哈萨克族人血管紧张素原基因-164-+73区域DNA变异及不同变异对血压的影响

DNA variants in the-164 to +73 region of angiotensinogen gene in Kazakhs and the effect of different variants on blood pressure

目的:检测哈萨克族人血管紧张素原(AGT)基因-164-+73区域DNA变异的位点和种类,并研究这些变异与原发性高血压(EH)的关系。方法:采用随机抽样的方法,选择生活在新疆牧区、年龄在30～60岁的哈萨克族人为研究对象。入选EH患者355例,正常血压者224例。收集表型资料和血标本,检测血脂等生化指标。采用蛋白酶K消化,饱和酚/氯仿抽提法提取白细胞基因组DNA,针对AGT基因-164-+73区域进行特异PCR扩增,运用SSCP、RFLP、基因克隆、基因测序等分子生物技术检测特异PCR产物中存在的DNA变异的位点、种类以及不同变异位点在该人群中存在的基因型组合类型,并比较不同基因型组合频率在EH组和正常对照组人群的分布以及不同基因型组合人群的血压水平。结果:①在哈萨克族人AGT基因-164-+73区域仅发现(-6)A-G、(-20)A-C2种变异,而不存在(-18)C-T、(-46)T-A2种变异。②在哈萨克族人群中,AGT基因-164-+73区域(-6)A-G、(-20)A-C2种变异存在6AG/-20AC、-6GG/-20AA、-6AA/-20AC、-6AG/-20AA、-6AA/-20AA、-6AA/-20CC6种基因型组合,而不存在(-6)GG(-20)CC、(-6)GG(-20)AC、(-6)AG(-20)CC3种组合。③6种基因型组合的构成在EH组和正常血压组人群中的差异有统计学意义(P<0.05)。④不同基因型人群的收缩压、舒张压水平中的差异有统计学意义(P<0.05),其中以带有纯合变异的基因型血压为最高,其次是同时带有2种变异的杂合基因型组。结论:哈萨克族人AGT基因-164-+73区域存在的(-6)A-G、(-20)A-C2种变异可能与EH的发生有关。

Objective： To detect the DNA variants in the -164 to ＋ 73 region of Kazakhs＇angiotensinogen （AGT） gene and research the effect of variations on essential hypertension. Method： Kazakhs who were 30 to 60 years old in pasturing area of Xinjiang were selected as research objects. Individuals including 355 hypertensives and 224 normotensives were enrolled in the study. Genomic DNA from leukocytes was analyzed for the locus and varieties of DNA variants in the -164 to ＋73 region of AGT gene by polymerase chain reaction （PCR）, single strand conformation polymorphism （SSCP）, restriction fragment length polymorphism （RFLP）, gene clone and automatic sequencing and so on. Result： ① There were only A（- 6）G and A（-20）C variants in the -164 to ＋ 73 region of Kazakans＇AGT gene. ②Only six kinds of genotype combinations were found in A（-6）G and A（-20）C locus, including -6AA/-20CC, 6AG/- 20AC, - 6GG/- 20AA, - 6AA/- 20AC, - 6AG/- 20AA, - 6AA/- 20 AA , not （ - 6 ） GG（ -20） CC, （ - 6） GG（ - 20） AC and（ - 6 ） AG（ - 20 ） CC. ③Significant difference was observed in the distribution of six kinds of genotype combinations between hypertensive and normotensive groups （P〈 0.05）.④There was also distinct difference at the levels of systolic and diastolic blood pressure between different genotype combination groups and the higher level of blood pressure was found in the groups with one or two kinds of homozygous variants, following heterozygous genotype combination groups. Conclusion：The results suggest that the polymorphism of A（-6）G and A （-20）C variants in 5＇upstream core promoter of the AGT gene might involve in the pathogenesis of essential hypertension in Kazakhs.