Objective: To investigate the genetic polymorphisms and their forensic application of 9 non-combined of DNA index system (CODIS) short tandem repeat(STR) loci in Guangdong Han population.
Methods: DNA samples from 500 unrelated individuals were extracted and amplified with fluorescence labeled multiplex PCR system. PCR products were separated and genotyped with capillary electrophoresis.
Results: One hundred and fifteen alleles and 160 genotypes were observed in the 9 STR loci, respectively. The heterozygosity was 0.824-0.884, the discrimination power (DP) was 0.925-0.969 and the polymorphism information content (PIC) was 0.77-0.86, respectively. The distribution met the Hardy-Weinberg equilibrium (P > 0.05). The total discrimination power was 1.00 x 10(-13), the combined probability of exclusion for trio-paternity testing was 0.999989488. The combined probability of exclusion for duo-paternity testing was 0.873436.
Conclusion: The 9 STR loci are powerful and reliable for personal identification and paternity testing. They can be used as supplementary loci in fatherless (motherless) testing or cases with mutation events.