DNA commission of the International Society of Forensic Genetics: Recommendations on the evaluation of STR typing results that may include drop-out and/or drop-in using probabilistic methods.
DNA commission of the International Society of Forensic Genetics: Recommendations on the evaluation of STR typing results that may include drop-out and/or drop-in using probabilistic methods.
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DOI：
10.1016/j.fsigen.2012.06.002
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发表时间：
2012-12
期刊：
影响因子：
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通讯作者：
Weir BS
中科院分区：
文献类型：
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作者：
Gill P;Gusmão L;Haned H;Mayr WR;Morling N;Parson W;Prieto L;Prinz M;Schneider H;Schneider PM;Weir BS
对犯罪现场的生物材料进行DNA分析往往很复杂，因为DNA的数量有限，而且DNA的质量可能会受到影响。此外，STR分型试剂盒的灵敏度不断提高，以检测低水平的DNA痕迹。这可能导致（1）部分DNA图谱和（2）检测到额外的等位基因。有两个关键现象需要考虑：等位基因或基因座“脱落”，即在一个或多个遗传基因座上“缺失”等位基因，而“脱落”可以解释DNA谱中除了假定的主要贡献者之外的等位基因。落入现象被限制为每个谱1或2个等位基因。如果在两个以上的基因座处观察到多个等位基因，则这些等位基因被认为是来自额外贡献者的等位基因，并且分析可以作为两个或更多个贡献者的混合物进行。在这里，我们给出了关于如何估计考虑脱落Pr（D）和脱落Pr（C）的概率的建议。为了清楚起见，我们特意限制了目前的建议，只考虑一个地点的辍学和/或辍学。此外，我们提供了建议，如何使用Pr（D）和Pr（C）的似然比的原则，通常推荐的国际社会法医遗传学（ISFG）作为衡量的证据在法医遗传学的权重。计算的例子包括在内。提供了Excel电子表格，以便科学家和实验室可以探索模型并输入自己的数据。
DNA profiling of biological material from scenes of crimes is often complicated because the amount of DNA is limited and the quality of the DNA may be compromised. Furthermore, the sensitivity of STR typing kits has been continuously improved to detect low level DNA traces. This may lead to (1) partial DNA profiles and (2) detection of additional alleles. There are two key phenomena to consider: allelic or locus ‘drop-out’, i.e. ‘missing’ alleles at one or more genetic loci, while ‘drop-in’ may explain alleles in the DNA profile that are additional to the assumed main contributor(s). The drop-in phenomenon is restricted to 1 or 2 alleles per profile. If multiple alleles are observed at more than two loci then these are considered as alleles from an extra contributor and analysis can proceed as a mixture of two or more contributors. Here, we give recommendations on how to estimate probabilities considering drop-out, Pr(D), and drop-in, Pr(C). For reasons of clarity, we have deliberately restricted the current recommendations considering drop-out and/or drop-in at only one locus. Furthermore, we offer recommendations on how to use Pr(D) and Pr(C) with the likelihood ratio principles that are generally recommended by the International Society of Forensic Genetics (ISFG) as measure of the weight of the evidence in forensic genetics. Examples of calculations are included. An Excel spreadsheet is provided so that scientists and laboratories may explore the models and input their own data.