An international research team led by Ikerbasque Professor Mauro D’Amato, Head of the Gastrointestinal Genetics Group of the Osakidetza Biodonostia Health Research Institute has identified new genetic variants linked to the risk of suffering from Irritable Bowel Syndrome (IBS) in women. The results, published in the scientific journal Gastroenterology, may help to explain why IBS is more common in women than in men.

Irritable bowel syndrome is the most common gastrointestinal disorder in humans. More than 10% of the population suffer from recurring symptoms including abdominal pain, gas, diarrhoea and constipation, with a greater incidence in the female population. The factors leading to IBS are largely unknown, which is a major obstacle to the development of effective treatments for affected patients. However, while the genetic predisposition to suffer from IBS has been acknowledged, very little research has been carried out on this so far.

The international research team led by Professor D’Amato has recently identified DNA variants that are associated with an increased risk of suffering from IBS in cases involving women only.

Using genetic data from more than 300,000 participants from the United Kingdom Biobank in a genome wide association study (GWAS), DNA variants that are associated with an increased risk of being medically diagnosed with IBS in women but not in men were found. A region of chromosome 9 that also influences the onset of puberty for women (age when menstruation starts) was specifically identified.

Meanwhile, a follow-up to this finding carried out in 2,045 patients in specialised IBS sites in Sweden, Belgium, the Netherlands, Italy and the United States, researchers have found other links between IBS and constipation and harder stools that again was only found in women.

According to Mauro D’Amato, “Although it is too early to pinpoint individual genes, we think these results are very exciting in how they converge with existing data on its prevalence in women and the role of sex hormones in IBS.”

Apart from IIS Biodonostia, researchers and doctors from other institutions have also participated in the study, such as the Karolinska Institutet, the Mayo Clinic and the University of California Los Angeles in the United States, IKMB in Kiel, Germany,TARGID in Leuven, Belgium, the Universities of Bologna, Italy, Groningen and Maastricht in the Netherlands, to name a few.

The research has been funded by the Basque Government’s Department of Health, the Ministry of Economy and Competitiveness (ISCIII), the Swedish Research Council (VR), the NIH, USA and the FP7 from the EU (BBMRI-LPC).


Female-specific Association Between Variants on Chromosome 9 and Self-reported Diagnosis of Irritable Bowel Syndrome

Ferdinando Bonfiglio, Tenghao Zheng, Koldo Garcia-Etxebarria, Fatemeh Hadizadeh, Luis Bujanda, Francesca Bresso, Lars Agreus, Anna Andreasson, Aldona Dlugosz, Greger Lindberg, Peter T. Schmidt, Pontus Karling, Bodil Ohlsson, Magnus Simren, Susanna Walter, Gerardo Nardone, Rosario Cuomo, Paolo Usai-Satta, Francesca Galeazzi, Matteo Neri, Piero Portincasa, Massimo Bellini, Giovanni Barbara, Anna Latiano, Matthias Hübenthal, Vincent Thijs, Mihai G. Netea, Daisy Jonkers, Lin Chang, Emeran A. Mayer, Mira M. Wouters, Guy Boeckxstaens, Michael Camilleri, Andre Franke, Alexandra Zhernakova, Mauro D’Amato.