Genetic polymorphisms of 12 X-STR for forensic purposes in Shanghai Han population from China

X-chromosomal short tandem repeats (X-STR) loci are used for forensic practice in recent years in some complex kinship cases. The commercially available kit of Investigator Argus X-12 (Qiagen, Hilden, Germany) makes it possible to examine the markers of DXS10148-DXS10135-DXS8378, DXS7132-DXS10079-DXS10074, DXS10103-HPRTB-DXS10101 and DXS10146-DXS10134-DXS7423, which belong to four linkage groups of X-chromosome. In this study, a total of 309 unrelated individuals (200 males and 109 females) from Shanghai Han population were successfully analyzed with this kit. Hardy-Weinberg equilibrium tests demonstrated no significant deviation from expected values (P > 0.05) for all of the 12 X-STR loci in the Shanghai Han population. Linkage disequilibrium tests were performed for all pairs of loci by the Arlequin v3.1 software and only DXS10103-DXS10101 remained significant after adjustment for multiple testing (P < 0.05/66). The combined power of discrimination in males (CDPM) was 0.999999996 while in females (CDPF) was 0.999999999999995, and the combined mean exclusion chance in duo cases (CMECD) was 0.999998 while in trio cases (CMECT) was 0.999999986. The results suggest that the twelve X-STR loci may provide high polymorphic information for paternity testing and forensic identification in Chinese Han population from Shanghai.