SiFaSTR^(TM) 23plex DNA身份鉴定系统在华东汉族人群中的法医学应用

Forensic Application of SiFaSTR^(TM) 23plex DNA ID System in Han Population of Eastern China

目的调查SiFaSTR^(TM)23plexDNA身份鉴定系统所包含的21个常染色体STR基因座及DYS391基因座在华东地区汉族人群中的遗传多态性,并评估其在法医学中的应用价值。方法采用SiFaSTR^(TM)23plexDNA身份鉴定系统对2000名无关个体进行分型检测,统计分析上述STR基因座的群体遗传学参数。采用该试剂盒对支持亲子关系的3198例案例进行检测,观察21个常染色体STR基因座的突变情况。结果21个常染色体STR基因座均符合Hardy-Weinberg平衡(P>0.05),Ho为0.6175~0.9270,DP为0.7964~0.9869,PIC为0.5611~0.9123,CDP为0.999999999999999,CPE_(duo)为0.999997431701961,CPE_(trio)为0.999999999654865。DYS391基因座共检出5个等位基因,等位基因频率在0.0040~0.7290,GD为0.4189。除D13S317和D10S1248外,其余19个常染色体STR基因座共观察到76次突变,其中一步突变75次(98.68%),三步突变1次(1.32%),突变率为0.2465×10^(-3)~2.7114×10^(-3),21个常染色体STR基因座平均突变率为0.8921×10^(-3)(95%置信区间为0.70×10^(-3)~1.10×10^(-3))。33例三联体突变事件中,父、母源性突变比例为2.09∶1。结论SiFaSTR^(TM)23plexDNA身份鉴定系统在华东地区汉族人群中具有良好的遗传多态性,且各STR基因座突变率在可接受范围内,可用于法医学亲权鉴定和个体识别。

Objective To investigate the genetic polymorphism of 21 autosomal STR loci and DYS391 locus of Si Fa STR^TM 23 plex DNA ID system in Han population of eastern China and to evaluate its application value in forensic science. Methods Typing test of 2 000 unrelated individuals was performed using Si Fa STR^TM23 plex DNA ID system. The population genetic parameters of STR loci were statistically analysed. A total of 3 198 parentage confirmed cases were detected with that system and the mutation conditions were observed in 21 autosomal STR loci. Results All the 21 autosomal STR loci showed no significant departure from Hardy-Weinberg equilibrium（P〉0.05）. The Ho ranged from 0.617 5 to 0.927 0.The DP ranged from 0.796 4 to 0.986 9, as well as the PIC distributed from 0.561 1 to 0.912 3. The CDP was 0.999 999 999 999 999. The CPEduo was 0.999 997 431 701 961, while CPEtriowas 0.999 999 999 654 865.Five alleles were detected in DYS391 locus, with the allele frequency from 0.004 0 to 0.729 0, and GD was 0.418 9. Except D13 S317 and D10 S1248, seventy-six mutation events were observed at the rest nineteen autosomal STR loci. Among them, seventy-five（98.68%） were one step mutation, and only one（1.32%） was three steps mutation. The mutation rate ranged from 0.246 5×10^-3 to 2.711 4×10^-3, and the averaged mutation rate was 0.892 1×10^-3（95% CI： 0.70×10^-3-1.10×10^-3）. In 33 trio mutation cases, the proportion of the paternal mutation and the maternal mutation was 2.09 ∶1. Conclusion The involved STRs are highly polymorphic in Eastern Han population with acceptable mutation rates by the Si Fa STR^TM23 plex DNA ID system, which is suitable for paternity testing and individual identification.