人类单纯性先天性心脏病患者Nkx2—5基因突变及表达的研究

目的：研究Nkx2-5基因在人类单纯性先天性心脏病患者中的突变及表达情况。方法：应用PCR－SSCP方法和NDA测序技术在58个单纯性先天性心脏病核心家系183名成员中检测Nkx2-5基因的突变情况；以β－actin作为内对照对11个室间隔缺损患者心肌标本和2个非先天性心脏病患者（正常对照）心肌标本进行RT－PCR扩增和定量分析，观察mRNA表达水平。结果：发现Nkx2-5基因同源结构域中（CCA）三碱基缺失；与非先天性心脏病患者（正常对照）相比，室间隔缺损患者的Nkx2-5基因基因mRNA表达呈下降趋势。结论：Nkx2-5基因与人类单纯性先天性心脏病密切相关，其同源结构域内的基因突变可能是人类单纯性先天性心脏病发病的重要遗传基础。Nkx2-5基因转录水平的异常可能是先天性心脏病形成的另一种潜在机制。

Mutation and Expression of Nkx 2-5 Gene in Human Simple Congenital Heart Disease

Objective: Our purpose was to detect the mutation and expression of Nkx 2 5 gene. Methods: We used PCR SSCP method and genetic analyzer to detect the mutations of Nkx 2 5 gene in 58 congenital heart disease families. We also applied RT PCR and the quantitative analysis to detect the differential expression between 11 ventricular septal defect samples and 2 healthy controls (one was rheumatic heart disease, and the other was cardiac myxoma in the left atrium). Results: We found a deletion of 3 base pair (CCA) in the homodomain region of Nkx 2 5 gene, and the expression of Nkx 2 5 gene in most ventricular septal defect samples decreased compared with the healthy controls. Conclusion: This is the first time to find the 3bp deletion of Nkx 2 5 gene in human congenital heart disease, and mutations in the homodomain region of Nkx 2 5 gene may be an important genetic basis for the pathogenesis of human simple congenital heart disease. The abnormal expression of Nkx 2 5 gene on mRNA level might be another kind of mechanism for the formation of congenital heart disease.