应用聚合酶链反应研究载脂蛋白B基因多态性及其临床意义

The study of apolipoprotein B gene polymorphisms by using polymerase chain reaction

应用聚合酶链反应（ＰＣＲ）对１００例正常人及１０３例冠心病人载脂蛋白Ｂ（ａｐｏＢ）基因ＸｂａＩ和ＥｃｏＲＩ限制性片段长度多态性（ＲＦＬＰ＿Ｓ）研究表明：（１）此两个位点上少见等位基因（Ｘ￣＋和Ｅ￣－）相对频率在冠心病组中均明显高于正常对照组，提示这些基因多态性与冠心病发病有一定关联。（２）ＸｂａＩ位点上具Ｘ￣＋Ｘ￣－基因型含血浆ＨＤＬ—Ｃ水平明显低于相应的Ｘ￣－Ｘ￣－基因型者，可能为Ｘ￣＋等位基因与冠心病关联的机理之一。（３）ＸｂａＩ和ＥｃｏＲＩ两位点的多态性间无连锁不平衡，推测这些位点的多态性以各自独立的方式影响动脉粥样硬化的形成。（４）ＰＣＲ方法用于ａｐｏＢ基因多态性的研究具有简便、敏感、重复性好、可判性强等优点，值得推广应用。

wo polymorphic sites of apolipoprotein B(apoB)gene──XbaI and EcoRI──were examined in a sample of 103 patients with documented coronary heart disease(CHD)and 100 healthy individuals.It was demonstrated:(1)The frequencies of rare X￣+allele(presence of XbaI cutting site) and E allele(absence of cutting site) were significantly higher in CHD patients than those in controls.It was sug-gested that these genetic variations were associated with CHD.(2)The patients with genotype of X￣+X￣-had significantly lower HDL-C level than those with genotype of X￣-X￣-in the CHD group. This probably accounted for one of the mechanisms by which X￣+allele was associated with CHD.(3)There seemed no linkage disequilibrium between XbaI RFLP and EcoRI RFLP. It was hypothesized that the polymorphisms at these two sites influenced atherosclerosis by their indepel1dent ways.(4) Applied in the study of the apo B gene polymorphisms, PCR method possessed such advantages as simplicity, high sensitivity and high specificity.It deserves spreading application.