目的检测中国汉族人群胰岛素降解酶(IDE)基因启动子区多态性与散发性阿尔茨海默病(SAD)的关系。方法随机选取25名SAD患者和25名正常对照者进行IDE启动子测序筛查启动子区变异。采用聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)方法对中国汉族412例SAD患者和331例正常对照者进行多态性分型,遗传统计学分析多态性与AD发病风险的关系。结果中国汉族人群中IDE启动子存在三个多态性位点,分别为-1002T/G、-179T/C和-51C/T,-1002T/G和-51C/T多态性的基因型和等位基因频率在SAD和正常对照组中有显著差异。-1002T和-51C在SAD组中明显多于正常对照组。在不携带APOEε4等位基因的亚组中,各基因型和等位基因的频率有显著性差异。-1002T/G和-51C/T存在显著的连锁不平衡,构成了相对增加AD发病风险的单体型-1002T/-51C和相对保护的单体型-1002G/-51T。结论 IDE启动子区-1002T/G和-51C/T多态性与中国汉族人群SAD的发病相关。
Objective To detect the association between promoter polymorphisms of insulin-degrading enzyme(IDE)gene and the risk for sporadic Alzheimer's disease(SAD)in Chinese Han population.Methods We sequenced the proximal IDE promoter in 25 randomly selected controls and 25 SAD patients to detect variations in these regions.Using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP)we genotyped these polymorphisms of 412 SAD patients and 331 healthy controls in Chinese Han population.By genetic statistical assay,we study the association between these polymorphisms and the risk for SAD.Results We found three polymorphisms in IDE promoter which were-1002T/G,-179T/C and-51C/T.For-1002T/G and-51C/T,there were significant differences in genotype and allele frequencies between SAD and control.-1002T and-51C alleles were over represented in SAD patients compared with those in controls.In the subjects without APOEε4 allele,these differences remain significant.We found that-1002T/G and-51C/T were in strong linkage disequilibrium.The-1002T/-51C haplotype was a possible risk factor of AD,while-1002G/-51T was relatively protective.Conclusion-1002T/G and-51C/T polymorphisms in the proximal IDE promoter are associated with SAD in Chinese Han population.