Norwegian researchers found that patients with functional colopathy and those with psychiatric disorders shared genetic variants.
- Using new statistical methods, scientists have successfully identified 116 new genomic risk loci for irritable bowel syndrome.
- 70 unique loci shared between functional colopathy and different psychiatric disorders (anxiety, depression, bipolarity, schizophrenia) were found.
- Several loci linked to irritable bowel syndrome are involved in the regulation of the nervous and immune systems.
Irritable bowel syndrome (IBS), also known as functional colopathy, is a disease that affects approximately 5% of the French population. As a reminder, the symptoms of this pathology include abdominal pain, bloating, diarrhea or constipation. Additionally, it has been observed that irritable bowel syndrome often coexists with psychiatric disorders, such as anxiety, depression, and bipolar disorder.
Studying the genetic overlap between IBS and psychiatric disorders
Until now, studies of functional colopathy have focused on environmental factors and physiological mechanisms, but little attention has been paid to the genetic component of this disease. “Recent research has identified several genetic risk variants for irritable bowel syndrome. However, most of the heritability remains unidentified and the genetic overlap with psychiatric and somatic disorders is not quantified,” said scientists from the universities of Bergen and Oslo in Norway.
Therefore, they decided to conduct work to further examine the genetic overlap between irritable bowel syndrome and psychiatric and gastrointestinal phenotypes. As part of their study, the researchers used data from 53,400 people with irritable bowel syndrome and 433,201 controls. For the purposes of their research, they also used new statistical methods to analyze genetic correlations.
35 unique loci shared between functional colopathy and depression
“We found extensive polygenic overlap between irritable bowel syndrome and psychiatric disorders and, to a lesser extent, gastrointestinal diseases,” can we read in the results published in the journal Genome Medicine. In detail, the authors identified 116 new genomic loci (i.e. specific locations in the DNA sequence often including a group of variants) at risk for functional colopathy. Additionally, they detected 70 unique loci shared between irritable bowel syndrome and different psychiatric disorders: 7 with anxiety, 35 with depression, 27 with bipolar disorder, and 15 with schizophrenia.
“Functional analyzes of shared loci revealed enrichment of biological pathways in the nervous and immune systems,” explained the team. Clearly, many loci linked to functional colopathy are also involved in the regulation of the nervous system. The study’s lead author, Markos Tesfaye, hopes that these results can launch experimental research, which could in turn lead to the development of treatments for irritable bowel syndrome.
