[The establishment of a nine X-chromosome short tandem repeat loci multiplex PCR and detection of the polymorphism of these loci].

OBJECTIVE

To establish a nine X-chromosome short tandem repeats (X-STR) loci multiplex PCR method and study the polymorphism of the 9 X-STR loci,and to determine its application in kinship tests for forensic medicine.

METHODS

A fluorescent multiplex PCR that simultaneously amplifies 9 X-STR loci, i.e. DXS7133, DXS981, DXS7424, DXS6789, DXS7132, GATA165B12, DXS101, GATA31E08 and DXS10011, were set up. PCR products were analyzed using capillary electrophoresis and ABI prism 3100 Genetic Analyzer with GeneMapper ID 3.1 analysis software.

RESULTS

When 251 unrelated male and 112 unrelated female individuals from southern China were tested, 111 alleles were detected. The power of discrimination in females was 0.5837-0.9959. Mean exclusion chance for X-STR in standard trios with daughters was 0.4072-0.9511. Polymorphism information content was 0.4481-0.9531.

CONCLUSION

The results demonstrate that the 9 loci in the multiplex system provide high polymorphism information, and the multiplex system provides a fast technology for forensic identification and paternity testing. The X-STR multiplex system can complement the analysis of AS-STR and Y-STR efficiently.