Genes and functional GI disorders: from casual to causal relationship

Area of Science:

• Gastroenterology and Genetics

Background:

• Functional gastrointestinal disorders (FGID), including irritable bowel syndrome (IBS), significantly impact quality of life and healthcare systems.
• The etiology of FGID remains largely unknown, with current classification relying solely on symptom-based criteria.
• Genetic research offers potential for understanding FGID pathophysiology, but progress in IBS gene discovery has been limited.

Purpose of the Study:

• To summarize key findings and challenges in irritable bowel syndrome (IBS) gene discovery.
• To highlight the need for advanced genetic approaches in FGID research.

Main Methods:

• Review of existing genetic research in FGID and IBS.
• Discussion of the limitations of current gene discovery methods.
• Advocacy for hypothesis-free approaches such as genome-wide association studies (GWAS).

Main Results:

• Previous genetic studies in IBS have produced limited and often inconclusive results.
• No specific gene has been unequivocally identified as playing a pathogenetic role in IBS.
• Genome-wide association studies (GWAS) have not yet been extensively applied to FGID.

Conclusions:

• Robust and reproducible genetic findings in FGID require the adoption of powerful, hypothesis-free methods like GWAS.
• Concerted actions and adequate resources are essential for advancing FGID genetic research.
• Defining precise target phenotypes beyond symptom-based classification is a critical challenge for future studies.