Genetic polymorphisms of 23 STR loci of Goldeneye™ 25A kit in Shandong Han population

A Tibetan group from Ngawa Tibetan and Qiang Autonomous Prefecture, southwest China, is rich in genetic polymorphisms at 36 autosomal STR loci and shares a complex genetic structure with other Chinese populations

The Tibetan people are ancient and populous, constituting the seventh-largest of the fifty-five ethnic minority groups in China. The Ngawa Tibetan and Qiang Autonomous Prefecture (NTQAP), situated on the border of northwest and southwest China, has its distinct group relationships. Short tandem repeat (STR) is extremely polymorphic and extensively used in the application of forensic medicine and population genetics. However, it is not clear the genetic information including linkage disequilibrium (LD) by 36 autosomal STR (A-STR) markers in the Tibetan group from NTQAP. The Tibetan population from NTQAP of southwest China was examined for 36 A-STR loci in the research. Every marker across the 36 A-STR loci was consistent with Hardy-Weinberg equilibrium (HWE). The results of the calculation revealed that the total discrimination power (TDP) is 1-2.2552 × 10-42 and the cumulative probability of exclusion (CPE) is 1-1.3031 × 10-16. Subsequently, a total of 345 alleles with allelic frequencies ranging from 0.00382 to 0.55343 were identified, and the allelic numbers varied from 5 in both the TH01 and TPOX markers to 28 in the SE33 locus. The Ngawa Tibetan population, along with other Chinese populations, exhibited influences from historical factors and regional distribution, as indicated by the results of population genetics analysis. We thus first explored the genetic characteristics and correlated forensic parameters of the 36 A-STR markers in NTQAP to fill the gap in the Tibetan population. It was discovered that these 36 autosomal STR markers supplemented forensic STR databases and offered extremely valuable polymorphisms for Chinese forensic applications, such as parentage testing and personal identification. Moreover, the study would contribute additional information regarding the substructure and diversity in the Chinese population.

Genetic Polymorphism and Population Genetic Structure Analysis of 21 Autosomal STR Loci for a Han-Chinese Population from Luzhou of Southwest China

The Han nationality is an ancient and populous people, and different places in China may have their distinct group relationships. Luzhou area, as a crossroads of several provinces in Southwest China, lacks autosomal short tandem repeat (STR) research and population genetics research. In this study, 21 autosomal STR loci were evaluated in 1959 Han-Chinese individuals from Luzhou area. There was no substantial linkage disequilibrium (LD) among the 21 autosomal STR markers, and all markers were in Hardy-Weinberg equilibrium (HWE). The total discrimination power (TDP) and cumulative probability of exclusion (CPE) of the 21 autosomal STR loci were calculated to be 1-9.8505 × 10^-16 and 1-1.9406 × 10^-9, respectively. There were 333 alleles for 21 STRs with allelic frequencies ranging from 0.00026 to 0.51302, and the number of alleles ranged from 7 in locus TPOX to 29 in locus Penta E. According to the results of population comparison and population differentiation, historical influences, geographical distribution, cultural integration, and economic development may have an impact on the Luzhou Han population and other Chinese populations. These 21 STR loci were found to enrich autosomal STR information in forensic databases and provide highly informative polymorphisms for our forensic practice in China, including personal identification and parentage testing.

Genetic and structural characterization of 20 autosomal STR loci from the Henan Han population of central China

AIM

This study was designed to investigate the genetic polymorphisms and forensic parameters of the 20 autosomal short tandem repeat (STR) loci included in the PowerPlex® 21 System (Promega, USA) in the Henan Han population with a view to expand the genetic information available for this population in human genome databases.

SUBJECTS AND METHODS

We evaluated the genetic polymorphisms from 20 autosomal STR loci using DNA typing based on 2995 individuals from the Henan Han population in central China and then used this information to investigate the genetic relationships between this population and the other 10 Han populations across China. These comparisons included genetic distance, phylogenetic trees, and principal component analysis (PCA).

RESULTS

We identified a total of 290 alleles and 1343 genotypes within the Henan Han population, with none of these loci deviating from their Hardy-Weinberg equilibrium (HWE). The population comparisons revealed that geographically close populations demonstrated closer genetic relationships. Thus, the Henan Han population was shown to be close to both the Beijing Han and Tianjin Han populations, creating a single cluster. In addition, these 20 STR loci exhibited a high degree of genetic polymorphisms, making them suitable for individual identification and parentage testing.

CONCLUSIONS

The results of this study will enrich the forensic databases of Chinese Han populations and serve as a resource for further studies in these populations.