Serotonin transporter gene polymorphism may be associated with functional dyspepsia in a Japanese population

Subjects were divided into either a postprandial distress syndrome (PDS) group or an epigastric pain syndrome (EPS) group according to the Rome III criteria. The healthy controls were those who had visited a hospital for an annual health check-up. The presence of the SLC6A4 promoter polymorphism, 5-hydroxytryptamin transporter gene linked polymorphic region (5-HTTLPR), was then evaluated, and logistic regression analysis was used to test all variables.The 5-HTTLPR genotype distribution was 448 SS, 174 SL, and 24 LL in controls and 30 SS, 20 SL, and 3 LL in FD subjects. No significant correlation was found between the 5-HTTLPR genotype and FD. When the genotypes and subtypes of FD were exploratory evaluated, the SL genotype was significantly associated with PDS [odds ratio (OR) = 2.24, 95% confidence interval (CI); 1.16-4.32, P = 0.034 after Bonferroni correction] compared to the SS genotype adjusted for sex and age. Comparison of the SS genotype with the SL/LL genotype also showed a significant association of genotype with PDS (OR = 2.32, 95% CI; 1.23-4.37, P = 0.009).The present results suggest that 5-HTTLPR L allele may influence the susceptibility to PDS.Functional dyspepsia (FD) is characterized by the presence of symptoms thought to originate in the gastroduodenal tract in the absence of any organic or systemic disease that explains the symptoms [1]. The precise pathophysiology of the functional gastrointestinal disorders is still unknown. However, several pathophysiological mechanisms have been described as possible etiological factors: visceral hypersensitivity [2,3], impaired proximal gastric accommodation [4], delayed or early gastric emptying [5], dysfunction of the autonomic nervous system [6], and underlying psychiatric disturbances [7]. Although risk factors for FD, including age, sex, Helicobacter pylori infection, smoking, and psychological disturbances, have also been reported, the data are inconclusive [8,9].There is increasing evidence that suscept