Genetic Polymorphism Investigation of 19 X-STR Loci in the Han Population in Northern China

To investigate the genetic polymorphisms of 19 X-STR loci in the Han population in Northern China, samples from 628 unrelated individuals (314 males and 314 females) were collected and 19 X-STR loci were amplified by AGCU X19 STR System. A total of 270 different alleles were detected in 19 X-STR loci. All loci were in Hardy − Weinberg equilibrium and there was only one pair of linkage loci (DXS10103-DXS10101). There was no significant difference in allele frequency between male and female populations. The combined power of discrimination in males was 1–1.8667 × 10−13, while the combined power of discrimination in females was 1–3.6532 × 10−22. The combined mean paternity exclusion chance (CMEC) for X-chromosomal markers in father/daughter or mother/son duos Mean paternity exclusion chance (MECDesmarais Duo) was 1–5.1109 × 10−9. Moreover, the CMEC for X-chromosomal markers in trios involving daughters (MECDesmarais) was 1–2.0292 × 10−12. The compound amplification system composed of 19 X-STR in this study showed high polymorphism in the Han population of Northern China, which had a high application value in difficult genetic relationship identification.