RESUMO
Objective To investigate the relationship between diarrhea-predominant irritable bowel syndrome (D-IBS) and HTR3A,HTR3E gene polymorphism in Yangzhou,Jiangsu province.Methods Polymerase chain reaction (PCR) amplification and restriction fragment length pdymorphism (RFLP) technique were used to detect the 5′-UTR variant c.-42C＞T of HTR3A and 3′-UTR variant c.* 76G＞A of HTR3E on 300 healthy subjects and 450 patients with D-IBS.Results There was significant difference noticed between the D-IBS patients and the controls in the genotype of c.-42C＞T sites (P＜0.05),while the frequency of T allele was significantly higher in both female and male patients than that in the controls (P＜0.05).The frequencies of G/A genotype and A allele of c.*76G＞A sites were significantly higher in the female-patient group than that in the controls (P＜0.05),however,there was no significant difference between those male patients and controls (P＞0.05).When comparing to the CC genetype of rs1062613 site and GG genetype of rs62625044 site,the TT and GA genotype were closely related to the D-IBS,with the risk coefficients as 0.29 (95％ CI:0.14-0.61) and 0.62 (95％ CI:0.39-0.99),with statistically significant differences.Conclusion T allele and GA genetype might respectively serve as the predisposing factors of D-IBS and on the female D-IBS patients.