Two-person DNA mixture interpretation based on a novel set of SNP-STR markers

Publication date: Available online 26 July 2018Source: Forensic Science International: GeneticsAuthor(s): Yu Tan, Peng Bai, Li Wang, Hui Wang, Huan Tian, Hui Jian, Ranran Zhang, Yuqing Liu, Weibo Liang, Lin ZhangAbstractAutosomal short tandem repeats (STR) markers analysed by PCR and capillary electrophoresis (CE) represent the gold-standard for forensic DNA analysis. With the improved sensitivity of detection equipment, a larger number of mixed DNA profiles can be obtained from trace amounts of DNA that conventionally used to appear as a single source. More specifically, two-source DNA mixtures, comprising the victim’s and the perpetrator’s DNAs, are often encountered in forensic casework, where the victim’s DNA represents a major component of the mixture. Unfortunately, unbalanced two-person DNA mixtures with a ratio larger than 20:1 (here we have named this kind of mixture extremely unbalanced DNA mixture) provide limited information on the minor component. Although the development of probabilistic software has made interpretation of results from mixed DNA easier, high mixture ratios lead to an uninformative likelihood ratio (LR), considering the minor component. Therefore, a technique that can be performed on the conventional CE platform, while enhancing the ability to detect minor DNA in extremely unbalanced DNA mixtures, may be very useful in forensic casework. Our previous research has reported that SNP-STRs, in conjunction with a PCR technique based on amplifica...
Source: Forensic Science International: Genetics - Category: Forensic Medicine Source Type: research