青海藏族人群载脂蛋白B基因多态性的研究

Study on the polymorphisms of apolipoprotein B gene in healthy Tibetan population from Qinghai province

目的：了解藏族人群载脂蛋白B基因多态性的特点。方法：应用聚合酶链式反应首次研究了青海正常藏族人群（100例，男女各半）载脂蛋白B基因的可变数目串连重复序列（VNTR）及信号肽插入／缺失（Ins／Del）两个位点的多态性分布。结果：共检出20种VNTR等位基因，以HVE32等位基因（频率为0．27）最常见，其次为HVE34等位基因（频率为0．21）。该人群中信号肽的编码序列以Ins等位基因占优势，频率为0．745，Del等位基因频率为0．255。结论：青海藏族人群中的apoB基因VNTR多态性分布与汉族人群间存在差异，与西方白种人群比较VNTR和Ins／Del多态性的差异更为显著。提示东西方人种族之间存在各自的遗传恃点。

The present study aim at our understanding the polymorphism charac-terization of apolipoprotein B (apoB) gene in normal Tibetan population. Metbods: The polymor-phisms at two sites of signal peptide insertion (Ins) /deleti0n (Del) and 3' variable numeber tandemrepeats (VNTR)in apolipoprotein B gene were studied by using PCR in 1OO random normal individ-uals from Tibetan population respectively. Results: Twenty kinds of VNTR alleles were detected inthe subjects, HVE32 (allele frequency O. 27), one of the allele being most common in all of them,andsecondary common one being HVE34 (O. 2l). The distribution of VNTR small a1leles (HVE36) and big alleles ( HVE38) accounted for 83. 8%, l6. 2%respectively. Ins allele of Ins/De1 polymorphism of the signal peptide was a common one with re1ative frequency of O.0745, whileDel allele had the frequency of 0. 255 in these Tibetan people. There were not significant differ-ences of both allele (Ins, Del) frequencies between Tibetan male and female groups. Three geno-types formed by two alleles were Ins/Ins56. Ins/Del37 and Del/Del7, respectively. The relative fre-quencies of Ins/Del alleles were similar to those in Han nationality, but the frequency of Del allelesignificantly less than that of western Caucasian population (O. 34O, P<O. O5)' The fequency distri-bution of VNTR main alleles were significantly different from Han and western popula-tions. Coucluslon: The data of polymorphisms of signal peptide insertion/deletion and VNTR ofapoB gene from normal Tibetan were obtained. There were not only significant difference of VNTRpolymorphisms between Tibetan and Han nationality, but also much significant difference of VN-TR and Ins/Del polymorphisms among Tibetan and other western ethnical populations.