新疆维汉两民族缺血性脑卒中叶酸代谢通路基因稀有及常见变异的高通量测序研究

Homocysteine (HCY) is the crucial metabolin of folacin metabolic pathways and its level is a independent predictor of ischemic stroke (IS). The hereditary variation of this pathway related genes affected the occurrence of IS, but its pathogenic mechanism is still not clear. This research bases on the partly established sample library of IS cases and controls of Chinese Han and Uygur. We use the Solexa system for identifying clearly the association between frequency of genetic variation of folacin metabolic pathway related 11 genes and IS in Chinese Han and Uygur, and the level of HCY. This study is divided into two phases (total samples are about 3,600): (1)Discovery. We will sequence all about 11 genes of folacin metabolic pathways in 300 pairs of cases and controls respectively by the Solexa Platform (the total length is about 350 Kb/individual), determine the HCY level, screen and describe systematically the characteristics of different frequeny genetic variation. Furthermore, we will carry on interrelation analysis of locus, IS, and HCY level, and perform haplotype-based association studies, and genetic-environment interaction analysis (especially the analysis between alterable action, smoking for instance, and heredity). (2) Verification. We will validate the positive loci with frequency equal or greater than 3% in 600 pairs of Han and Uygur cases, respectively, and perform the meta-analysis of all samples. This research helps to understand deeply the relationship between folacin metabolic pathways related genes and IS and provide some clues for target prevention of group with specific genetic and behavior combination.

同型半胱氨酸（HCY）是叶酸代谢通路中的重要产物，其水平是缺血性脑卒中（IS）的独立预测因子，有研究显示叶酸代谢通路基因遗传变异与IS发生相关，但致病机制仍不清楚。本研究拟在已部分建立的新疆维族和汉族IS病例对照标本库基础上，采用新一代Solexa测序平台，系统研究叶酸代谢通路11个基因各种遗传变异在新疆维族、汉族IS发生及HCY水平中的作用。研究分两阶段（总量约3600例）：①发现阶段：对维族、汉族IS病例及对照各300对进行11个基因全序列测定（总长度350K/个体），同时测定HCY水平，系统筛查和描述各类突变特征、进行位点与IS及HCY水平的关联分析及遗传环境互作（尤其是遗传与吸烟等可改变行为）分析；②验证阶段：对频率≥3%的阳性位点在维汉各600对病例对照样本中验证，并进行荟萃分析。研究有助于增加对叶酸代谢通路基因与IS关系的认识，并为特定遗传和行为组合人群开展针对性预防提供线索。

缺血性脑卒中又称为脑梗死（Ischemic Stroke, IS），是最常见的脑卒中类型，占全部脑卒中的60％到80％，是全球第二大致死性疾病，在中国排首位。本项研究采用病例对照研究，选择与IS发病相关的多个遗传基因的49个位点，分别在汉族与维吾尔族人群两个人群中进行研究，为脑卒中的预防和治疗提供一定的理论依据。本研究发现：1）： MTHFR基因rs1801131多态性影响维吾尔族人群缺血性脑卒中的发生，C等位基因可能是维吾尔族发生缺血性卒中的的危险因素,MTRR基因rs2287780位点T等位基因可能是汉族人群中的保护因素;2)IL6基因rs1524107多态性影响维吾尔族人群缺血性脑卒中的发生,T等位基因可能是维吾尔族发生缺血性卒中的保护因素；rs2069840多态性影响维吾尔族人群缺血性脑卒中的发生，G等位基因可能是维吾尔族发生缺血性卒中的危险因素rs1800796多态性影响维吾尔族人群缺血性脑卒中的发生，C等位基因可能是维吾尔族发生缺血性卒中的保护因素；3）PCSK9基因rs11206510位点C等位基因、rs2479409位点GG基因型，可能是维吾尔族人群发病的危险因素，汉族人群中没有发现这种关联；4）HMGCR基因rs12916位点T等位基因可能是维吾尔族人群脑卒中发病的危险因素；5）TIMD4-HAVCR1基因s1501908位点C基因是维吾尔族脑卒中发病的保护因素；6）MMP12基因rs660599位点TT基因型是汉族人群中发病的保护因素，针对维吾尔族人群的研究并没有发现这种关联；7）ALDH2基因rs671位点A等位基因的携带（AA/AG）是汉族人群的保护因素，在维吾尔族人群中并没有发现这种关联。