Forensic characteristic and population structure dissection of Shaanxi Han population in the light of diallelic deletion/insertion polymorphism data

Efficiency evaluation of common forensic genetic markers for parentage identification involving close relatives

To explore the efficacy of commonly used forensic identification panels in complex paternity testing of trios that involved close relatives, we wrote a code by R to generate 10,000 pedigrees at 20 CODIS STR, 21 non-CODIS STR and 30 InDel loci in Chinese five ethnic groups based on their allele frequencies. Parentage identification index--cumulative paternity index (CPI) value was set as output and was further analyzed to evaluate the performance of the aforementioned panels in complex paternity testing when the alleged parent is a random individual, biological parent, grandparent, sibling of biological parent, half-sibling of biological parent, etc. The results showed that the false inclusion of parent sibling posed as parent demonstrated no statistically significant difference from that of grandparent posed as parent. The scenarios where both biological parent and alleged parent were consanguineous to the other parent were also simulated. The results revealed that the complexity of paternity testing would raise when biological parents were consanguineous and the alleged parent was a close relative of theirs. Despite the values of non-conformity number could vary in different genetic relationships, populations and panels, 20 CODIS STRs and 21 non-CODIS STRs performed satisfactorily in most simulated scenarios. However, the joint use of 20 CODIS STRs and 21 non-CODIS STRs is more recommendable when resolving the paternity testing of the incest mating case. Overall, the current study could be regarded as a worthwhile reference in complex paternity testing of trios that involved close relatives.

Twin pregnancy with complete hydatidiform mole and co-existing fetus: A report of 15 cases with a clinicopathological analysis and DNA genotyping

Complete hydatidiform mole (CHM) with co-existing fetus (CHMCF) is very uncommon. In this study, we investigated the clinicopathological features and DNA genotype in 15 CHMCF. Seven patients (46.7%) developed post-molar gestational trophoblastic disease (GTD), 5 of which had lung metastasis. CHMCF was histologically characterized by a mixed pattern of CHM and the non-molar placenta, mimicking partial hydatidiform mole and placental mesenchymal dysplasia. p57 immunostaining showed a divergent staining pattern, positive in the normal placenta and negative in the CHM component. DNA genotyping of the CHM villi demonstrated exclusively paternal alleles consisting of homozygous/monospermic (n = 9) and heterozygous/dispermic patterns (n = 5) at multiple informative loci. We conclude that CHMCF confers a high risk for post-molar GTD. DNA genotyping contributes significantly to the precision diagnosis of CHMCF.

An interpretation of the genetic polymorphism and population genetic background of Ankang Han population via a novel InDel panel

In this research, genotyping data of 43 InDel loci in 311 Han individuals in Ankang City, Shaanxi Province, China were detected using a self-developed five-dye multiplex amplification panel. The allelic frequencies and forensic parameters of all InDel loci were calculated. The combined power of discrimination and probability of exclusion values were 0.999 999 999 999 999 998 827 39 and 0.999 887 424, respectively, which demonstrated that this 43-InDel panel was powerful for individual identifications in Ankang Han population. Moreover, genetic distances, pairwise F_ST values, principal component analyses, phylogenetic trees and STRUCTURE analyses were performed to investigate the genetic affinities between Ankang Han and reference groups. Population genetic investigations indicated that Ankang Han population had a close genetic relationship with Southern Han population compared with other reference groups.

Development a multiplex panel of AISNPs, multi-allelic InDels, microhaplotypes and Y-SNP/InDel loci for multiple forensic purposes via the NGS

Recently, next generation sequencing showed the promising application value in forensic research. In this study, we constructed a multiplex system of different molecular genetic markers based on the previous selected AISNPs, multi-allelic InDels, microhaplotypes and Y-SNP/InDel loci and evaluated forensic efficiencies of the system in Chinese Shaanxi Han, Hui and Mongolian groups via the NGS platform. Ancestry informative analyses of Shaanxi Han, Hui and Mongolian groups revealed that most Mongolian individuals could be differentiated from Shaanxi Hans and Huis based on the selected AISNPs. Multi-allelic InDels and microhaplotypes showed the multiple allele variations and possessed relatively high genetic polymorphisms in these three groups, indicating these loci could also provide higher forensic efficiencies for individual identification and paternity testing. Based on Y-SNPs, different haplogroup distributions were observed among Shaanxi Han, Hui and Mongolian groups. In conclusion, the self-developed system could be used to simultaneously carry out the individual identification, paternity analysis, mixture deconvolution, forensic ancestry information analysis and Y chromosomal haplogroup inference, which could provide more investigative clues in forensic practices. This article is protected by copyright. All rights reserved.