Systematic Reviews
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Meta-Anal. Feb 26, 2018; 6(1): 1-8
Published online Feb 26, 2018. doi: 10.13105/wjma.v6.i1.1
Genetic studies in irritable bowel syndrome-status quo
Stefan-Lucian Popa, Dan L Dumitrascu, Romana Vulturar, Beate Niesler
Stefan-Lucian Popa, Dan L Dumitrascu, Department of 2nd Medical, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca 400006, Romania
Romana Vulturar, Department of Cell and Molecular Biology, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca 400006, Romania
Beate Niesler, Department of Human Molecular Genetics, Heidelberg University, Heidelberg 69120, Germany
Author contributions: Popa S supervised the study and has made substantial contributions to conception and correction of the drafts; Dumitrascu DL analyzed the data and drafted the paper; Vulturar R has made substantial contributions to conception and revised the drafts; Niesler B made substantial contributions to the analysis of the data, interpretation, and revised the drafts.
Conflict-of-interest statement: No potential conflicts of interest relevant to this article were reported.
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: Dr. Dan L Dumitrascu, PhD, Full Professor, Department of 2nd Medical, “Iuliu Hatieganu” University of Medicine and Pharmacy, Clinicilor Street nr3-5, Cluj-Napoca 400006, Romania. ddumitrascu@umfcluj.ro
Telephone: +40-26-4593355
Received: December 3, 2017
Peer-review started: December 4, 2017
First decision: December 27, 2017
Revised: January 17, 2018
Accepted: February 24, 2018
Article in press: February 25, 2018
Published online: February 26, 2018
Abstract
AIM

To evaluate the most common studied genetic polymorphisms that may have an etiological role in irritable bowel syndrome (IBS).

METHODS

The data base PubMed was searched for studies analyzing the association between gene polymorphisms and IBS. All original full papers, written in English, were retained for further analysis. The retrieved papers were further systematized according to those polymorphisms that have been detected in IBS.

RESULTS

Considering these criteria, our literature search found 12 polymorphisms, residing in 10 genes, which were reported to be consistently associated with IBS. The initial search identified 189 articles, out of which 48 potentially appropriate articles were reviewed. Of these 48 articles, 41 articles were included in the review. These articles were published between 2002 and 2016. Out of these 41 studies, 17 reported analysis of the serotonin transporter (SERT) gene (SLC6A4), eight on guanine nucleotide-binding protein subunit beta-3 (GNbeta3), six on the serotonin type 3 receptor genes (HTR3A), four on (HTR3E), three on (HTR2A), three the tumor necrosis factor superfamily member TL1A gene (TNFSF15), and ten on genetic polymorphisms with limited evidence.

CONCLUSION

Current evidence for the relation between genetic polymorphisms and IBS is limited owing to the fact that high-quality prospective studies and detailed phenotyping of patients suffering from IBS and matched controls were lacking in the past.

Keywords: Irritable bowel syndrome, Gene, Genetic polymorphisms

Core tip: The main genetic polymorphisms encountered in irritable bowel syndrome (IBS) are: Serotonin transporter (SERT) gene (SLC6A4), guanine nucleotide-binding protein subunit beta-3 (GNbeta3), serotonin type 3 receptor genes (HTR3A), (HTR3E), (HTR2A), the tumor necrosis factor superfamily member TL1A gene (TNFSF15). We performed a review of existent data, that studied genetic polymorphisms in IBS patients. We found that the actual IBS subgroups are not sufficient in order to identify distinct phenotypes and further in leading to new guiding principles for treatment. This systematic review demonstrates the need for genetic studies with an increasing number of subjects, because contradictory findings in terms of IBS subtype have been reported.