中国汉族和蒙古族人群载脂蛋白B基因3'端高可变区等位基因的分布频率及序列分析

载脂蛋白Ｂ基因３’末端下游有一个高可变串连重复序列（ｖａｒｉａｂｌｅｎｕｍｂｅｒｏｆｔａｎｄｅｍｌｙｒｅｐｅａｔ，ＶＮＴＲ），也叫高可变区。每一个串连重复序列长度在１５ｂｐ左右，富含Ａ、Ｔ两个核苷酸，不同的串连重复序列拷贝数构成了等位基因的高度多态性。本文应用ＰＣＲ技术分析了汉族和蒙古族人群载脂蛋白Ｂ基因３＇ＶＮＴＲ等位基因的分布和频率；并测定了等位基因ＨＶＥ３４和ＨＶＥ４６的核苷酸序列。在汉族人群（１６４例冠心病患者，１３６例正常人）中共分离到１４个３’ＶＮＴＲ等位基因，以ＨＶＥ３６的分布频率（３１．４％）最高，其次是ＨＶＥ３４，约占２４．０％，而从６１例蒙古族正常人本课题系攀登计划”与“

The Distributions and Sequencing of Apo B Gene 3'-Variable Number of Tandemly Repeat Alleles in Chinese Han and Mongolian Nationalities

In this paper,the allelic distributions of apo B gene 3'-variable number of tandemly repeat(VNTR)in Chinese Han and Mongolian nationalities were alalyzed by PCR techniqe. The nucleotide acids of HVE34 and HVE46 were sequencied by automatic Ma chine AB1373A Model.The results showed that 14 al leles in the samples of 300 Han individuals(164 cases of patients with coronary heart disease and 134 normal matched subjects) and 12 alleles in the samples of 61 Mongolian individuals. In Han nationalit y group,the most common allele is a repeat unit allele (HVE36),occupied 31% of the total alleles. HVE34 and HVE32 are 24%and 22%respectively. In comparison with Han nationality,the most common allele in Mongolian nationality group is HVE34,occupied 35.2%. HVE36and HVE32 are 28.7%and 13.9%respectively.Futhermore,we also found that the alleles of homozygote(80%)in Mongolian group are much higher than that(52%)of Han nationality group. No alleles less than HVE30 was found in the Mongolian group. The amplication products of homozygotes of HVE 34 and HVE46 alleles were directly aequenced. It was found that the 3' hypervariable region apo B gene consists primarily of a 15 bp basic repeat unit called X and Y sequence and tandemly repeat in an X-Y Order. The ATrich region also contains variants of X and Y sequences resulted from C or G for A substitution. The length of different alleles was ditermined by the numbers of X and Y copies. The HVE polymorphism of apo B gene not only resides in the variable numbers of repeat units,but also resides in the variation in the oligonucleotide sequence within the repeat units as well as the variation in the arrangement of the repeat.