INTERNATIONAL RESEARCH WORK IDENTIFIES GENETIC FACTORS OF INFLAMMATORY BOWEL DISEASE

The magazine Nature published research work participated in by Mauro D’Amato, Ikerbasque Professor and Head of the Gastrointestinal Genetics group at IIS Biodonostia of Osakidetza. The study created a high-resolution map of genetic variations that play a role in causing the disease.

Inflammatory bowel diseases (IBD) are chronic inflammatory processes where alterations occur in the interaction between the immune system and intestinal microbiota in genetically susceptible individuals.

IBDs affect millions of people all over the world, and it is estimated that there are about 170,000 patients in Spain, with a rate that has been multiplied by 5 over the past 25 years, with about 5,000 new cases detected every year. In the Basque Country, it is calculated that 7,000 people are affected by it.

The exact causes of this disease are unclear, so currently there are no effective cures. Thus, for greater understanding of IBD’s underlying genetics, until now genome association studies have been conducted, and hundreds of human genome regions related to the disease have been found. However, prior research was unable to identify the genes and specific risk variations with certainty.

In this new study, recently published in the prestigious scientific magazine Nature, researchers identified the genes responsible for an increased risk of IBDs from a list of over 600 that are potentially involved in the disease. The work was conducted by an international team of scientists, with Mauro D’Amato, Ikerbasque Professor and head of the Gastrointestinal Genetics Group, integrated into the Hepatic and Gastrointestinal Disease Research Department at IIS Biodonostia of Osakidetza, led by Professor Luis Bujanda, participating.

This international team, formed by different institutions, including the Wellcome Trust UK, Broad/MIT from Harvard and the GIGA from the University of Lieja, made efforts to make a high-resolution map to research which genetic variations play a role in causing the combined disease.

To this end, they studied the genome of 67,852 people and applied three different statistical methods to verify which genetic variations are actively involved in the disease. Of all the genes associated with IBDs studied, in 18, with a certainty level above 95 percent, the genetic variation responsible for increasing the risk of IBDs was identified. These results are a foundation to individualise treatment for this disease, as well as to discover new pharmacological targets.

In short, the information from this kind of study can be used in different stages: in diagnosis, to help with early identification of at-risk individuals, especially in families with affected members; in the prognosis, if the risk variations also have a predictive value for the disease’s clinical course, and in response to treatment, if therapeutic efficacy is influenced by several of these specific variations, and patients can be therefore be stratified for personalised cure.

Lastly, in addition to progress from a scientific perspective and in improving treatment for those affected, the impact this progress can have on the healthcare system is remarkable, given that personalised prevention and treatment can have a long-term effect on decreasing healthcare costs stemming from hospital stays, operations, care, etc.