Search

Abstract Background In the domain of forensic science, the application of kinship identification and mixture deconvolution techniques are of critical importance, providing robust scientific evidence for the resolution of complex cases. Microhaplotypes, as the emerging class of genetic markers, have been widely studied in forensics due to their high polymorphisms and excellent stability. Results and discussion In this research, a novel and high-efficient panel integrating 33 microhaplotype loci along with a sex-determining locus was developed by the next generation sequencing technology. In addition, we also assessed its forensic utility and delved into its capacity for kinship analysis and mixture deconvolution. The average effective number of alleles (Ae) of the 33 microhaplotype loci in the Guizhou Han population was 6.06, and the Ae values of 30 loci were greater than 5. The cumulative power of discrimination and cumulative power of exclusion values of the novel panel in the Guizhou Han population were 1-5.6 × 10− 43 and 1-1.6 × 10− 15, respectively. In the simulated kinship analysis, the panel could effectively distinguish between parent-child, full-sibling, half-sibling, grandfather-grandson, aunt-nephew and unrelated individuals, but uncertainty rates clearly increased when distinguishing between first cousins and unrelated individuals. For the mixtures, the novel panel had demonstrated excellent performance in estimating the number of contributors of mixtures with 1 to 5 contributors in combination with the machine learning methods. Conclusions In summary, we have developed a small and high-efficient panel for forensic genetics, which could provide novel insights into forensic complex kinships testing and mixture deconvolution.

Abstract Background Even though the Buyei are a recognised ethnic group in southwestern China, there hasn’t been much work done on forensic population genetics, notably using mitochondrial DNA. The sequences and haplogroups of mitochondrial DNA control regions of the Buyei peoples were studied to provide support for the establishment of a reference database for forensic DNA analysis in East Asia. Methods and results The mitochondrial DNA control region sequences of 200 Buyei individuals in Guizhou were investigated. The haplotype frequencies and haplogroup distribution of the Buyei nationality in Guizhou were calculated. At the same time, the paired Fst values of the study population and other populations around the world were computed, to explore their genetic polymorphism and population relationship. A total of 179 haplotypes were detected in the Buyei population, with frequencies of 0.005–0.015. All haplotypes were assigned to 89 different haplogroups. The haplotype diversity and random matching probability were 0.999283 and 0.0063, respectively. The paired Fst genetic distances and correlation p-values among the 54 populations revealed that the Guizhou Buyei was most closely related to the Henan Han and the Guizhou Miao, and closer to the Hazara population in Pakistan and the Chiang Mai population. Conclusions The study of mitochondrial DNA based on the maternal genetic structure of the Buyei nationality in Guizhou will benefit the establishment of an East Asian forensic DNA reference database and provide a reference for anthropological research in the future.