Tillmar Andreas O, Phillips Chris
Department of Forensic Genetics and Forensic Toxicology, National Board of Forensic Medicine, Linköping, Sweden; Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
Forensic Genetics Unit, Institute of Legal Medicine, University of Santiago de Compostela, Santiago de Compostela, Spain.
Forensic Sci Int Genet. 2017 Jan;26:58-65. doi: 10.1016/j.fsigen.2016.10.007. Epub 2016 Oct 15.
Advances in massively parallel sequencing technology have enabled the combination of a much-expanded number of DNA markers (notably STRs and SNPs in one or combined multiplexes), with the aim of increasing the weight of evidence in forensic casework. However, when data from multiple loci on the same chromosome are used, genetic linkage can affect the final likelihood calculation. In order to study the effect of linkage for different sets of markers we developed the biostatistical tool ILIR, (Impact of Linkage on forensic markers for Identity and Relationship tests). The ILIR tool can be used to study the overall impact of genetic linkage for an arbitrary set of markers used in forensic testing. Application of ILIR can be useful during marker selection and design of new marker panels, as well as being highly relevant for existing marker sets as a way to properly evaluate the effects of linkage on a case-by-case basis. ILIR, implemented via the open source platform R, includes variation and genomic position reference data for over 40 STRs and 140 SNPs, combined with the ability to include additional forensic markers of interest. The use of the software is demonstrated with examples from several different established marker sets (such as the expanded CODIS core loci) including a review of the interpretation of linked genetic data.
大规模平行测序技术的进步使得大量扩充的DNA标记（特别是单个或组合多重体系中的短串联重复序列和单核苷酸多态性）得以结合，目的是增加法医案件工作中的证据权重。然而，当使用来自同一条染色体上多个位点的数据时，基因连锁会影响最终的似然性计算。为了研究不同标记集的连锁效应，我们开发了生物统计学工具ILIR（基因连锁对身份和亲属关系测试法医标记的影响）。ILIR工具可用于研究基因连锁对法医检测中任意一组标记的总体影响。ILIR的应用在标记选择和新标记面板设计过程中可能有用，对于现有标记集来说，作为一种逐案正确评估连锁效应的方法也高度相关。ILIR通过开源平台R实现，包括40多个短串联重复序列和140个单核苷酸多态性的变异和基因组位置参考数据，并具备纳入其他感兴趣的法医标记的能力。通过几个不同的既定标记集（如扩充的联合DNA索引系统核心位点）的示例展示了该软件的使用，包括对连锁遗传数据解释的综述。
