可疑父与孩子生母存在亲缘关系的PI计算  

Calculation of the Paternity Index for the Alleged Father Related to the Child’s Mother

作　　者：王雨婷 朱强 胡渝涵 尉艺凡 侯婷芸 张霁[1] WANG Yu-ting;ZHU Qiang;HU Yu-han;WEI Yi-fan;HOU Ting-yun;ZHANG Ji(West China School of Basic Medical Sciences&Forensic Medicine,Sichuan University,Chengdu 610041,China)

机构地区：[1]四川大学华西基础医学与法医学院,四川成都610041

出　　处：《法医学杂志》2023年第3期271-275,共5页Journal of Forensic Medicine

基　　金：国家自然科学基金资助项目(82072120,82230064)。

摘　　要：目的推导当可疑父与孩子生母具有亲缘关系(亲子、全同胞、爷孙、叔侄、一代表亲)时,可疑父的PI计算公式。方法针对可疑父与孩子生母存在亲缘关系的情况,在PI的分子和分母假设中均考虑亲缘关系的存在,使用考虑母亲基因型的频率公式计算可疑父的基因型频率,同时将分母中的随机男子被替代为母亲的另一个同等级亲属,推导出消除可疑父和孩子生母亲缘关系影响的PI计算公式。结果当可疑父与生母具有一、二、三级亲缘关系时,与不考虑亲缘关系的PI计算方法相比,使用本研究推导出的PI计算公式可以获得更保守的PI。结论本研究提供的计算方法可以消除乱伦案中可疑父与母亲的亲缘关系对PI的影响,从而获得更加准确和保守的鉴定意见。Objective To derive the paternity index(PI)calculation formula of the alleged father(AF)when the AF is a relative(parent/child,siblings,grandparent/grandchild,uncle/nephew,first cousins)of the child’s biological mother.Methods For the case when the AF is related to the child’s biological mother,the existence of the relationship in the numerator and denominator hypothesis of PI was considered.The genotype frequency of the AF was calculated by using the frequency formula in which the mother’s genotype was considered,while the random male in the denominator was substituted as another relative of the mother’s same rank.The PI calculation formula was derived to eliminate the effect of the relationship between AF and the child’s biological mother.Results When the AF and the biological mother have first,second and tertiary kinship,a more conservative PI was obtained from the PI calculation formula derived in this study compared with the PI calculation method which did not consider kinship.Conclusion The calculation method provided in this study can eliminate the effect of the relation of the AF and mother on the PI in incest cases,to obtain more accurate and conservative identification conclusions.

关 键 词：法医遗传学 亲子鉴定 乱伦 亲权指数 似然比 

分 类 号：R89[医药卫生—法医学] DF795.2[医药卫生—临床医学] D919.2[政治法律—诉讼法学]