法医学杂志 ›› 2026, Vol. 42 ›› Issue (4): 310-317.DOI: 10.12116/j.issn.1004-5619.2024.540401

• 论著 • 上一篇    下一篇

线粒体DNA遗传变异在四代母系家系中的遗传特征分析

伦妙锖1(), 杨幸怡2, 徐曲毅2, 韩晓龙2, 陈玲1, 王萌鸽3(), 刘超1,4()   

  1. 1.南方医科大学法医学院,广东 广州 510515
    2.广州市刑事科学技术研究所,广东 广州 510080
    3.四川大学华西医院罕见病研究院,四川 成都 610041
    4.广东省毒品实验技术中心,广东 广州 510230
  • 收稿日期:2024-04-03 发布日期:2026-10-28 出版日期:2026-08-25
  • 通讯作者: 王萌鸽,刘超
  • 作者简介:伦妙锖(1999—),女,硕士研究生,主要从事法医物证学研究;E-mail:605104616@qq.com
  • 基金资助:
    法医遗传学公安部重点实验室开放课题资助项目(2020FGKFKT05);广州市科技计划项目(2024B04J0022)

Analysis of Genetic Characteristics of Mitochondrial DNA Genetic Variation in Four⁃Generation Maternal Lineages

Miaoqiang Lun1(), Xingyi Yang2, Quyi Xu2, Xiaolong Han2, Ling Chen1, Mengge Wang3(), Chao Liu1,4()   

  1. 1.School of Forensic Medicine, Southern Medical University, Guangzhou 510515, China
    2.Guangzhou Institute of Criminal Science and Technology, Guangzhou 510080, China
    3.Institute of Rare Diseases, West China Hospital, Sichuan University, Chengdu 610041, China
    4.Anti-drug Technology Center of Guangdong Province, Guangzhou 510230, China
  • Received:2024-04-03 Online:2026-10-28 Published:2026-08-25
  • Contact: Mengge Wang, Chao Liu

摘要:

目的 探究线粒体DNA(mitochondrial DNA,mtDNA)同质性和异质性变异在四代母系家系中的遗传特征。 方法 采集4个四代母系家系23例个体的口腔拭子并提取DNA,构建mtDNA全基因组文库后,应用Ion S5 XL测序系统测序,并进行序列比对和变异分析。 结果 通过对mtDNA全基因组测序数据进行质控和分析,获得的测序覆盖度高达99.73%,平均测序深度为3 458×。23例的mtDNA全基因组序列中,共观察到939个遗传变异,其中883个为点突变,36个为插入缺失变异,20个为异质性变异。同一母系家系个体的mtDNA序列未发现同质性点突变的差异,但存在不同的点异质性(point heteroplasmy,PHP)。 结论 线粒体的PHP变异在遗传过程中可发生变化,将异质性的差异作为排除同一母系来源的指标存在风险。在进行mtDNA序列比对时,如在两个单倍型一致的样本中观察到相同的PHP,且主要等位基因及次要等位基因一致,可作为认定两样本为同一母系来源的增强性证据。

关键词: 法医遗传学, 线粒体DNA, 全基因组测序, 异质性变异, 母系亲缘关系鉴定, 二代测序

Abstract:

Objective To investigate the genetic characteristics of homoplasmic and heteroplasmic mitochondrial DNA (mtDNA) variations in four-generation maternal lineages. Methods Buccal swabs were collected from 23 individuals belonging to 4 four-generation maternal lineages. DNA was extracted, and mtDNA whole genome libraries were constructed. Sequencing was performed using the Ion S5 XL sequencing system, followed by sequence alignment and variation analysis. Results Following quality control and analysis of obtained mtDNA whole genome sequencing data, the sequencing coverage reached 99.73%, and the average sequencing depth was 3 458×. A total of 939 genetic variations were observed, including 883 point mutations, 36 insertion/deletion variations, and 20 heteroplasmic variations. No differentiated homoplasmic point mutations were found in the mtDNA sequences of individuals from the same maternal lineage, whereas inconsistent point heteroplasmies (PHPs) were detected. Conclusion Mitochondrial PHP variations can change during inheritance, and there is a risk of using PHP differences as an exclusion criterion for determining whether individuals come from the same maternal lineage. When comparing mtDNA sequences, if the same PHP is observed in two samples with identical haplotypes and its major and minor alleles are consistent, it can be considered as enhanced evidence to determine that the two samples come from the same maternal lineage.

Key words: forensic genetics, mitochondrial DNA (mtDNA), whole genome sequencing, heteroplasmic variation, matrilineal relationship identification, next-generation sequencing

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