血浆脂蛋白a Apo（a）结构基因基因多态性与颅内动脉瘤的相关性

目的：探讨血浆脂蛋白（a）[Lp（a）]及载脂蛋白（a）[Apo（a）]结构基因（APOA）5’调控区PNR基因多态性与颅内动脉瘤发病的相关性。方法：选择经颅脑CTA、DSA及手术证实为颅内动脉瘤的45例患者和健康对照组45例,测定其血浆Lp（a）的浓度;同时采集其血浆,提取白细胞基因组DNA,采用聚合酶链式反应-限制性片段长度多态性（PCR-RFLP）结合非变性聚丙烯酰胺凝胶电泳（PAGE）等方法,检测载脂蛋白（a）的结构基因5’调控区-1500位点五核苷酸重复序列的多态性（PNR）[（TTTTA）n]基因多态性。结果：动脉瘤组Lp（a）平均浓度为（50.2±14.3）mg/dl,健康对照组为（14.9±7.6）mg/dl（P〈0.001）;两组研究对象Apo（a）结构基因的PNR共检测出8种基因型和5种等位基因,动脉瘤组PNR-5等位基因频率和PNR5/8基因型频率显著高于健康对照组;且重复序列为5的等位基因还与血浆Lp（a）升高相关（P〈0.05）。结论：血浆Lp（a）浓度与颅内动脉瘤发病有显著相关性;ApoaPNR（TTTTA）拷贝数为5的等位基因可能与颅内动脉瘤发生呈正相关。

The Correlation between Plasma Lipoproteins(a) Levels Polymorphism of Apolipoprotein(a) Gene and Intracranial Aneurysms

Objective：To study the correlation between Lipoproteins（a） level and pentanucleotide repeats（PNR）,polymorphism in the 5＇ untranslated region of the apolipoprotein（a） gene and intracranial aneurysms.Method：The cases were divided into 2 groups：45 patients with intracranial aneurysms and 45 healthy controls.The Lp（a） levels were measured and compared.The PNR polymorphism of the apolipoprotein（a） gene were detected by using polymerase chain reaction-restriction fragment length polymorphism（PCR-RFLP） combining with non-denatured polyacrylamide gels electropherosis（PAGE）.Result：Plasma Lp（a） leval in the patients was（50.2±14.3）mg/dl,while that in the control subjects was （14.9±7.6）mg/dl（P0.001）.8 kinds of PNR gene types and 5 kinds of alleles were detected.There was one site of sequence variance in the 5’control region of APOA gene,which was significantly different between the patients and controls.The allele frequency with 5 repeats was associated with high Lp（a） levels（P0.05）.Conclusion：Lp（a） is an independent risk factor for genesis of intracranial naeurysms.Correlation may exist between the polymorphisms in the 5＇ control region of the apolipoprotein（a） gene and the etiology and pathogenesis of intracranial aneurysms.