父系母系均突变的双亲鉴定亲权指数计算方法  

Calculation method of paternity index in parentage testing of both paternal and maternal mutations

作　　者：吴世超 周密 Wu Shichao;Zhou Mi(Anhui Vocational College of Police Officers,Anhui,HeFei 230031,China;Wiuhu Public Security Bureau,Anhui,Wuhu 241000,China)

机构地区：[1]安徽警官职业学院,安徽合肥230031 [2]芜湖市公安局,安徽芜湖241000

出　　处：《中国法医学杂志》2024年第4期395-398,共4页Chinese Journal of Forensic Medicine

基　　金：安徽警官职业学院校级自然科学研究重点项目(2022zkxm001)。

摘　　要：目的 探讨父系母系均突变情况下的双亲鉴定亲权指数(PI)的计算方法。方法 本研究首先根据孟德尔遗传定律和突变基础模型,推导双亲鉴定的PI通用公式;其次在通用公式基础上,从子-母-父表型上分析,将父系母系均突变情况归纳为8类,推导该情况下的亲母疑父PI(PI_(AF))和双亲皆疑PI(PI_(AP))的分项公式;最后设计模拟实验在EX20试剂盒的19个常染色体基因座上生成10 000个由无关个体组成的父母子,统计符合遗传规律组(c组)、父系或母系单方突变组(s组)和父系母系均突变组(d组)的百分比,分别计算亲母疑父组和双亲皆疑组的PI最小值(min)、最大值(max)和平均数(x),同时计算亲母疑父组和双亲皆疑组的累积亲权指数(CPI)的min、max和几何平均数(Π)。结果 本研究推导出父系母系均突变情况下的全部双亲鉴定PI公式。c组、s组和d组PI的min、max和x有“min_(c)>min_(s)>min_(d),max_(c)>max_(s)>max_(d),x_(c)>x_(s)>x_(d)”的规律。所有模拟案例的CPI均满足排除亲缘关系的条件。结论 本文公式可应用于父系母系均突变情况下的双亲鉴定PI计算。Objective To explore a method of calculating the paternity index(PI)in parentage testing of both paternal and maternal mutations.Methods In this study,the general formulas of PI in parentage testing were derived based on Mendel's laws of inheritance and mutation basic model first.Subsequently,on the basis of the general formula,parentage testing of both paternal and maternal mutations were classified into 8 types according to child-mother-father genotypes.From,these classifications,detailed formulas of PI in alleged father cases(PIAF)and PI in alleged parent cases(PIAP)were further refined.Finally,a simulation experiment was designed to generate 10,000 parents composed of unrelated individuals on 19 autosomal loci of the EX20 kit,and the percentages of mutations of confirming group(c group),single mutant group(s group),and double mutants group(d group)were calculated.the min,max,and arithmetic mean(x)of PI in alleged father groups and alleged parent groups were all calculated based on simulated data.Meanwhile,the min,max,and geometric mean(Π)of cumulative parentageindex(CPI)were calculated in the same two groups.Results In this study,All PI formulas of both paternal and maternal mutations in parentage testing were derived.The conclusive analysis of the min,max and mean(x)of PI in group c,group s,and group d led out the following rules:min_(c)>min_(s)>min_(d),max_(c)>max_(s)>max_(d),x_(c)>x_(s)>x_(d).The CPI of all simulation cases met the conditions of excluding kinship.Conclusion The PI formulas in this paper could be applied to parentage testing of both paternal and maternal mutations.

关 键 词：法医遗传学 常染色体STR 亲权指数 突变 

分 类 号：D919.2[医药卫生—法医学]