随机模拟法进行单亲累积亲权指数分析

目的以随机模拟法进行大量单亲累积亲权指数(CPI)统计分析。方法针对Identifiler、PP18D、PP21、AGCU EX20、AGCU 21+1等5个试剂盒,使用自主研发软件,随机模拟100万组单亲组合并计算单亲PI,统计各试剂盒单亲极低CPI比率(R_(VLCPI))、各基因座的PI中位数(M_(PI))和39个基因座的平均单基因座单亲PI(PI_(solo)),并推导增加检测的基因座个数(N)的计算公式。结果 Identifiler、PP18D、AGCU EX20、PP21、AGCU EX20AGCU 21+1的R_(VLCPI)分别为24.9%、6.5%、1.4%、0.7%、0.000 1%。在各试剂盒的基因座存在包含关系的前提下,R_(VLCPI)和常染色体基因座数成负相关。PI_(solo)为1.843 2。M_(PI)与PE_(duo)呈显著的正相关(r=0.956,P0.001)。增加检测的基因座个数公式为N=「log_(1.843 2)(10 000/P)■。结论本文结果和公式对单亲鉴定案具有一定的应用价值。

Research cumulative paternity index in single-parentage identiifcation with stochastic simulation method

Objective To analyze a large number of Cumulative Paternity Index (CPI) data in Single-parentage identification with stochastic simulation method. Methods Using the software in Identifiler, PP18D, AGCU EX20, PP21, AGCU 21+1 system, 1 million groups of STR genotyping of parent-child were analyzed. The average rate of very low CPI (RVLCPI), the median of PI in every loci (MPI), and the average PI of 39 STR loci (PIsolo) were counted out. And calculation formula of the number of STR loci that need more testing (N) was derived. Results RVLCPI in Identiifler, PP18D, AGCU EX20, PP21, AGCU 21+1 system were 24.9%, 6.5%, 1.4%, 0.7%, 0.000 1%. On the premise of inclusion relations between every kits, the number of autosome STR loci is inversely proportional to RVLCPI. PIsolo was 1.843 2. There was a signiifcant positive correlation between MPI and PEduo (r=0.956, P<0.001). The formula of the number of STR loci that need more testing was N=?log1.843 2(10 000/P)?. Conclusion The result and the formula in this paper are effcient in single-parentage identiifcation.