Genetic polymorphism of 23 autosomal STR loci in Han population from Yuncheng, Shanxi Province.

Abstract

Objectives Due to the genetic feature of high diversity than other DNA markers, short tandem repeat (STR) plays key roles in forensic, anthropology, and population genetics. Newly introduced multiple STR kit is more valuable because of the greatly improved discriminatory power with the increase in the number of STR loci. The genetic polymorphic data are essential for the application and research in specific population. This study aims to investigate the genetic polymorphism of Han population residing in Yuncheng district, Shanxi Province, to evaluate the application of 23 STR loci in forensic personal identification and paternity test, and to explore the genetic relationship of Han population between Yuncheng and other populations. Methods A total of 23 STR loci were amplified from 525 healthy unrelated individuals from the Han nationality in Yuncheng, Shanxi Province using the AGCU EX25 amplification kit. The products were detected and separated by ABI 3500 Genetic Analyzer. Alleles were genotyped by GeneMapper ID (Version 3.2) software, and corresponding frequencies and forensic parameters were calculated. We calculated the genetic distance and plotted the neighboring-joining tree with other 13 population. Results The allele frequency of the 23 STRs ranged from 0.0010 to 0.5090. No deviation from Hardy-Weinberg equilibrium (P>0.05) and linkage disequilibrium was observed. The cumulative discriminatory power (CPD), cumulative power of exclusion for trios (CPEtrio)and cumulative Power of exclusion for duos (CPEduo) with total 23 STRs were 1-1.305 263 374 8×10-27, 1-2.583 152 052 2×10-10 and 1-1.193 637 500 4×10-6, respectively. Comprehensive population comparison showed that Shanxi Yuncheng Han nationality was genetically closer to populations of the same linguistic family or geographically close proximity, such as Shaanxi Weinan Han, Liaoning Han, and Ningbo Han nationality while relatively far away from different linguistic ethnic groups and geographically distant populations like Xinjiang Uygur and Guangdong Han nationality. Conclusions These 23 STRs are highly genetic polymorphic and informative in the Han population of Yuncheng, Shanxi Province, which can provide basic data for forensic personal identification, paternity testing, and population genetic research.