G protein β3 subunit polymorphism and long-term prognosis of functional dyspepsia

Background/Aims: A link between G protein β3 (GNB3) polymorphism and functional dyspepsia (FD) has been suggested. The aim of this study was to determine the role of GNB3 polymorphism in the long-term prognosis of FD in Koreans. Methods: FD patients and normal healthy controls were recruited from patients who visited our center between December 2006 and June 2007. All of the subjects completed Rome III questionnaires before undergoing upper gastrointestinal endoscopy and colonoscopy. Genomic DNA was extracted for GNB3 genotyping. After 5 years, the subjects were reevaluated using the same questionnaires. Results: GNB3 825T carrier status was significantly related to FD in Koreans (p=0.04). After 5 years, 61.0% of the initial FD patients and 12.2% of the initial normal subjects were diagnosed with FD (odds ratio [OR], 11.7; 95% confidence interval [CI], 4.3 to 31.1; p<0.001). Regardless of the GNB3 genotype (p=0.798), female sex was strongly correlated with FD after 5 years (OR, 3.3; 95% CI, 1.2 to 9.1; p=0.017). Conclusions: The T allele of GNB3 is linked to FD in Koreans but does not predict long-term prognosis. Female sex is related to a higher prevalence of FD after 5 years.