[A population genetic study of 22 autosomal loci of single nucleotide polymorphisms].

OBJECTIVE: To evaluate polymorphisms and forensic efficiency of 22 non-binary single nucleotide polymorphism (SNP) loci. METHODS: One hundred ethnic Han Chinese individuals were recruited from Dongguan, Guangdong. The 22 loci were genotyped with matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS). RESULTS: Nine loci were found with a single allele, 4 loci were found to be biallelic, whilst 9 loci were found to have 3 alleles. For 13 polymorphic loci, the combined discrimination power and power of exclusion were 0.999 98 and 0.9330, respectively. For the 9 non-biallelic loci, the combined discrimination power and power of exclusion were 0.9998 and 0.8956, respectively. For motherless cases, the combined power of exclusion was 0.6405 for 13 polymorphic SNPs and 0.6405 for 9 non-binary SNPs. CONCLUSION: Non-binary loci have a greater discrimination power and exclusion power per SNP.

[Genetic polymorphisms of fifteen short tandem repeat loci in Guilin Han population].

OBJECTIVE: To investigate the genetic polymorphisms of 15 short tandem repeat (STRs) in Guilin Han population. METHODS: DNA was extracted by Chelex method, and 15 STRs were analyzed using AmpFISTR Identifiler kit. RESULTS: Four rare alleles, namely FGA * 10, D2S1338 * 10, D3S1358 * 16.2 and D3S1358 * 17.2, were observed. The combined match probability and exclusion probability for the 15 STRs were 2.89 x 10(-17) and 0.9999993, respectively. CONCLUSION: These STRs have good discrimination power and exclusion probability in Guilin Han population.

Assessing forensic applications of the frontal sinus in a Chinese Han population.

The frontal sinus is an important tool of personal identification. To assess the forensic applications of the frontal sinus patterns in a Chinese Han population, 198 individuals were analyzed. 165 individuals who have the frontal sinus were observed in this population, and 12 parameters of the frontal sinus were observed according to Yoshino's method. The same combined code was found in three persons from our samples. The unilateral frontal sinus scalloped with one arcade has few parameters applied to personal identification, and shows the poorer discrimination power. These parameters showed better discrimination power in our population, and could be applied to personal identification.

[Polymorphism of 22 Y-STR loci in Guangdong Han population and genetic relationship with 12 populations].

To investigate the genetic polymorphisms of 22 Y-chromosomal short tandem repeats(STR) loci in Guangdong Han population, and to evaluate their forensic application values and genetic relationships with 12 other populations. These Y-STR loci (DYS19, DYS389/, DYS390, DYS391, DYS392, DYS393, DYS385, DYS437, DYS438, DYS439, DYS461, DYS481, DYS504, DYS505, DYS508, DYS533, DYS576, DYS588, DYS607, DYS634, and DYS643) were analyzed in 216 unrelated healthy Guangdong Han individuals by three multiplex PCR systems including the PowerPlex Y System. Cluster analysis and phylogenic trees were applied to show the genetic distance among the populations. As a result, a total of 214 haplotypes were identified and the overall haplotype diversity for the 22 Y-STR loci was 0.9999. The gene diversity values (GD) for each locus ranged from 0.3299 (DYS634) to 0.9425 (DYS385). Comparing with 12 other populations, the genetic distance between Guangdong and Chaoshan Han population was the smallest (-0.0030), while that between Guangdong and Northeast Han Chinese was the largest (0.0195). The phylogenetic tree was similar to the results of clustering analysis. Multiplex detection of the 22 Y-STR loci revealed a highly polymorphic genetic distribution, which would be very powerful for establishing a Y-STR database, for population genetics and forensic practice.

Haplotypes of 20 Y-chromosomal STRs in a population sample from southeast China (Chaoshan area).

In this study, 20 Y-specific short tandem repeat (STR) loci (DYS434, Y-GATA-A10, Y-GATA-H4, DYS438, DYS439, DYS443, DYS444, DYS446, DYS447, DYS448, DYS456, DYS458, DYS460, DYS520, DYS531, DYS557, DYS622, DYS630, DYS635(Y-GATA-C4), and DYS709) were analyzed in 158 unrelated healthy men from southeast China by three fluorescence-labeled multiplex polymerase chain reaction systems. The Y-STR multiplexes developed have followed the published nomenclature and International Society for Forensic Genetics (ISFG) guidelines for STR analysis. Gene diversity ranged from 0.2506 at DYS434 to 0.8034 at DYS447. A total of 157 different haplotypes were observed, and among these, 156 were unique, while 1 was found two times. The haplotype diversity value calculated from all 20 loci combined was 0.9997, which is informative. Furthermore, 80 father-son pairs, previously confirmed by autosomal STR analysis, were typed using the same 20 Y-STR loci, and four mutation events were identified at the Y-GATA-H4, DYS439, DYS456, and DYS458 loci, giving an average mutation rate of 0.25% per locus per generation (95% confidence interval 0.09-0.54). These results including the haplotype data at 20 Y-STR loci would enrich Chinese genetic informational resources and provide useful information in forensic practice.

Genetic analysis of six STR polymorphisms in a southern Chinese population.

POPULATION: A total of 105 unrelated and healthy individuals from the Han ethnic group of Nanning city in south China.

[Distributions of haplotypes for three Y-STR loci in a Tibetan ethnic group of Chinese population by using Y-STR multiplexes].

OBJECTIVE: One multiplex genotyping system was developed in using silver staining with allelic ladders for three Y-chromosome STR markers (DYS434, DYS443, and DYS456), with a view towards the application of rapid and simple genotyping assay methods for DNA profiling. The distributions of haplotypes for three Y-STR loci(DYS434, DYS443, and DYS456) was investigated in a Tibetan ethnic group of Chinese population. METHODS: Allele and haplotype frequencies at these Y-STRs loci(DYS434, DYS443, and DYS456) were analysed by PCR amplification using Y-STR multiplexes, followed by horizontal non-denaturing polyacrylamide gelelec-trophoresis in 101 unrelated males of Tibetan ethnic group in Lasa of China. RESULTS: A total of 31 different haplotypes were found, 16 of them being unique. The haplotype diversity value (which is the same as the discrimination index) calculated from all three loci combined was 0.9481, which is informative. CONCLUSION: The Y-STR multiplexes provide useful information for forensic analysis and paternity tests and can also be of great benefit for providing information not normally available from autosomal DNA systems.

Characterization of eight Y-STR loci and haplotypes in a Chinese Han population.

In this study we analyzed the eight Y-STR loci, DYS443, DYS444, DYS448, DYS453, DYS455, DYS456, DYS457 (DYS437) and DYS458, investigated haplotype distributions of these Y-STR loci in a Chinese Han population, and sequenced alleles of the eight loci for clarifying the structure. Extracted DNA was amplified by PCR and the PCR products were analyzed by non-denaturing horizontal polyacrylamide gel electrophoresis with a discontinuous buffer system. Alleles were sequenced on an ABI 3700 using a Dye Terminator Cycle sequencing kit. DYS443, DYS453, DYS455 and DYS456 were found to be simple repeat systems, while DYS444, DYS448, DYS457 (DYS437) and DYS458 were complex repeat systems. The gene diversities of DYS443, DYS444, DYS448, DYS453, DYS455, DYS456, DYS457 (DYS437) and DYS458 were 0.7742, 0.7671, 0.7453, 0.3545, 0.0549, 0.6988, 0.6148 and 0.8213, respectively. The haplotype diversity for 8 Y-STR loci was 0.9996, and the discrimination capacity was 0.9815. The results indicate that these eight loci are useful Y-linked markers for forensic applications.