Massively parallel sequencing of 74 microhaplotypes and forensic characteristics in three Chinese Sino-Tibetan populations

Microhaplotype (MH), as an emerging type of forensic genetic marker in recent years, has the potential to support multiple forensic applications, especially for mixture deconvolution and biogeographic ancestry infer-ence. Herein, we investigated the genotype data of 74 MHs included in a novel MH panel, the Ion AmpliSeq MH-74 Plex Microhaplotype Research Panel, in three Chinese Sino-Tibetan populations (Han, Tibetan, and Yi) using the Ion Torrent semiconductor sequencing. The sequencing performance, allele frequencies, effective number of alleles (A), informativeness (I-n), and forensic parameters were subsequently estimated and calculated. In addition, principal component analysis (PCA) and structure analysis were performed to explore the population relationships among the three populations and the ancestry component distribution. Overall, this novel MH panel is robust and reliable, and has an excellent sequencing performance. The Ae values ranged from 1.0126 to 7.0855 across all samples, and 75.68 % of MHs had A(e) values >2.0000. Allele frequencies at some loci varied consid-erably among the three studied populations, and the mean In value was 0.0195. Moreover, the genetic affinity between Tibetans and Yis was closer than that between Tibetans and Hans. The aforementioned results suggest that the Ion AmpliSeq MH-74 Plex Microhaplotype Research Panel is highly polymorphic in three investigated populations and could be used as an effective tool for human forensics. Although these 74 MHs have demon-strated the competency in continental population stratification, a higher resolution for distinguishing intra-continental subpopulations and a more comprehensive database with sufficient reference population data still remain to be accomplished.

Automated summary

In this study, the genotype data of 74 microhaplotypes (MHs) in three Chinese populations were analyzed using Ion Torrent semiconductor sequencing. Results showed that the Ion AmpliSeq MH-74 Plex Microhaplotype Research Panel is highly polymorphic and can be used as an effective tool for human forensics.