5-羟色胺转运体基因多态性与肠易激综合征的相关性

目的:探讨SERT基因启动子区5-HTTLPR和内含子2 VNTRs多态性在肠易激综合征(IBS) 中的意义．方法:采用PCR方法对51例腹泻型IBS(D- IBS)、58例便秘型IBS(C-IBS)、38例便秘腹泻交替型IBS(A-IBS)患者与48例健康对照者SERT基因启动子区5-HTTLPR和内含子2 VNTRs多态性进行比较分析．结果:C-IBS组L／L基因型及L等位基因频率显著高于对照组(31．0％vs 8．3％,X2=8．229, P<0．05;47．4％vs29．2％,X2=7．342,P<0．05), D-IBS组S／S基因型频率和S等位基因频率显著高于A-IBS和C-IBS组(S／S:56．9％vs 36．8％, 36．2％,P<0．05;S:71．6％vs 56．6％,52．6％, P<0．05),L／L基因频率显著低于A-IBS和C-IBS 组(9．8％vs 28．1％,P<0．05)．IBS各组与对照组之间内含子2 VNTRs多态性分布无显著性差异(P>0．05)．结论:具有L／L基因型和L等位基因的人更易患C-IBS,具有S／S基因型和S等位基因的人更易患D-IBS,L／L基因型可能是D-IBS的保护因素之一．

Relationship between serotonin transporter gene polymorphism and irritable bowel syndrome

AIM: To investigate the relationship between serotonin transporter gene polymorphism and irritable bowel syndrome (IBS). METHODS: Polymerase chain reaction (PCR) was used to comparatively analyze the polymorphisms of serotonin transporter gene 5-HTTLPR and VNTRs within intron 2 in patients with diarrhea-predominant IBS (D-IBS, n = 51), constipation-predominant IBS (C-IBS, n = 58), and alternating diarrhea and constipation IBC (A-IBS, n = 38) and healthy controls (n = 48). RESULTS: The frequencies of L/L genotype and L allele in C-IBS patients were significantly higher than those in the controls (31.0% vs 8.3%, X2 = 8.229, P < 0.05; 47.4% vs 29.2%, X2= 7.342, P < 0.05). The frequencies of S/S genotype and S allele in D-IBS patients were significantly higher than those in C-IBS and A-IBS patients (S/S: 56.9% vs 36.2%, 36.8%, P < 0.05; S: 71.6% vs 52.6%, 56.6%, P < 0.05), but the frequency of L/L genotype was markedly lower (9.8% vs 31.0%, 23.7%, P < 0.05). However, no significant difference was found in VNTRs polymorphism between the subgroups of IBS and controls (P> 0.05). CONCLUSION: The presence of L/L genotype and L allele probably increases the susceptibility of individuals to C-IBS, while S/S genotype and S allele probably increases that to D-IBS. L/L genotype may be a protective factor against D-IBS.