Yang Qinrui, Qian Jinglei, Shao Chengchen, Yao Yining, Zhou Zhihan, Xu Hongmei, Tang Qiqun, Qian Xiaoqin, Xie Jianhui
Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai, China.
Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China.
Front Genet. 2021 Nov 17;12:784605. doi: 10.3389/fgene.2021.784605. eCollection 2021.
The application of X-chromosomal short tandem repeats (X-STRs) has been recognized as a powerful tool in complex kinship testing. To support further development of X-STR analysis in forensic use, we identified nine novel X-STRs, which could be clustered into three linkage groups on Xp21.1, Xq21.31, and Xq23. A multiplex PCR system was built based on the electrophoresis. A total of 198 unrelated Shanghai Han samples along with 168 samples from 43 families was collected to investigate the genetic polymorphism and forensic parameters of the nine loci. Allele numbers ranged from 5 to 12, and amplicon sizes ranged from 146 to 477 bp. The multiplex showed high values for the combined power of discrimination (0.99997977 in males and 0.99999999 in females) and combined mean exclusion chances (0.99997918 and 0.99997821 in trios, 0.99984939 in duos, and 0.99984200 in deficiency cases). The linkage between all pairs of loci was estimated via Kosambi mapping function and linkage disequilibrium test, and further investigated through the family study. The data from 43 families strongly demonstrated an independent transmission between LGs and a tight linkage among loci within the same LG. All these results support that the newly described X-STRs and the multiplex system are highly promising for further forensic use.
X染色体短串联重复序列（X-STRs）的应用已被公认为是复杂亲缘关系鉴定中的一项强大工具。为支持X-STR分析在法医领域的进一步发展，我们鉴定出9个新型X-STRs，它们可聚类为位于Xp21.1、Xq21.31和Xq23上的三个连锁群。基于电泳构建了一个多重PCR系统。共收集了198份上海汉族无关个体样本以及来自43个家庭的168份样本，以研究这9个位点的遗传多态性和法医参数。等位基因数范围为5至12，扩增子大小范围为146至477 bp。该多重体系在男性中的联合鉴别力（0.99997977）和女性中的联合鉴别力（0.99999999）以及联合平均排除机会（三人组中为0.99997918和0.99997821，二人组中为0.99984939，缺失样本中为0.99984200）方面显示出较高值。通过Kosambi作图函数和连锁不平衡检验估计所有位点对之间的连锁关系，并通过家系研究进一步调查。来自43个家庭的数据有力地证明了连锁群之间的独立传递以及同一连锁群内位点之间的紧密连锁。所有这些结果均支持新描述的X-STRs和多重体系在法医领域的进一步应用中具有很高的前景。
