法医学杂志 ›› 2023, Vol. 39 ›› Issue (3): 262-270.DOI: 10.12116/j.issn.1004-5619.2023.530107

所属专题: 法医学亲子和亲缘关系鉴定专题

• 论著 • 上一篇    下一篇

生物学半同胞关系鉴定策略

谭政(), 马冠车, 付丽红, 张晓静, 王茜, 付光平, 杜情情, 李淑瑾()   

  1. 河北医科大学法医学院 河北省法医学重点实验室,河北 石家庄 050017
  • 收稿日期:2023-01-25 发布日期:2023-07-29 出版日期:2023-06-25
  • 通讯作者: 李淑瑾
  • 作者简介:李淑瑾,女,博士,教授,博士研究生导师,主要从事法医遗传学研究;E-mail:shujinli@163.com
    谭政(1995—),男,土家族,硕士,主要从事法医遗传学研究;E-mail:1181721388@qq.com
  • 基金资助:
    国家自然科学基金资助项目(82072118);河北省自然科学基金资助项目(H2021206451);河北省省级科技计划资助项目(225A5602D)

Identification Strategy of Biological Half Sibling Relationship

Zheng TAN(), Guan-ju MA, Li-hong FU, Xiao-jing ZHANG, Qian WANG, Guang-ping FU, Qing-qing DU, Shu-jin LI()   

  1. Hebei Key Laboratory of Forensic Medicine, College of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China
  • Received:2023-01-25 Online:2023-07-29 Published:2023-06-25
  • Contact: Shu-jin LI

摘要:

目的 比较似然比(likelihood ratio,LR)法和状态一致性(identity by state,IBS)法在半同胞关系鉴定中的应用价值,为制定半同胞鉴定相关规范提供参考。 方法 (1)基于相同的遗传标记组合,比较实际案例与计算机模拟案例的累计状态一致性评分(cumulated identity by state score,CIBS)与累积全同胞关系指数分布,验证计算机模拟方法的可信度;(2)模拟获得全同胞、半同胞、无关个体对各100万对在不同数量的三种类型遗传标记上的分型,分别计算CIBS和相应类型的累积LR参数;(3)比较基于不同数据、不同种类的遗传标记、应用不同准确度标准区分上述三种关系个体对时,LR法和IBS法所能提供的最佳系统效能,以比较两种方法在上述鉴定中的应用价值;(4)根据已有模拟数据,以曲线拟合的方式估计应用不同类型遗传标记鉴别半同胞与另两种关系个体对所需的最低遗传标记数目。 结果 (1)经秩和检验,在真实关系和检验的遗传标记组合相同的前提下,模拟方法与实际案例所得结果差异无统计学意义;(2)多数情况下,在其他条件设置相同时,LR法的系统效能大于IBS法;(3)基于现有数据,可以通过曲线拟合的方式得到全-半同胞鉴定和半同胞鉴定在系统效能达到0.95或0.99时所需遗传标记的数目。 结论 在进行甄别全同胞对和半同胞对或甄别半同胞对和无关个体对的鉴定时,推荐优先使用LR法,并根据拟进行的鉴定类型和基于的人群数据估计所需遗传标记数目,以保证鉴定效果。

关键词: 法医遗传学, 同胞关系, 半同胞, 似然比, 状态一致性, 短串联重复序列, 单核苷酸多态性, 微单倍型

Abstract:

Objective To compare the application value of the likelihood ratio (LR) method and identity by state (IBS) method in the identification involving half sibling relationships, and to provide a reference for the setting of relevant standards for identification of half sibling relationship. Methods (1) Based on the same genetic marker combinations, the reliability of computer simulation method was verified by comparing the distributions of cumulated identity by state score (CIBS) and combined full sibling index in actual cases with the distributions in simulated cases. (2) In different numbers of three genetic marker combinations, the simulation of full sibling, half sibling and unrelated individual pairs, each 1 million pairs, was obtained; the CIBS, as well as the corresponding types of cumulative LR parameters, were calculated. (3) The application value of LR method was compared with that of IBS method, by comparing the best system efficiency provided by LR method and IBS method when genetic markers in different amounts and of different types and accuracy were applied to distinguish the above three relational individual pairs. (4) According to the existing simulation data, the minimum number of genetic markers required to distinguish half siblings from the other two relationships using different types of genetic markers was estimated by curve fitting. Results (1) After the rank sum test, under the premise that the real relationship and the genetic marker combination tested were the same, there was no significant difference between the simulation method and the results obtained in the actual case. (2) In most cases, under the same conditions, the system effectiveness obtained by LR method was greater than that by IBS method. (3) According to the existing data, the number of genetic markers required for full-half siblings and half sibling identification could be obtained by curve fitting when the system effectiveness reached 0.95 or 0.99. Conclusion When distinguishing half sibling from full sibling pairs or unrelated pairs, it is recommended to give preference to the LR method, and estimate the required number of markers according to the identification types and the population data, to ensure the identification effect.

Key words: forensic genetics, sibling relationship, half sibling, likelihood ratio, identity by state, short tandem repeats, single nucleotide polymorphism, microhaplotype

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