两种计数法预测叔侄关系的对比研究

目的对比等位基因全不同基因座及共有等位基因计数法预测叔侄关系的差异性、相似性及其效能,为侦破案件提供参考。方法以已知叔侄关系的204对作为实验组,无关个体的204对作为对照组,采用PowerPlex 21系统检测20个常染色体STR基因座,然后进行统计分析。结果设定等位基因全不同基因座数预测界值≤6个,发现叔侄关系的灵敏度为83.82%,特异性为74.02%,漏判率为8.82%,误判率为11.76%,系统效能为78.92%。共有等位基因数预测界值≥17个,发现叔侄关系的灵敏度为75.98%,特异性为77.45%,漏判率与误判率均为7.84%,系统效能为76.72%。结论等位基因全不同基因座计数法与共有等位基因数计数法有互补优势,联合应用能提高预测叔侄血亲关系的能力,对侦查具有良好的指导意义。

A comparative study of two counting methods for predictiing uncle-nephew relationship investigation cases

Objective To compared the all-different loci counting method and the number of shared alleles counting method to predict Nephew-uncle Relations by the differences,similarities and efficiency of the two methods,and provide a reference for the detection of cases.Methods 204 pairs of uncle-nephews were used as experimental group,204 pairs of unrelated individuals as control group.Autosomal STR was detected and 20 autosomal loci of PowerPlex 21 system were used for statistical analysis.Results The predicted boundary value of all-different loci was≤6,and the sensitivity was 83.82%,the specificity was 74.02%,the missed rate was 8.82%,the false positive rate was 11.76%,and the system efficiency was 78.92%.The predicted boundary value of the shared alleles was≥17,and the sensitivity was 75.98%,the specificity was 77.45%,the rate of missed and false positives was both 7.84%,and the system efficiency was 76.72%.Conclusion The all-different loci counting method and the shared alleles number counting method have complementary advantages,and combined application can improve the ability to predict nephewuncle relationship,and has good guiding significance for investigation.