Kling Daniel, Tillmar Andreas O, Egeland Thore
Department of Family Genetics, Norwegian Institute of Public Health, Oslo, Norway; Department for Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Aas, Norway.
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 Sci Int Genet. 2014 Nov;13:121-7. doi: 10.1016/j.fsigen.2014.07.004. Epub 2014 Jul 10.
In relationship testing the aim is to determine the most probable pedigree structure given genetic marker data for a set of persons. Disaster Victim Identification (DVI) based on DNA data from presumed relatives of the missing persons can be considered to be a collection of relationship problems. Forensic calculations in investigative mode address questions like "How many markers and reference persons are needed?" Such questions can be answered by simulations. Mutations, deviations from Hardy-Weinberg Equilibrium (or more generally, accounting for population substructure) and silent alleles cannot be ignored when evaluating forensic evidence in case work. With the advent of new markers, so called microvariants have become more common. Previous mutation models are no longer appropriate and a new model is proposed. This paper describes methods designed to deal with DVI problems and a new simulation model to study distribution of likelihoods. There are softwares available, addressing similar problems. However, for some problems including DVI, we are not aware of freely available validated software. The Familias software has long been widely used by forensic laboratories worldwide to compute likelihoods in relationship scenarios, though previous versions have lacked desired functionality, such as the above mentioned. The extensions as well as some other novel features have been implemented in the new version, freely available at www.familias.no. The implementation and validation are briefly mentioned leaving complete details to Supplementary sections.
在亲缘关系鉴定中,目标是根据一组人员的遗传标记数据确定最可能的谱系结构。基于失踪人员假定亲属的DNA数据进行灾难受害者身份识别(DVI)可被视为一系列亲缘关系问题。调查模式下的法医计算会涉及诸如“需要多少个标记和参考人员?”等问题。此类问题可通过模拟来回答。在实际案件工作中评估法医证据时,突变、偏离哈迪 - 温伯格平衡(或更一般地说,考虑群体亚结构)以及沉默等位基因不能被忽视。随着新标记的出现,所谓的微变体变得更加常见。以前的突变模型不再适用,因此提出了一种新模型。本文描述了旨在处理DVI问题的方法以及一种用于研究似然分布的新模拟模型。有一些软件可用于解决类似问题。然而,对于包括DVI在内的一些问题,我们不知道有免费可用的经过验证的软件。Familias软件长期以来在全球法医实验室中被广泛用于计算亲缘关系场景中的似然性,不过以前的版本缺乏所需的功能,如上述功能。新版本中实现了扩展以及一些其他新功能,可在www.familias.no免费获取。本文简要提及了其实现和验证过程,完整细节留至补充部分。