenic IBD in our VEO-IBD cohort. Multicenter prospective studies are expected to determine the incidence of monogenic IBD in the Chinese VEO-IBD population and to investigate the genetic characteristics of monogenic IBD in China.