Forensic features and genetic structure of 20 autosomal STR loci in the Han population of Ningde City, Southeastern China

Short tandem repeat (STR) loci are widely used in forensic medicine and population genetics. To profile 20 autosomal STR loci using the SureID^® 21 G Human STR Identification Kit. Samples were obtained from 1412 unrelated Chinese Han individuals from Ningde City, Southeastern China and 20 autosomal STR loci were profiled using the SureID^® 21 G Human STR Identification Kit. A total of 261 alleles were observed among 1412 unrelated individuals and the corresponding allelic frequencies ranged from 0.5464 to 0.0004. The combined power of discrimination and exclusion of the 20 autosomal STR loci were 0.99999999999999999922 and 0.999999340285752, respectively. There was no significant deviation from Hardy–Weinberg equilibrium (HWE) and minimal departure from linkage equilibrium (LE) for two pairwise combinations of loci after sequential Bonferroni correction. In the population comparison, phylogenetic analysis was performed between the Han population and other relevant populations on the basis of the shared autosomal STR genotyping. Moreover, the neighbor-joining tree and principal component analysis were analysed based on the Nei’s standard genetic distance. The population comparison revealed that the structure of the Ningde Han population was similar to the structure of southern Han populations in China and was significantly different to the other Chinese ethnic groups, such as Kyrgyz, Uzbek, Kazakh, Uyghur, Manchu from Xinjiang and Mongols.