Observational Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Nov 28, 2021; 27(44): 7705-7715
Published online Nov 28, 2021. doi: 10.3748/wjg.v27.i44.7705
Autosomal recessive 333 base pair interleukin 10 receptor alpha subunit deletion in very early-onset inflammatory bowel disease
Jia-Jia Lv, Wen Su, Xiao-Yan Chen, Yi Yu, Xu Xu, Chun-Di Xu, Xing Deng, Jie-Bin Huang, Xin-Qiong Wang, Yuan Xiao
Jia-Jia Lv, Wen Su, Yi Yu, Xu Xu, Chun-Di Xu, Xing Deng, Jie-Bin Huang, Xin-Qiong Wang, Yuan Xiao, Department of Pediatrics, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, Shanghai Province, China
Xiao-Yan Chen, Department of Pathology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, Shanghai Province, China
Author contributions: Lv JJ and Su W contributed equally to this work; Lv JJ and Su W performed the experiments, data acquisition, analysis and interpretation, and drafting of the article; Chen XY, Yu Y, Xu X, Xu CD, Deng X, and Huang JB analyzed the data and critically revised the article; Wang XQ and Xiao Y designed the project and critically revised the article for important intellectual content; and all authors have read and approved the final manuscript.
Supported by the National Natural Science Foundation of China, No. 81741103.
Institutional review board statement: The study was reviewed and approved by the Ethics Committee of Ruijin Hospital (Shanghai).
Informed consent statement: All study participants or their legal guardians provided informed consent prior to study enrollment.
Conflict-of-interest statement: There are no conflicts of interest to declare.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement checklist of items.
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: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Yuan Xiao, MD, PhD, Associate Chief Physician, Deputy Director, Lecturer, Department of Pediatrics, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Ruijin 2nd Road, Shanghai 200025, Shanghai Province, China. xy11438@rjh.com.cn
Received: May 31, 2021
Peer-review started: May 31, 2021
First decision: July 1, 2021
Revised: July 9, 2021
Accepted: November 9, 2021
Article in press: November 9, 2021
Published online: November 28, 2021
Research background

Interleukin 10 receptor alpha (IL10RA) gene mutations constitute the most common monogenic disease in East Asia, affecting the health of children. However, identifying disease-causing mutant sites or copy number variants remains challenging in the clinic.

Research motivation

According to the results of our previous study, severe clinical symptoms as well as significantly increased serum IL-10 indicate IL10RA dysfunction, a monogenic phenotype of very early-onset inflammatory bowel disease (VEO-IBD). In addition, such very early-onset IBD showed a heterozygous IL10RA gene mutation by whole exon sequencing, leading to the employment of WGS and subsequent identification of 333-bp deletions in IL10RA.

Research objectives

We investigated the potential disease-causing gene mutations missed by WES and target gene panel sequencing (TGPS). Our results may contribute to monogenic disease diagnosis.

Research methods

Four patients clinically diagnosed with VEO-IBD during the past 5 years were recruited for this study. Based on their severe clinical phenotypes and the fact that before hospitalization, three patients harbored an IL10RA mutation (c.301C>T, p.R101W in one patient; c.537G>A, p.T179T in two patients), as detected by TGPS and trio-WES, and because WES did not show conclusive results in the fourth patient, we performed whole-genome sequencing (WGS) on patients A and B and reanalyzed the trio-WES data from patients C and D. To verify the functional change caused by the novel mutation, peripheral blood mononuclear cells (PBMCs) from patient D were isolated and stimulated in vitro with lipopolysaccharide (LPS), IL-10, and LPS + IL-10. Serum IL-10 levels in four patients and tumor necrosis factor-α (TNF-α) in the cell supernatant were determined by ELISA. Phosphorylation of signal transducer and activator of transcription 3 (STAT3) at Tyr705 and Ser727 in PBMCs was determined by western blot analysis.

Research results

Results of WGS revealed a novel 333-bp deletion encompassing exon 1 of IL10RA in patients A and B, which was also found in patients C and D after reanalyzing their WES data. Patient D was homozygous for the 333-bp deletion. All four patients showed elevated serum IL-10 levels. In vitro, IL-10-stimulated PBMCs from patient D failed to induce STAT3 phosphorylation at Tyr705 and minimally suppressed TNF-α production induced by LPS. Phosphorylation at Ser727 in PBMCs was not affected by LPS or LPS + IL-10 in both healthy subjects and patient D.

Research conclusions

Genome-wide uniformity of coverage of WGS identified a novel 333-bp deletion in IL10RA in four patients with VEO-IBD, whereas the results of initially performed WES were inconclusive. WGS, which was more informative than WES, is the most important comprehensive second-tier genomic test for monogenic diseases in the clinic.

Research perspectives

We will customize a multiplex ligation-dependent amplification probe of the 333-bp deletion in IL10RA to help diagnose IL10RA mutation-related monogenic diseases.