Review
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World J Gastroenterol. Nov 21, 2008; 14(43): 6636-6640
Published online Nov 21, 2008. doi: 10.3748/wjg.14.6636
Genetic determination of irritable bowel syndrome
Cristina Hotoleanu, Radu Popp, Adrian Pavel Trifa, Laurentiu Nedelcu, Dan L Dumitrascu
Cristina Hotoleanu, Dan L Dumitrascu, 2nd Medical Department, University of Medicine and Pharmacy Iuliu Hatieganu, Cluj-Napoca 400 006, Romania
Radu Popp, Adrian Pavel Trifa, University of Medicine and Pharmacy Iuliu Hatieganu, Genetic Department, Cluj-Napoca 400 006, Romania
Laurentiu Nedelcu, Department of Internal medicine, University Transilvania Brasov, Cluj-Napoca 400 006, Romania
Author contributions: Hotoleanu C designed research and wrote the paper; Popp R, Trifa AP and Nedelcu L performed literature review; Dumitrascu DL suggested the subject and revised the paper.
Correspondence to: Dan L Dumitrascu, Professor, 2nd Medical Department, University of Medicine and Pharmacy Iuliu Hatiegau, Str Clinicilor 4, Cluj-Napoca 400 006, Romania. ddumitrascu@umfcluj.ro
Telephone: +40-722-756475 Fax: +40-264-593355
Received: March 23, 2008
Revised: May 10, 2008
Accepted: May 17, 2008
Published online: November 21, 2008
Abstract

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder. According to the Rome III criteria, IBS is defined as recurrent abdominal pain or discomfort for at least 3 d per month during the previous 3 mo associated with two or more of the following symptoms: improvement with defecation, onset associated with a change in the frequency of stool and/or onset associated with a change in form or appearance of stool. There is growing evidence regarding the genetic contribution in IBS, however the precise etiology of IBS is still unknown. The evaluation of the genetic influence is based on twin studies, familial aggregation and genetic epidemiological investigations. Most studies showed a concordance for IBS significantly greater in monozygotic than in dizygotic twins. The majority of the studies have shown that familial aggregation may represent exposures to a similar environment, as well as the influence of genetic factors. Whereas no specific gene has been identified in association with IBS, recent studies have noticed the importance of polymorphisms in the promoter region of the serotonin reuptake transporter gene, G-protein beta 3 subunit gene (C825T), cholecystokinin receptor (CCKAR gene 779T>C), and high-producer tumor necrosis factor genotype. Further studies are necessary to determine how genetic factors influence the clinical manifestations and therapeutical response in IBS patients.

Keywords: Irritable bowel syndrome; Genetic factors; Gene polymorphisms; Twin studies; Familial aggregation