The George Washington University, Department of Forensic Science, 2100 Foxhall Road, NW, Washington, DC, 20007, United States.
The George Washington University, Department of Forensic Science, 2100 Foxhall Road, NW, Washington, DC, 20007, United States.
Forensic Sci Int Genet. 2020 Nov;49:102398. doi: 10.1016/j.fsigen.2020.102398. Epub 2020 Oct 3.
Microhaplotypes (microhaps or MHs) are novel forensically relevant genetic markers that demand large and appropriate allele frequency datasets for their implementation in casework. In this study we report on the allele frequency data of 74 microhap loci (230 SNPs) included in a newly developed 74-plex assay. The panel was tested on the Ion S5 system on a total of 347 samples from four main U.S. population groups of African, European, East Asian and Southwest Hispanic descent. Overall, frequencies of individual alleles at each locus varied considerably among the different population groups. An increase in the average value of gene diversity was also observed as the number of SNPs per locus increased. Most microhap markers showed no significant deviation from Hardy-Weinberg ratios within any of the individual population samples displaying an average power of discrimination between 0.74 and 0.81 and an average probability of exclusion between 0.32 and 0.39. Moreover, the four population groups had no clear genetic affinities with the exception of U.S. European and U.S. Southwest Hispanic populations, which showed the lowest F value. STRUCTURE and principal component analyses (PCA) analysis resulted in effective clustering of the four populations with the U.S. European and Southwest Hispanic showing some overlap. These results support the potential use of this sequence-based 74plex-microhaplotype assay for ancestry inference in addition to previously reported human identification and mixture deconvolution capabilities.
微单倍型（microhaps 或 MHs）是新型的法医学相关遗传标记，在实际应用中需要大量适当的等位基因频率数据。本研究报告了一种新开发的 74 重微单倍型检测试剂盒中 74 个微单倍型（230 个 SNP）的等位基因频率数据。该面板在 Ion S5 系统上对来自四个主要美国人群体（非洲、欧洲、东亚和西南部西班牙裔）的 347 个样本进行了测试。总体而言，不同人群群体中每个微单倍型位点的个体等位基因频率差异很大。随着每个位点 SNP 数量的增加，基因多样性的平均值也有所增加。大多数微单倍型标记在任何个体群体样本中均未偏离 Hardy-Weinberg 比例，平均鉴别力为 0.74 至 0.81，平均排除概率为 0.32 至 0.39。此外，除了美国欧洲和美国西南部西班牙裔人群外，四个人群群体之间没有明显的遗传亲和力，这两个群体的 F 值最低。STRUCTURE 和主成分分析（PCA）分析有效地对四个群体进行了聚类，美国欧洲和西南部西班牙裔人群存在一些重叠。这些结果支持了该基于序列的 74 重微单倍型检测试剂盒除了之前报道的人类身份识别和混合物分解能力外，还可用于推断祖先。
