法医学杂志 ›› 2023, Vol. 39 ›› Issue (3): 288-295.DOI: 10.12116/j.issn.1004-5619.2023.530101

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

微单倍型在同胞关系鉴定中的应用

唐萱(), 文丹, 王楚东, 许如意, 贾洪涛, 李介男, 扎拉嘎白乙拉()   

  1. 中南大学基础医学院法医学系,湖南 长沙 410013
  • 收稿日期:2023-01-09 发布日期:2023-07-07 出版日期:2023-06-25
  • 通讯作者: 扎拉嘎白乙拉
  • 作者简介:扎拉嘎白乙拉,男,蒙古族,博士,教授,主要从事法医学研究;E-mail:dlkl2001@163.com
    唐萱(1998—),女,博士研究生,主要从事法医学研究;E-mail:962334670@qq.com
  • 基金资助:
    国家自然科学基金重点资助项目(82230064);国家自然科学基金面上资助项目(82271928)

Application of Microhaplotypes in Sibling Kinship Testing

Xuan TANG(), Dan WEN, Chu-dong WANG, Ru-yi XU, Hong-tao JIA, Jie-nan LI, Bai-yi-la ZHALAGA()   

  1. Department of Forensic Medicine, College of Basic Medicine, Central South University, Changsha 410013, China
  • Received:2023-01-09 Online:2023-07-07 Published:2023-06-25
  • Contact: Bai-yi-la ZHALAGA

摘要:

目的 探究不同数量微单倍型(microhaplotype,MH)位点和引入不同参考样本对全同胞、半同胞关系鉴定及区分全和半同胞关系鉴定的效能影响,并探讨改变突变率对于同胞关系鉴定的影响。 方法 首先建立一个涉及三代人的家庭图谱,针对引入的不同参考样本构建4种全同胞关系鉴定模型、5种半同胞关系鉴定模型和5种区分全和半同胞关系模型。基于前期研究结果筛选出分别包含34和54个位点的两组非二等位SNP-MH,基于上述MH位点在相应的同胞关系鉴定模型下,模拟100 000对全同胞-无关个体、100 000对半同胞-无关个体和100 000对全同胞-半同胞,并利用似然比法分析每种同胞关系鉴定模型在不同阈值下的效能,改变54个MH位点的突变率,分析突变率对于同胞关系鉴定的影响。 结果 在同一种关系鉴定模型中,同胞关系鉴定的系统效能与检测的MH位点数量呈正相关。在相同MH位点数量下,引入的参考样本为A的全同胞时,全同胞关系鉴定的效能优于引入A的叔叔或祖父,但对于半同胞关系鉴定和区分全和半同胞关系引入的4种参考样本对于鉴定效能的增加没有显著差异。此外,突变率的高低对同胞关系鉴定效能略有影响。 结论 增加检测MH位点的数量和引入已知亲属参考样本均能够增加全同胞关系鉴定、半同胞关系鉴定、区分全和半同胞关系的效能。以似然比法进行同胞关系鉴定时突变率的高低对效能产生轻微影响,但不显著。

关键词: 法医遗传学, 微单倍型, 同胞关系, 全同胞, 半同胞, 常染色体, 似然比法, 参考样本

Abstract:

Objective To investigate the efficacy of different numbers of microhaplotype (MH) loci and the introduction of different reference samples on the identification of full sibling, half sibling and differentiation between full sibling and half sibling kinships, and to explore the effect of changing mutation rate on sibling testing. Methods First, a family map involving three generations was established, and four full sibling identification models, five half sibling identification models and five models distinguishing full and half siblings were constructed for different reference samples introduced. Based on the results of the previous study, two sets of nonbinary SNP-MH containing 34 and 54 loci were selected. Based on the above MH loci, 100 000 pairs of full sibling vs. unrelated individuals, 100 000 pairs of half sibling vs. unrelated individuals and 100 000 pairs of full sibling vs. half sibling were simulated based on the corresponding sibling kinship testing models, and the efficacy of each sibling kinship testing model was analyzed by the likelihood ratio algorithm under different thresholds. The mutant rate of 54 MH loci was changed to analyze the effect of mutation rate on sibling identification. Results In the same relationship testing model, the systematic efficacy of sibling testing was positively correlated with the number of MH loci detected. With the same number of MH loci, the efficacy of full sibling testing was better than that of uncle or grandfather when the reference sample introduced was a full sibling of A, but there was no significant difference in the identification efficacy of the four reference samples introduced for full sibling and half sibling differentiation testing. In addition, the mutation rate had a slight effect on the efficacy of sibling kinship testing. Conclusion Increasing the number of MH loci and introducing reference samples of known relatives can increase the efficacy of full sibling testing, half sibling testing, and differentiation between full and half sibling kinships. The level of mutation rate in sibling testing by likelihood ratio method has a slight but insignificant effect on the efficacy.

Key words: forensic genetics, microhaplotype, sibling, full sibling, half sibling, autosomes, likelihood ratio method, reference sample

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