Letters To The Editor
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 28, 2018; 24(28): 3198-3200
Published online Jul 28, 2018. doi: 10.3748/wjg.v24.i28.3198
Genetic analysis is helpful for the diagnosis of small bowel ulceration
Junji Umeno, Takayuki Matsumoto, Atsushi Hirano, Yuta Fuyuno, Motohiro Esaki
Junji Umeno, Atsushi Hirano, Yuta Fuyuno, Motohiro Esaki, Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Fukuoka 812-8582, Japan
Takayuki Matsumoto, Division of Gastroenterology, Department of Internal Medicine, Faculty of Medicine, Iwate Medical University, Morioka, Iwate 020-8505, Japan
Motohiro Esaki, Department of Endoscopic Diagnostics and Therapeutics, Saga University Hospital, Saga 849-8501, Japan
Author contributions: Umeno J and Hirano A wrote this letter; Matsumoto T, Fuyuno Y and Esaki M revised the letter.
Supported by the Practical Research Project for Rare/Intractable Diseases from Japan Agency for Medical Research and Development (AMED), No. 15ek0109053h0002; and the Japan Society for the Promotion of Science (JSPS) KAKENHI, No. 25460953.
Conflict-of-interest statement: None declared.
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: Junji Umeno, MD, PhD, Doctor, Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan. jumeno@intmed2.med.kyushu-u.ac.jp
Telephone: +81-92-6425261 Fax: +81-92-6425273
Received: May 17, 2018
Peer-review started: May 18, 2018
First decision: June 4, 2018
Revised: June 7, 2018
Accepted: June 22, 2018
Article in press: June 22, 2018
Published online: July 28, 2018

The widespread use of capsule endoscopy and balloon-assisted endoscopy has provided easy access for detailed mucosal assessment of the small intestine. However, the diagnosis of rare small bowel diseases, such as cryptogenic multifocal ulcerous stenosing enteritis (CMUSE), remains difficult because clinical and morphological features of these diseases are obscure even for gastroenterologists. In an issue of this journal in 2017, Hwang et al reviewed and summarized clinical and radiographic features of 20 patients with an established diagnosis of CMUSE. Recently, recessive mutations in the PLA2G4A and SLCO2A1 genes have been shown to cause small intestinal diseases. The small bowel ulcers in each disease mimic those in the other and furthermore those found in nonsteroidal anti-inflammatory drug-induced enteropathy. These recent and novel findings suggest that a clinical diagnosis exclusively based on the characteristics of small bowel lesions is possibly imprecise. Genetic analyses seem to be inevitable for the diagnosis of rare small bowel disorders such as CMUSE.

Keywords: Cryptogenic multifocal ulcerous stenosing enteritis, Chronic nonspecific multiple ulcers of the small intestine, Chronic enteropathy associated with SLCO2A1 gene, Crohn’s disease

Core tip: The purpose of this letter to the editor is to comment on the differential diagnosis of small intestinal ulcers. Mutations in PLA2G4A and SLCO2A1, encoding proteins involved in the production and degradation of prostaglandins, cause rare gastrointestinal diseases with multiple small intestinal ulcers. In addition to conventional gastrointestinal examinations, genetic analyses are helpful in distinguishing these diseases.