Genetic polymorphisms of nine X chromosome STR loci in an Inner Mongolia Daur population and their forensic evaluation

Objective: To investigate the allele and genotype frequencies of nine short tandem repeat (STR) loci on the X chromosome (DXS6789, DXS101, DXS8378, DXS7132, DXS7133, DXS7423, DXS6804, DXS6799 and HPRTB) of Daur individuals living in Inner Mongolia Autonomous Region of China. Methods: The nine X-chromosomal STR loci were analyzed with PCR, followed by polyacylamide gel electrophoresis and silver staining. Software SPSS13.0, Genepop, Fstat and Powerstats were used to evaluate their polymorphism diversity and potential forensic application. Results: We obtained allelic and genotypic frequencies for nine X-chromosomal STR in eighty-seven unrelated Daur individuals. Among the nine loci, DXS7133 showed less polymorphism and gene diversity in Daur population. Results of locus-to-locus comparisons showed that DXS7423 and DXS7132 had no significant differences between Daur population and other four Asian populations (Han, Hui, Tibetan and Korean). Conclusion: Except DXS7133, the other eight X-chromosomal STR loci are appropriate for individual identification, paternity test involving a female child, and disease-related studies.