Chen Anqi, Tao Ruiyang, Li Chengtao, Zhang Suhua
Shanghai Key Laboratory of Forensic Medicine, Shanghai Forensic Service Platform, Academy of Forensic Science, Ministry of Justice, Shanghai, China.
Department of Forensic Medicine, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.
Forensic Sci Res. 2022 Mar 16;7(4):702-707. doi: 10.1080/20961790.2021.2009631. eCollection 2022.
Mutations might challenge the paternity index calculation in forensic identification. While many studies have focussed on the autosomal short tandem repeats (A-STR), the mutation status of sex chromosomes and single nucleotide polymorphism (SNP) remain blank. Next generation sequencing (NGS), known as high throughput and large sequence polymorphism, is a promising tool for forensic genetics. To describe the mutation landscapes in the paternity cases with genetic inconsistencies, a total of 63 parentage confirmed paternity cases contained at least one mismatched locus have been collected. The mutations were subsequently evaluated using Verogen's MPS ForenSeq DNA Signature Kit and a microsatellite instability (MSI) detection kit. The result showed 98.41% (62/63) of the cases had no additional autosomal mutations even when the number of A-STRs increased to 27. As for the sex chromosomes, about 11.11% (7/63) of the cases exhibited either X-STR or Y-STR mutations. D2S1338, FGA and Penta E were the most frequent altered STRs, which suggested they might be the mutation hotspots. In addition, a male with sex chromosome abnormality was observed accidently, whose genotype might be 47, XXY, rather than MSI. Nearly 56.90% of the STR loci possessed isoalleles, which might result in higher STR polymorphisms. No Mendelian incompatibility was detected among the SNP markers, which indicated that SNP was a more reliable genetic marker in the genetic-inconsistent paternity cases. Supplemental data for this article is available online at https://doi.org/10.1080/20961790.2021.2009631 .
突变可能会对法医鉴定中的父权指数计算提出挑战。虽然许多研究都集中在常染色体短串联重复序列（A-STR）上，但性染色体和单核苷酸多态性（SNP）的突变情况仍不清楚。下一代测序（NGS），即高通量和大序列多态性测序，是法医遗传学中一种很有前景的工具。为了描述存在遗传不一致的亲子鉴定案例中的突变情况，共收集了63例经亲子鉴定确认但至少有一个不匹配位点的案例。随后使用Verogen公司的MPS ForenSeq DNA Signature试剂盒和微卫星不稳定性（MSI）检测试剂盒对突变进行评估。结果显示，即使A-STR的数量增加到27个，98.41%（62/63）的案例没有额外的常染色体突变情况发生。至于性染色体，约11.11%（7/63）的案例出现了X-STR或Y-STR突变。D2S1338、FGA和五核苷酸重复序列E（Penta E）是最常发生改变的STR序列，这表明它们可能是突变热点。此外，意外观察到一名性染色体异常的男性，其基因型可能是47, XXY，而非微卫星不稳定性。近56.90%的STR位点存在等位基因，这可能导致更高的STR多态性。在SNP标记中未检测到孟德尔不相容性，这表明在存在遗传不一致的亲子鉴定案例中，SNP是一种更可靠的遗传标记。本文的补充数据可在网上获取，网址为https://doi.org/10.1080/20961790.2021.2009631 。
