Department of Forensic Genetics, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu 610041, Sichuan, China.
Department of Immunology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu 610041, Sichuan, China.
Forensic Sci Int Genet. 2019 Mar;39:1-7. doi: 10.1016/j.fsigen.2018.11.005. Epub 2018 Nov 16.
Microhaplotype markers are emerging forensic genetic markers that have received broad attention in forensics and may supplement existing genetic marker panels. Short tandem repeat polymorphisms (STRPs) and single nucleotide polymorphisms (SNPs) are the general genetic markers at present. Stutter and the high mutation rate of STR markers and the low polymorphism of SNP markers obstruct the solving of certain cases. Kidd proposed microhaplotype markers that encompass 2-4 SNPs. In this study, we screened microhaplotype loci through three criteria, and chose the Illumina MiSeq platform to sequence the new markers. A new nomenclature was proposed and Perl-based tool FLfinder was designed to genotype the microhaplotype marker. After counting the number of haplotypes in samples that were sequenced and calculating common forensic parameters, 13 loci with high polymorphism were reported. Twelve of the 13 loci had an average allele coverage ratio (ACR) of 0.72 to 0.92. Structure analysis showed that 2504 samples (1000 genome project) could be divided into 5 groupings of populations, and each one representing a continental origin. The finding indicates that microhaplotype markers could be used for individual identification and ancestry inference, and a new choice is provided for forensic practice in the future.
微单倍型标记是新兴的法医遗传学标记，在法医学中受到广泛关注，可能补充现有的遗传标记面板。短串联重复多态性（STRPs）和单核苷酸多态性（SNPs）是目前常见的遗传标记。等位基因扩增和 STR 标记的高突变率以及 SNP 标记的低多态性阻碍了某些案件的解决。Kidd 提出了包含 2-4 个 SNPs 的微单倍型标记。在这项研究中，我们通过三个标准筛选微单倍型基因座，并选择 Illumina MiSeq 平台对新标记进行测序。提出了新的命名法，并设计了基于 Perl 的工具 FLfinder 来对微单倍型标记进行基因分型。在对测序样本进行单倍型数量计数并计算常见法医参数后，报告了 13 个具有高多态性的基因座。这 13 个基因座中有 12 个的平均等位基因覆盖率（ACR）为 0.72 到 0.92。结构分析表明，2504 个样本（1000 基因组计划）可以分为 5 个种群分组，每个分组代表一个大陆起源。这一发现表明，微单倍型标记可用于个体识别和祖籍推断，为未来的法医实践提供了新的选择。
