Genetic diversity of 23 STR loci of the Guizhou Tujia ethnic minority and the phylogenetic relationships with 22 other populations

Background: Short tandem repeats (STR) are highly polymorphic DNA markers utilised in forensic personal identification and human population genetic research. Guizhou Tujia is one of the ancient minority groups in southwest China, however, the population has not been studied using the highly discriminating 23 STR Huaxia Platinum Kit. Aim: To obtain genetic data from 23 autosomal STRs in Guizhou Tujia and examine the population's relationship with others. Subjects and methods: A total of 480 individuals from the Guizhou Tujia population were analysed using 23 STR loci of Huaxia Platinum Kit. Allele frequencies and forensic parameters were estimated. Population genetic relationships were calculated by Nei's genetic distances and visualised using a variety of biostatistical methods. Results A total of 264 alleles were found, with allelic frequencies ranging from 0.0010 to 0.5104. The combined discrimination power (CDP) and the combined probability of paternity (CPE) of 23 STR loci were 0.9999999999999999999999999996 and 0.999999999710422, respectively. Guizhou Tujia showed closer genetic relationships with Hubei Tujia, Guizhou Gelao, and Guizhou Miao than with other populations. Conclusion: We first obtained the population genetic data of Guizhou Tujia using the 23 STR system and demonstrated its value in forensic applications. Comprehensive population comparisons showed an evident genetic affinity pattern between populations that are geographically, ethnically and linguistically related.