心肌梗死患者载脂蛋白B基因多态性

The Apolipoprotein B Gene Polymorphisms in Myocardial Infarction Patients

为研究载脂蛋白Ｂ基因多态性与动脉粥样硬化的关联，选择健康体检者８４人和确诊为心肌梗死患者８４人为对象，进行载脂蛋白Ｂ基因多态性的研究。用聚合酶链反应检测心肌梗死患者和正常人的载脂蛋白Ｂ基因上３个位点的遗传多态性标记，结果显示，心肌梗死患者组载脂蛋白Ｂ基因上的ＸｂａＩ酶切位点上Ｘ＋等位基因相对频率明显高于正常组（Ｐ＜０．０５）。而ＥｃｏＲＩ和ＭｓｐＩ酶切位点的Ｅ＋和Ｍ＋等位基因相对频率与正常人组无明显差异（Ｐ＞０．０５）。以上结果提示ＸｂａＩ与心肌梗死有关联，而Ｅ＋和Ｍ＋等位基因与心肌梗死之间可能无内在关联。

Aim To study on the three polymorphic sites of apolipoprotein B gene Ecoli, Mspl and Xbal and their association with atherosclerosis in Chinese Han nationality. Methods Subjects were 84 patients of myocardial infraction (MI) and 84 normal matched controls. Polymorphisms of apo B gene were determined by using polymerase chain reaction technique. The plasma lipid were performed, TC were measured by enzymatic method, TG were measured by ethylene acetone micro method, HDLC was determined after phosphotungstate precipitation, LDLC was measured by polyvinyl sulfate precipitation method, apoAI and apo B were quantified by immunonephrometry and the determination of Lp(a) was performed with ELISA (enzyme linked immunosorbent assay). Results In Chinese Han population, the appearance of E+ and M- were frequent ones at EcoRI and MapI restriction sites in apoB gene (the frequencies were 0.945 and 0.969 respectively); comparatively, relative frequencies of E- and M+ alleles were only 0.056 and 0.081 respectively, which were significantly lower than in the White. The relative frequency of X+ allele at Xbal restriction site in apoB gene was significantly higher in the MI group than that in the control group ( the frequencies were 0.0774 and 0.0297,(P<0.05). The levels of TC, TG, LDLC, apoB, Lp(a) and the ratio of LDLC/HDLC, (TC-HDLC/HDLC) were significantly higher; and the level of HDLC, the ratio of apoAI/B were significantly lower in MI patients as compared with those of controls (P<0.05).The incidence of hyperlipidemia in MI group was 72% higher than control group (P<0.05), But the three polymorphic sites of apo B were not associated with the variation of the levels of lipid, lipoprotein and apolipoprotien. Conclusion The data suggested that allele of X+ at Xbal restriction sites in apoB gene was associated with susceptibility to coronary atherosclerosis.