Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 7, 2015; 21(25): 7672-7682
Published online Jul 7, 2015. doi: 10.3748/wjg.v21.i25.7672
Gene polymorphisms associated with functional dyspepsia
Anastasia Kourikou, George P Karamanolis, George D Dimitriadis, Konstantinos Triantafyllou
Anastasia Kourikou, George D Dimitriadis, Konstantinos Triantafyllou, Hepatogastroenterology Unit, Second Department of Internal Medicine and Research Institute, Attikon University General Hospital, Medical School, Athens University, 12462 Haidari, Greece
George P Karamanolis, Academic Department of Gastroenterology, Laiko General Hospital, Medical School, Athens University, 11527 Athens, Greece
Author contributions: Kourikou A searched the literature, drafted and finally approved the manuscript; Karamanolis GP and Dimitriadis GD reviewed the draft and finally approved the manuscript; Triantafyllou K conceived the idea, reviewed the draft and finally approved the manuscript.
Conflict-of-interest statement: Authors have nothing to declare.
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:
Correspondence to: Konstantinos Triantafyllou, Assistant Professor, Hepatogastroenterology Unit, Second Department of Internal Medicine and Research Institute, Attikon University General Hospital, Medical School, Athens University, Rimini 1, 12462 Haidari, Greece.
Telephone: +30-210-5832087 Fax: +30-210-5326422
Received: February 23, 2015
Peer-review started: February 25, 2015
First decision: March 26, 2015
Revised: April 7, 2015
Accepted: May 21, 2015
Article in press: May 21, 2015
Published online: July 7, 2015

Functional dyspepsia (FD) is a constellation of functional upper abdominal complaints with poorly elucidated pathophysiology. However, there is increasing evidence that susceptibility to FD is influenced by hereditary factors. Genetic association studies in FD have examined genotypes related to gastrointestinal motility or sensation, as well as those related to inflammation or immune response. G-protein b3 subunit gene polymorphisms were first reported as being associated with FD. Thereafter, several gene polymorphisms including serotonin transporter promoter, interlukin-17F, migration inhibitory factor, cholecystocynine-1 intron 1, cyclooxygenase-1, catechol-o-methyltransferase, transient receptor potential vanilloid 1 receptor, regulated upon activation normal T cell expressed and secreted, p22PHOX, Toll like receptor 2, SCN10A, CD14 and adrenoreceptors have been investigated in relation to FD; however, the results are contradictory. Several limitations underscore the value of current studies. Among others, inconsistencies in the definitions of FD and controls, subject composition differences regarding FD subtypes, inadequate samples, geographical and ethnical differences, as well as unadjusted environmental factors. Further well-designed studies are necessary to determine how targeted genes polymorphisms, influence the clinical manifestations and potentially the therapeutic response in FD.

Keywords: Functional dyspepsia, Gene polymorphism, Genetic susceptibility, Pathophysiology

Core tip: Functional dyspepsia is a common disorder with complex pathophysiology. Recent evidence has shown that certain gene polymorphisms might be implicated in its pathogenesis; however, results are inconsistent. Further studies are required to develop new data that provide novel insights regarding the mechanisms of genetic susceptibility in functional dyspepsia.