昆明汉族人群D21S1411、IFNAR位点多态性及其在Down综合征基因诊断中的应用价值  

Genetic Polymorphism of Two STR Loci in Kunming Han Population and Its Application in Gene Diagnosis for Down Syndrome

作　　者：刘娟[1] 朱宝生[2] 梁文通[1] 张红云[1] 谭宗建[1] 

机构地区：[1]贵州省人民医院生殖医学中心,贵阳550002 [2]云南省第一人民医院遗传诊断中心 ,昆明650032

出　　处：《国际遗传学杂志》2008年第1期5-8,共4页International Journal of Genetics

摘　　要：目的调查昆明汉族人群第21号染色体上D21S1411和IFNAR两个短串联重复序列（short tandem repeat，STR）的遗传多态性，探讨这两个STR基因座在Down综合征基因诊断中的应用价值。方法随机抽取100名昆明地区无血缘关系汉族正常个体及2名Down综合征患者的静脉血，应用PCR技术扩增D21S1411和IFNAR位点的STR片段，采用聚丙烯酰胺凝胶电泳、硝酸银染色分型，结合图像分析系统测定等位基因片段大小。结果昆明汉族人群D21S1411和IFNAR等位片段数分别为6个和7个；2个位点的基因型分布均符合Hardy-Weinberg平衡；各位点杂合度分别为0．87、0．82，多态信息含量分别为0．8062、0．8365。在IFNAR位点上，2例Down综合征患者，均出现DNA含量为2：1的2条带；在D21S1411位点上，1例出现DNA含量为1：1：1的3条带，1例出现2：1的2条带。结论D21S1411、IFNAR是两个多态信息含量比较高的基因座，在法医学及Down综合征基因诊断中具有较高的应用价值。Objective To investigate the genetic polymorphism of two STR loci on chromosome 21 in Kunming Han population as well as its application in DNA testing for Down syndrome. Methods The genomie DNA extracted from 100 unrelated individuals of Han nationality in Kunming and 2 Down syndrome patients were amplified by PCR technique. The PCR products were analyzed using polyacrylamide gel electrophoresis （PAGE） , followed by silver staining. And the ＇allele size was detected by Image Analysis System. Results Six alleles were found at D21S1411 locus, seven alleles at IFNAR locus in Kunming Han population. All the 2 loci accord with Hardy-Weinberg equilibrium. The heterozygosities were 0.87, 0.82 and the polymorphic information contents were 0. 8062 and 0. 8365 for D21S1411 aed IFNAR , respectively. At IFNAR locus, 2 Down syndrome patients showed two bands with a ratio of 2： 1. At D21S1411 locus 1 case showed three bands with a ratio of 1： 1： 1, and 1 case showed two bands with a ratio of 2： 1. Conclusion D21S1411 and IFNAR are two high polymorphic information content（PIC） loci. These two loci are valuable genetic markers in dividual identification ,partenity test in forensie area and the molecular diagnosis for Down syndrome.

关 键 词：短串联重复序列 遗传多态性 DOWN综合征 基因诊断 

分 类 号：D919[医药卫生—法医学]