Genetic variation and phylogenetic analysis of 23 STR in Chinese Han population from Hainan, Southern China

The forensic characteristics and genetic relationships of Hainan Han population are still not fully understood. The aim of this study was to investigate the forensic features and genetic variations of 23 short tandem repeat (STR) included in the HuaxiaTM Platinum system in Hainan Han and analyze the population genetic relationships between Hainan Han and other adjacent Chinese populations. The genetic polymorphisms of 23 STR loci included in the HuaxiaTM Platinum kit were evaluated from 2971 Hainan Han individuals. Comprehensive comparisons were conducted based on genetic distance, phylogenetic tree, multidimensional scaling and principal component analysis (PCA) to explore inter-population genetic relationship. The combined power of discrimination (CPD) and the combined power of exclusion (CPE) of the 23 STR loci was 0.999 999 999 999 999 999 999 999 999 819 and 0.999 999 999 625 408, respectively. The investigated Hainan Han population has high genetic similarity with geographically close Han populations, while great genetic difference with other ethnic minorities, prominently in Yunnan Miao, Xinjiang Uygurs, Xinjiang Kazakh, and Tibetans. Our study found the 23 STR loci were highly polymorphic and suitable for forensic personal identification and paternity testing in Hainan Han population. Genetic similarity widely existed among Han populations from different regions, and significant genetic divergence existed between Han populations and some ethnic minorities. The populations genetic diversity and similarity were closely associated with ethnic origin and geographical distribution.