哈萨克族和土家族人群19个X-STR基因座的遗传学调查及法医学应用

Genetic polymorphism of 19 X-STR loci for forensic application in Kazakh and Tujia population

目的调查19个X-STR基因座在新疆哈萨克族和湖北土家族人群中的遗传多态性,评估其法医学应用价值。方法收集211名新疆哈萨克族和456名湖北土家族无关个体外周血样,提取DNA,采用Microreader TM 19X ID System试剂盒进行聚合酶链式反应(PCR)扩增,采用3500XL遗传分析仪进行电泳分析,GeneMapper ID-X分析等位基因片段大小。统计分析19个X-STR基因座的等位基因频率和群体遗传学参数,对2个民族之间的分布差异进行分析,并与其他地区已有人群数据进行比较。结果经Bonferroni修正,19个X-STR基因座基因型分布在新疆哈萨克族和湖北土家族群体中符合Hardy-Weinberg平衡定律;基因座之间不存在连锁不平衡现象。这19个X-STR基因座在女性群体的累积个人识别率均大于0.99999999999,在男性群体的累积个人识别率均大于0.99999999994,在三联体中的累积非父排除率均大于0.99999999931,在二联体中的累积非父排除率均大于0.99999950。通过Arlequin v3.5软件计算P值,不同人群间X-STR基因座的频率分布差异有统计学意义(P<0.05)。结论19个X-STR基因座在新疆哈萨克族和湖北土家族人群中具有较高的多态性,能达到较高的个体识别能力,可以作为现有STR检验体系的补充。

Objective To investigate the genetic data of the 19 X-STR loci in Xinjiang Kazakh and Hubei Tujia population,and to assess the application value in forensic science.Methods The DNA samples of unrelated individual in 211 unrelated Xinjiang Kazakh and 456 unrelated Hubei Tujia population were amplified using Microreader TM 19X ID System kit,and the polymerase chain reaction(PCR)products were analyzed by electrophoresis through 3500XL genetic analyzer.The fragment sizes of alleles were taken subsequently by GeneMapper ID-X.Allele frequencies and population genetics parameters of the 19 X-STR were analyzed by statistics.The allele frequencies were compared among the two nationalities and were compared with available data of other populations from different regions.Results After the Bonferroni correction,no significant departures from the Hardy-Weinberg equilibrium were observed.Linkage disequilibrium test showed no significant allelic association between all 19 X-STR loci after Bonferroni′s correction.The cumulative discrimination power in females and in males were greater than 0.99999999999 and 0.99999999994 respectively.The combined power of exclusion in trios and in duos were greater than 0.99999999931 and 0.99999950 respectively.The P values,calculated through Arlequin v3.5 software,there were statistically significant differences detected at loci of X-STR among the different nationalities(P<0.05).Conclusion These 19 X-STR are highly polymorphic in Xinjiang Kazakh and Hubei Tujia population,which can be served as a supplementary to the current STR system for individual identification.