Objective To evaluate the value of PowerPlex（R）21 System (Promega) and study the genetic polymorphism of its 20 short-tandem repeat (STR) loci in southern Chinese Han population.Methods We conducted genotyping experiments using PowerPlex(R)21 System on 20 autosomal STR loci (D3S1358,D1S1656,D6S1043,D13S317,Penta E,D16S539,D18S51,D2S1338,CSF1PO,Penta D,TH01,vWA,D21S11,D7S820,D5S818,TPOX,D8S1179,D12S391,D19S433 and FGA) in 2367 unre1ated Chinese Han individuals living in South China.The allele frequencies and parameters commonly used in forensic science were statistically analyzed in these individuals and compared with the reported data of other populations.Results The PowerPlex（R） 21 System had a power of discrimination (PD) ranging from 0.7839 to 0.9852 and a power of exclusion (PE) ranging from 0.2974 to 0.8099 for the 20 loci.No significant deviation from Hardy-Weinberg expectations was found for all the loci except for D5S818.This southern Chinese Han population had significant differences in the allele frequencies from 8 ethnic groups reported in China,and showed significant differences at 8 to 20 STR foci from 5 foreign populations.The allele frequency at the locus D1S1656 in this southern Chinese Han population differed significantly from those in the 5 foreign populations and from 3 reported Han populations in Beijing,Zhejiang Province and Fujian Province of China.The neighbor-joining phylogenetictree showed clustering of all the Asian populations in one branch,while the northern Italian and Argentina populations clustered in a separate branch.This southern Chinese Han population had the nearest affinity with the Yi ethnic population in Yunnan Province of China.Conclusion The 20 STR loci are highly polymorphic in this southern Chinese Han population,suggesting the value of this set of STR loci in forensic personal identification,paternity testing and anthropological study.

Objective To evaluate the value of PowerPlex（R）21 System (Promega) and study the genetic polymorphism of its 20 short-tandem repeat (STR) loci in southern Chinese Han population.Methods We conducted genotyping experiments using PowerPlex(R)21 System on 20 autosomal STR loci (D3S1358,D1S1656,D6S1043,D13S317,Penta E,D16S539,D18S51,D2S1338,CSF1PO,Penta D,TH01,vWA,D21S11,D7S820,D5S818,TPOX,D8S1179,D12S391,D19S433 and FGA) in 2367 unre1ated Chinese Han individuals living in South China.The allele frequencies and parameters commonly used in forensic science were statistically analyzed in these individuals and compared with the reported data of other populations.Results The PowerPlex（R） 21 System had a power of discrimination (PD) ranging from 0.7839 to 0.9852 and a power of exclusion (PE) ranging from 0.2974 to 0.8099 for the 20 loci.No significant deviation from Hardy-Weinberg expectations was found for all the loci except for D5S818.This southern Chinese Han population had significant differences in the allele frequencies from 8 ethnic groups reported in China,and showed significant differences at 8 to 20 STR foci from 5 foreign populations.The allele frequency at the locus D1S1656 in this southern Chinese Han population differed significantly from those in the 5 foreign populations and from 3 reported Han populations in Beijing,Zhejiang Province and Fujian Province of China.The neighbor-joining phylogenetictree showed clustering of all the Asian populations in one branch,while the northern Italian and Argentina populations clustered in a separate branch.This southern Chinese Han population had the nearest affinity with the Yi ethnic population in Yunnan Province of China.Conclusion The 20 STR loci are highly polymorphic in this southern Chinese Han population,suggesting the value of this set of STR loci in forensic personal identification,paternity testing and anthropological study.

Objective To validate the efficiency of 27-plex single nucleotide polymorphism (SNP) multiplex system for ancestry inference. Methods The 27-plex SNP system was validated for its sensitivity and species specificity. A total of 533 samples were collected from African, Southern Chinese Han, China's ethic minorities (Yi, Hui, Miao, Tibet, and Uygur), European, Central Asian, Western Asian, Southern Asian, Southeast Asian and South American populations for clustering analysis of the genotypes by citing 3 representative continental ancestral groups [East Asia (CHB), Europe (CEU), and Africa (YRI)] from HapMap database. Results The system sensitivity is 0.125 ng. Twenty and six genotypes were detected in chimpanzee and monkeys, respectively. Except in rs10496971, no more products were found in other animals. The system was capable of differentiating intercontinental populations but not of distinguishing between East Asian and Southeast Asian population or between Southern Chinese Han population and Chinese Ethnic populations (Hui, Miao, Yi and Tibet). This system achieved a 100%accuracy for intercontinental population source inference for 46 blind test samples. Conclusion 27-plex SNPs multiplex system has a high sensitivity and species specificity and can correctly differentiate the ancestry origins of individuals from African, European and East Asian for criminal case investigation. But this system is not capable of distinguishing subpopulation groups and more specific ancestry-informative markers are needed to improve its recognition of Southeast Asian and Chinese ethnic populations.

Objective To validate the efficiency of 27-plex single nucleotide polymorphism (SNP) multiplex system for ancestry inference. Methods The 27-plex SNP system was validated for its sensitivity and species specificity. A total of 533 samples were collected from African, Southern Chinese Han, China's ethic minorities (Yi, Hui, Miao, Tibet, and Uygur), European, Central Asian, Western Asian, Southern Asian, Southeast Asian and South American populations for clustering analysis of the genotypes by citing 3 representative continental ancestral groups [East Asia (CHB), Europe (CEU), and Africa (YRI)] from HapMap database. Results The system sensitivity is 0.125 ng. Twenty and six genotypes were detected in chimpanzee and monkeys, respectively. Except in rs10496971, no more products were found in other animals. The system was capable of differentiating intercontinental populations but not of distinguishing between East Asian and Southeast Asian population or between Southern Chinese Han population and Chinese Ethnic populations (Hui, Miao, Yi and Tibet). This system achieved a 100%accuracy for intercontinental population source inference for 46 blind test samples. Conclusion 27-plex SNPs multiplex system has a high sensitivity and species specificity and can correctly differentiate the ancestry origins of individuals from African, European and East Asian for criminal case investigation. But this system is not capable of distinguishing subpopulation groups and more specific ancestry-informative markers are needed to improve its recognition of Southeast Asian and Chinese ethnic populations.