20个STR基因座在湖南汉族人群中的遗传多态性

Genetic Polymorphism of 20 STR Loci in Hunan Han Population

目的对湖南汉族人群20个常染色体短串联重复序列(short tandem repeat,STR)基因座的等位基因分布、群体遗传学参数和邻近群体的遗传分析进行研究,评估其在法医学中的应用价值。方法应用Power-Plex21^(■) 试剂盒对2997例湖南汉族无关个体进行20个STR基因座复合扩增及等位基因分型,统计等位基因频率及群体遗传学参数,计算湖南汉族与已公开报道的13个群体间的Nei’s遗传距离,进行多维尺度分析并构建系统发生树。结果20个常染色体STR基因座的杂合度为0.6009~0.9116,个人识别能力为0.7745~0.9866,三联体非父排除率为0.2920~0.8191,二联体非父排除率为0.1910~0.7086,多态信息含量为0.5348~0.9093,基因型分布符合Hardy-Weinberg平衡。20个基因座的累积个体识别率为1-1.3509×10^(-21),三联体非父累积排除率与二联体非父累积排除率分别为0.999996523945999、0.999999996129773,基于湖南汉族人群与其他13个群体间遗传距离获得的多维尺度分析及系统发生树结果显示,其与湖北汉族相距较近,而与云南苗族最远。结论20个常染色体STR基因座在湖南汉族人群中呈高度多态性和良好的鉴别能力,能为该地区法医学个体识别、亲权鉴定和群体学研究提供基础数据。

Objective To investigate the allele distribution and population genetic parameters of 20 autosomal STR loci in Hunan Han population,and to analyze the data with those of neighboring populations,thus to evaluate their forensic application value.Methods The Power-Plex21^(■)system was used to perform multiplex PCR amplification and allelic gene typing of 20 STR loci in 2997 unrelated Han individuals from Hunan Province.Allele frequencies and population genetic parameters were calculated.The Nei’s genetic distances between Hunan Han population and 13 previously reported populations were analyzed.Multidimensional scaling and principal component analysis were carried out and phylogenetic trees were also constructed.Results The heterozygosity of 20 STR loci ranged from 0.6009 to 0.9116.Their discrimination power ranged from 0.7745 to 0.9866.The probability of exclusion ranged from 0.2920 to 0.8191 for triplet and from 0.1910 to 0.7086 for biplet.The polymorphism information content ranged from 0.5348 to 0.9093,and no significant deviations from Hardy-Weinberg equilibrium were observed.The total discrimination power was 1-1.3509×10^(-21).The CPEduo was 0.999996523945999,and CPEtrio was 0.999999996129773.Based on the results of multidimensional scaling,principal component analysis and phylogenetic trees of the genetic distances between Hunan Han population and other 13 populations,Hunan Han population was closest to Hubei Han population and was farthest to Yunnan Miao population.Conclusion The 20 autosomal STR loci showed high polymorphism and discriminating ability in Hunan Han population,which can provide a data foundation for personal identification,paternity test and population genetics study in that region.