Genetic profile characterization and population study of 21 autosomal STR in Chinese Kazak ethnic minority group

Efficiency evaluation of common forensic genetic markers for parentage identification involving close relatives

To explore the efficacy of commonly used forensic identification panels in complex paternity testing of trios that involved close relatives, we wrote a code by R to generate 10,000 pedigrees at 20 CODIS STR, 21 non-CODIS STR and 30 InDel loci in Chinese five ethnic groups based on their allele frequencies. Parentage identification index--cumulative paternity index (CPI) value was set as output and was further analyzed to evaluate the performance of the aforementioned panels in complex paternity testing when the alleged parent is a random individual, biological parent, grandparent, sibling of biological parent, half-sibling of biological parent, etc. The results showed that the false inclusion of parent sibling posed as parent demonstrated no statistically significant difference from that of grandparent posed as parent. The scenarios where both biological parent and alleged parent were consanguineous to the other parent were also simulated. The results revealed that the complexity of paternity testing would raise when biological parents were consanguineous and the alleged parent was a close relative of theirs. Despite the values of non-conformity number could vary in different genetic relationships, populations and panels, 20 CODIS STRs and 21 non-CODIS STRs performed satisfactorily in most simulated scenarios. However, the joint use of 20 CODIS STRs and 21 non-CODIS STRs is more recommendable when resolving the paternity testing of the incest mating case. Overall, the current study could be regarded as a worthwhile reference in complex paternity testing of trios that involved close relatives.

Myopia prevalence and ocular biometry: a cross-sectional study among minority versus Han schoolchildren in Xinjiang Uygur autonomous region, China

Objectives

To describe and compare the prevalence of refractive error and its associated ocular biometric parameters in a large multi-racial sample of schoolchildren from Xinjiang.

Methods

A total of 67,102 school children of five ethnicity groups aged 6–23 years from 46 schools in Xinjiang participated in this study. The children underwent a comprehensive eye examination for vision screening, including uncorrected visual acuity and standardized refraction. Refractive error was determined by autorefractors and subjective refraction. Refraction was recorded in spherical equivalent (SE). The age- and sex- adjusted prevalence of myopia (SE ≤ −0.5 D), low myopia (−6 D < SE ≤ −0.5 D), high myopia (SE ≤ −6.0 D), astigmatism (cylinder < −0.5 D), and anisometropia (difference in SE between two eyes of 1.0 D) in the five ethnic groups were calculated. Ocular biometric parameters including axial length (AL) and corneal radius of curvature (CR) were measured by AL-scan optical biometer.

Results

The age- and sex- adjusted prevalence of myopia in the Han, Hui, Uyghur, Kyrgyz and Kazakh were 65.8% (95% confidence interval [CI] 65.4, 66.3); 59.1% (95% CI 57.8, 60.4); 30.1% (95% CI 29.2, 30.9); 30.2 (95% CI 28.9, 31.4); and 30.0% (95% CI 27.6, 32.3), respectively. The Han and Hui children also had longer ALs (Han, 23.8; Hui, 23.6, Uyghur, 23.1; Kyrgyz, 23.1; Kazakh, 23.3 mm) and larger AL/CR (Han, 3.04; Hui, 3.00; Uyghur, 2.95; Kyrgyz, 2.96; Kazakh, 2.97) values than the other three minorities (P < 0.01). Overall, girls had shorter ALs, steeper corneas, and smaller AL/CR values than boys (P < 0.01).

Conclusions

Significant ethnic difference in the prevalence of myopia was observed in this study on school-aged children in Xinjiang (Han > Hui > Kyrgyz > Uyghur > Kazakh). This study among different ethnic groups in a multiethnic population is valuable for enriching the ethnical information resources for refractive errors and ocular biometry parameters, as well as facilitating further research on myopia-related diseases and risks.

Diversities of HLA-A, -B, -C, -DRB1 and -DQB1 loci in Chinese Kazak population and its genetic relatedness dissection with multiple populations: a comparative study

Studying the allele and haplotype distributions of human leukocyte antigen (HLA) loci at 2nd-field level in different populations was important. Allele and haplotype frequencies of HLA-A, -B, -C, -DRB1 and -DQB1 loci in 110 unrelated healthy Kazak individuals living in Xinjiang (China) were analyzed using polymerase chain reaction sequence based typing. Thirty HLA-A, 48 HLA-B, 24 HLA-C, 34 HLA-DRB1 and 18 HLA-DQB1 alleles were detected at the 2nd-field level in the Kazak population. Frequencies of HLA alleles, genotypes, and haplotypes were calculated, and some exhibited significantly different distributions among different populations. A neighbor-joining (NJ) tree, heatmap, multidimensional scaling (MDS) and principal component analysis (PCA) were used to explore the genetic relationships between the Kazak population and 32 reference populations distributed in Asia, Africa, America and Europe using frequency data of HLA-A, -B, -C and -DRB1 loci. The NJ tree, heatmap, and MDS of the 33 populations were constructed based on pairwise D_A values of populations obtained by the HLA-A, -B, -C and -DRB1 allele frequencies. Different PCA plots were constructed based on the allele frequencies of HLA-A, -B, -C and -DRB1 or estimated haplotypic frequencies of HLA-A, -B, -C loci. The data obtained in the present research can be used for research on HLA-related diseases or paternity relationships, and aid to finding the best matched donors in stem cell transplantation for Kazak individuals.

Forensic features and genetic structure of 20 autosomal STR loci in the Han population of Ningde City, Southeastern China

BACKGROUND

Short tandem repeat (STR) loci are widely used in forensic medicine and population genetics.

AIM

To profile 20 autosomal STR loci using the SureID^® 21 G Human STR Identification Kit.

SUBJECTS AND METHODS

Samples were obtained from 1412 unrelated Chinese Han individuals from Ningde City, Southeastern China and 20 autosomal STR loci were profiled using the SureID^® 21 G Human STR Identification Kit.

RESULTS

A total of 261 alleles were observed among 1412 unrelated individuals and the corresponding allelic frequencies ranged from 0.5464 to 0.0004. The combined power of discrimination and exclusion of the 20 autosomal STR loci were 0.99999999999999999922 and 0.999999340285752, respectively. There was no significant deviation from Hardy-Weinberg equilibrium (HWE) and minimal departure from linkage equilibrium (LE) for two pairwise combinations of loci after sequential Bonferroni correction. In the population comparison, phylogenetic analysis was performed between the Han population and other relevant populations on the basis of the shared autosomal STR genotyping. Moreover, the neighbor-joining tree and principal component analysis were analysed based on the Nei's standard genetic distance.

CONCLUSION

The population comparison revealed that the structure of the Ningde Han population was similar to the structure of southern Han populations in China and was significantly different to the other Chinese ethnic groups, such as Kyrgyz, Uzbek, Kazakh, Uyghur, Manchu from Xinjiang and Mongols.

Comprehensive analyses for genetic diversities of 19 autosomal STRs in Chinese Kazak group and its phylogenetic relationships with other continental populations

Short tandem repeats (STRs) play an essential role in forensic genetics due to their high degree of polymorphisms, wide distributions and easy detection method. In this study, allelic frequencies and forensic statistical parameters of the 19 autosomal STR loci in a Kazak ethnic group were calculated, and its genetic relationships with reference populations were assessed in order to understand population structure better and enrich population genetic data for forensic practice in Chinese Kazak ethnic group. There were 226 identified alleles with the corresponding allelic frequencies ranging from 0.0008 to 0.5295 in the 628 unrelated healthy Kazak individuals in Xinjiang Uygur Autonomous Region. All autosomal STRs were conformed to the Hardy-Weinberg equilibrium after Bonferroni’s correction. The cumulative power of discrimination and the combined probability of exclusion of all the 19 autosomal STRs were 0.999 999 999 999 999 999 999 997 162 and 0.999 999 994 484, respectively. Furthermore, the D_A distances and Fixation index values of pairwise populations, principal component analysis, multidimensional scaling analysis, phylogenetic tree analysis and structure analysis were conducted to probe the genetic relationships between the Kazak group and other reference populations. The population genetic results showed that these 19 autosomal STR loci were characterised by high genetic diversities in the Kazak group. Furthermore, the studied Kazak group had close genetic relationships with the Uyghur group and the Uzbek group. The present results may facilitate understanding the genetic background of the Chinese Xinjiang Kazak group.

Genetic polymorphism and phylogenetic analyses of 21 non-CODIS STR loci in a Chinese Han population from Shanghai

BACKGROUND

Short tandem repeats (STRs) are essential genetic markers for forensic applications and population estimations; thus the population genetics of STR loci have been extensively studied and discussed.

METHODS

In the present study, we detected 21 autosomal noncombined DNA index system (non-CODIS) STR loci in a Chinese Han population from Shanghai, calculated their forensic parameters and analyzed their genetic relationships with reported reference populations in mainland China.

RESULTS

A total of 173 alleles were observed, with corresponding allele frequencies from 0.0020 to 0.5512. The cumulative power of discrimination (CPD) and the cumulative probability of exclusion (CPE) values of the 21 STR loci were 0.999999999999999999997337058271 and 0.99999953732495, respectively. The results of interpopulation differentiation, phylogenetic, multidimensional scaling, and structure analyses indicated a closer genetic relationship of the studied population with Han populations from other regions of China than with other populations.

CONCLUSIONS

The 21 STR loci exhibited high genetic polymorphism in the studied Shanghai_Han population and could be used for forensic applications and population genetic studies.

Genetic affinity between Ningxia Hui and eastern Asian populations revealed by a set of InDel loci

According to historical records, ethnic Hui in China obtained substantial genetic components from western Eurasian populations during their Islamization. However, some scholars believed that the ancestry of Hui people were native Chinese populations. In this context, the formation of Hui is due to simple cultural diffusion rather than demic diffusion. In this study, we examined the forensic and population genetic application of the 30 InDel loci in Hui population from Ningxia Hui Autonomous Region, Northwest China. Genotype analysis of 129 unrelated individuals revealed that all loci were in the Hardy-Weinberg equilibrium in Ningxia Hui. Forensic indices calculated from genotypes demonstrated that this panel, Qiagen DIPplex® Investigator kit, was powerful enough to be used in individual identification but not in paternity cases. Through population genetic analysis, we found that Ningxia Hui received much more genetic contributions from East Asian populations than those from western Eurasian populations. Finally, we statistically identified the admixture signal of eastern and western Eurasians, although the latter is weak, in Ningxia Hui via the three-population test. All this evidence suggested that the formation of Ningxia Hui was mainly attributed to the cultural transformation of local Chinese residents with minor gene flow from western Eurasian populations.

Genetic diversity of 23 STR loci in Guangxi Zhuang population and its phylogenetic relationship with 25 other populations

Aim: To estimate genetic diversity of 23 STR loci included in the DNA Typer^TM 25 Kit, and evaluate its effectiveness in forensic application.Subjects and methods: A total of 450 (251 males and 179 females) unrelated healthy individuals from Guangxi Zhuang population were amplified with DNA Typer^TM 25 Kit, isolated by the 3730 Series Genetic Analyzer^TM, and genotyped using the GeneMapper ID-X. Genetic parameters and population relationships were analysed.Results: Allele frequencies ranged from 0.001 to 0.5889. The combined power of discrimination (CPD) and the combined power of exclusion (CPE) of the 23 STR loci were 0.999999999999999999 and 0.999996765, respectively. No deviations from Hardy-Weinberg equilibrium and linkage disequilibrium were observed. Inter-population comparison based on Fst, PCA, genetic distance, phylogenetic trees, and MDS showed that Zhuang population clustered with the populations holding a close geographic distance with Zhuang (Guangdong Han and Hainan Li populations).Conclusions: Our study indicated that the 23 autosomal STR loci included in DNA Typer^TM 25 Kit can be used as forensic tools for individual identification and parentage testing. Moreover, the result of our mass investigation will enrich the forensic database of Chinese populations and serve for further study of the origin of anthropology.

Development of a new 25plex STRs typing system for forensic application

We have developed a novel STR 25-plex florescence multiplex-STR kit (DNATyper25) to genotype 23 autosomal and two sex-linked loci for forensic applications and paternity analysis. Of the 23 autosomal loci, 20 are non-CODIS. The sex-linked markers include a Y-STR locus (DYS391) and the Amelogenin gene. We present developmental validation studies to show that the DNATyper25 kit is reproducible, accurate, sensitive, and robust. Sensitivity testing showed that full profiles were achieved with as low as 125 pg of human DNA. Specificity testing demonstrated a lack of cross reactivity with a variety of commonly encountered non-human DNA contaminants. Stability testing showed that full profiles were obtained with humic acid concentration ≤60 ng/μL and hematin concentration <400 μM. For forensic evaluation, the 23 autosomal STRs followed the Hardy-Weinberg equilibrium. In an analysis of 509 Chinese (CN) Hans, we detected a combined total of 181 alleles at the 23 autosomal STR loci. Since these autosomal STRs are independent from one another, PM was 8.4528 × 10^-22 , TDP was 0.999 999 999 999 999 999 999, CEP was 0.999 999 8395. The forensic efficiency parameters demonstrated that these autosomal STRs are highly polymorphic and informative in the Han population of China. We performed population comparisons and showed that the Northern CN Han has a close genetic relationship with the Luzhou Han, Tujia, and Bai populations. We propose that the DNATyper25 kit will be useful for cases where paternity analysis is difficult and for situations where DNA samples are limited in quantity and low in quality.

Forensic characteristics and population genetics of Chinese Kazakh ethnic minority with an efficient STR panel

On the purpose of enhancing the forensic efficiency of CODIS STR loci, new STR loci have been gradually discovered and developed into some commercial multiplex systems. Recently, 22 STR loci including 18 non-CODIS STR loci and four CODIS STR loci were investigated in 501 unrelated healthy individuals of Kazakh ethnic group. Seven to 20 alleles at the different loci were identified and altogether 276 alleles for 22 selected loci were detected with the corresponding allelic frequencies ranging from 0.0010 to 0.3623. No significant deviation was observed from the Hardy-Weinberg equilibrium test for any of the 22 STRs. The value of cumulative power of discrimination in Kazakh group was 1-1.00E^-28. Analyses of population differentiations and genetic distances between Kazakh and other Chinese groups presented that the Kazakh group with the Uygur group. These 22 STR loci evenly distributed on 22 different autosomal chromosomes were characterized by high genetic diversities and therefore could be utilized in the forensic cases to further increase the discrimination performance.

Forensic characteristics and phylogenetic structure of Eastern Chinese Han populations residing along the Yangtze Basin revealed by 19 autosomal STR loci

In present study, forensic parameters based on the population data of nineteen autosomal short tandem repeats (STRs) loci were estimated in Chinese Han populations from three riverfront areas of Yangtze Basin in Eastern China. The combined power of discrimination (CPD) were 0.9999999999999999999999883, 0.9999999999999999999999846 and 0.9999999999999999999999863, respectively. The combined power of exclusion (CPE) were 0.999999992248957, 0.999999989800400 and 0.999999989799819, respectively. Furthermore, the genetic relationships among our studied populations and 32 previously investigated populations residing in other areas of China were also analyzed based on pairwise genetic distances (F_ST). The multidimensional scaling (MDS) plot and phylogenetic tree indicated that our studied populations were majorly clustered with the Han populations along the Yangtze Basin and populations to the north of it. In summary, our results supported that the 19 autosomal STR loci, which were polymorphic and informative in forensic identification, could also be applied in population genetics studies.

Forensic efficiency estimate and phylogenetic analysis for Chinese Kyrgyz ethnic group revealed by a panel of 21 short tandem repeats

Short tandem repeats (STRs) with a high level of polymorphisms and convenient detection method play an indispensable role in human population and forensic genetics. Recently, we detected the 21 autosomal non-combined DNA index system (non-CODIS) STR loci in a Kyrgyz ethnic group, calculated their forensic parameters and analysed its genetic relationships with reference populations from China. In total, 168 alleles were observed at 21 non-CODIS STRs with corresponding allelic frequencies from 0.0016 to 0.4788. No significant deviations at these STRs were observed from the Hardy-Weinberg equilibrium. The values of cumulative power of discrimination and probability of exclusion for all the 21 non-CODIS STRs were 0.99999999999999999998835 and 0.9999994002, respectively. Furthermore, the analyses of phylogenetic trees, genetic distances and interpopulation differentiations demonstrated that the Kyrgyz group had relatively close genetic relationships with the Uygur and Kazak groups. These 21 non-CODIS STRs were characterized by high genetic diversities in the Kyrgyz group and could be applied as a robust tool for individual identification and kinship testing in forensic sciences.

Genetic diversity and phylogenetic characteristics of Chinese Tibetan and Yi minority ethnic groups revealed by non-CODIS STR markers

Non-CODIS STRs, with high polymorphism and allele frequency difference among ethnically and geographically different populations, play a crucial role in population genetics, molecular anthropology, and human forensics. In this work, 332 unrelated individuals from Sichuan Province (237 Tibetan individuals and 95 Yi individuals) are firstly genotyped with 21 non-CODIS autosomal STRs, and phylogenetic relationships with 26 previously investigated populations (9,444 individuals) are subsequently explored. In the Sichuan Tibetan and Yi, the combined power of discrimination (CPD) values are 0.9999999999999999999 and 0.9999999999999999993, and the combined power of exclusion (CPE) values are 0. 999997 and 0.999999, respectively. Analysis of molecular variance (AMOVA), principal component analysis (PCA), multidimensional scaling plots (MDS) and phylogenetic analysis demonstrated that Sichuan Tibetan has a close genetic relationship with Tibet Tibetan, and Sichuan Yi has a genetic affinity with Yunnan Bai group. Furthermore, significant genetic differences have widely existed between Chinese minorities (most prominently for Tibetan and Kazakh) and Han groups, but no population stratifications rather a homogenous group among Han populations distributed in Northern and Southern China are observed. Aforementioned results suggested that these 21 STRs are highly polymorphic and informative in the Sichuan Tibetan and Yi, which are suitable for population genetics and forensic applications.

Genetic polymorphism of 21 non-CODIS STR loci in Chengdu Han population and its interpopulation analysis between 25 populations in China

AGCU 21+1 STR kit contains 21 non-combined DNA index system (non-CODIS) short tandem repeats (STR) loci and a sex-determining locus amelogenin. In this study, we evaluated the genetic diversity and forensically relevant population statistics of 21 non-CODIS loci in 210 Chinese Han individuals from Chengdu city, Sichuan province, Southwest China. No significant deviations from Hardy-Weinberg equilibrium were observed within the 21 non-CODIS STR loci. The combined power of discrimination (CPD) and combined power of exclusion (CPE) were 0.99999999999999999994278, 0.999999355 respectively. To reveal interpopulation differentiations of mainland population of China, a neighbor-joining (N-J) phylogenetic tree was constructed based on Nei's genetic distances among Chengdu Han and 25 published populations. The phylogenetic analyses indicated that Chengdu Han population keeps a close genetic relationship with other Han populations.

Genetic Diversity and Phylogenetic Differentiation of Southwestern Chinese Han: a comprehensive and comparative analysis on 21 non-CODIS STRs

Short tandem repeats (STRs), with high polymorphism and complex evolution information, play a significant role in genetic association studies like population genetics, molecular anthropology and human forensics. However, human genetic diversity has only been partially sampled and available for Southwest Chinese Han population, as well as the genetic architecture of this population remains uncharacterized. In this work, 368 unrelated Han individuals from Sichuan province were firstly genotyped with 21 non-CODIS autosomal STRs, and phylogenetic relationships along administrative (Han Chinese from different regions) and ethnic divisions (minority ethnic groups) were subsequently investigated. The CMP and CPE were 6.2796 × 10-20 and 0.9999999, respectively. Analysis of molecular variance (AMOVA), principal component analysis (PCA), multidimensional scaling plots (MDS) and phylogenetic analysis consistently demonstrated that the Southwest Han population had a close genetic relationship with the geographically close population (Hunan Han) and kept a distant genetic relationship with some ethnic groups, most prominently for Gansu Yugu and Fujian She. Furthermore, no significant genetic distinction between the Northern Han and Southern Han was observed. Aforementioned results suggested that these 21 STRs are highly polymorphic and informative, which are suitable for human identification and population genetics.

Autosomal InDel polymorphisms for population genetic structure and differentiation analysis of Chinese Kazak ethnic group

In the present study, we assessed the genetic diversities of the Chinese Kazak ethnic group on the basis of 30 well-chosen autosomal insertion and deletion loci and explored the genetic relationships between Kazak and 23 reference groups. We detected the level of the expected heterozygosity ranging from 0.3605 at HLD39 locus to 0.5000 at HLD136 locus and the observed heterozygosity ranging from 0.3548 at HLD39 locus to 0.5283 at HLD136 locus. The combined power of discrimination and the combined power of exclusion for all 30 loci in the studied Kazak group were 0.999999999999128 and 0.9945, respectively. The dataset generated in this study indicated the panel of 30 InDels was highly efficient in forensic individual identifcation but may not have enough power in paternity cases. The results of the interpopulation differentiations, PCA plots, phylogenetic trees and STRUCTURE analyses showed a close genetic affiliation between the Kazak and Uigur group.

Genetic diversity and haplotypic structure of Chinese Kazak ethnic group revealed by 19 STRs on the X chromosome

X-chromosomal short tandem repeats (X-STRs) have been widely used in forensic practices involving complicated ties of kinship over the past years, and also play an increasingly important role in population genetics. To study the genetic polymorphisms of 19 STR loci on X chromosome in Chinese Kazak ethnic group, we investigated the allelic and haplotypic frequencies of the 19 loci in 300 (149 males and 151 females) unrelated healthy individuals from Ili Kazak Autonomous Prefecture, Xinjiang Uigur Autonomous Region of China after having evaluated the forensic application value of these loci in forensic sciences, and then compared the population distinctions between the Kazak group and other reference groups. We observed a total of 240 alleles at these X-STR loci with the corresponding allelic frequencies ranging from 0.0017 to 0.5917. In the study, the highest polymorphism was found at DXS10135 locus. The combined power of discrimination in females was 0.999999999999999999999985 and in males 0.999999999999968. The present study indicates that the 19 X-STR loci are very useful for both forensic identification cases and kinship analyses involving a female offspring.

A 30-InDel Assay for Genetic Variation and Population Structure Analysis of Chinese Tujia Group

In the present study, thirty autosomal insertion and deletion polymorphic loci were simultaneously amplified and genotyped in a multiplex system, and their allelic frequencies as well as several forensic parameters were obtained in a sample of 236 unrelated healthy Tujia individuals. All the loci were in Hardy-Weinberg equilibrium after applying a Bonferroni correction and all pair-wise loci showed no significant linkage disequilibrium. These loci were observed to be relatively informative and discriminating, quite efficient for forensic applications. Allelic frequencies of 30 loci were compared between the Tujia group and other reference populations, and the results of analysis of molecular variance indicated the Tujia group showed the least significant differences with the Shanghai Han at one locus, and the most with Central Spanish population at 22 loci. We analyzed the population genetic structure by the principal component analysis, the clustering of STRUCTURE program and a Neighbor-Joining tree, and then evaluated the genetic relationships among Tujia and other 15 populations.

Population genetic analysis of the GlobalFiler STR loci in 748 individuals from the Kazakh population of Xinjiang in northwest China

The six-dye GlobalFiler™ Express PCR amplification kit incorporates 21 commonly used autosomal short tandem repeat (STR) loci and three gender determination loci. In this study, we analyzed the GlobalFiler STR loci on 748 unrelated individuals from a Chinese Kazakh population of Xinjiang, China. No significant deviations from Hardy-Weinberg equilibrium and linkage disequilibrium were observed within and between 21 autosomal STR loci. SE33 showed the greatest power of discrimination in Kazakh population. The combined power of discrimination of Kazakh was 99.999999999999999999999996797 %. No significant differences of allele frequencies were observed between Kazakh and Uyghur at all 15 tested STR loci, as well as Mongolian. Significant differences were only observed between Kazakh and the other Chinese populations at TH01. Multiple STR loci showed significant differences between Kazakh and Arab, as well as South Portuguese. The multidimensional scaling plot (MDS) plot and neighbor-joining tree also showed Kazakh is genetically close to Uyghur.

Genetic variability and phylogenetic analysis of Han population from Guanzhong region of China based on 21 non-CODIS STR loci

In the present study, we presented the population genetic data and their forensic parameters of 21 non-CODIS autosomal STR loci in Chinese Guanzhong Han population. A total of 166 alleles were observed with corresponding allelic frequencies ranging from 0.0018 to 0.5564. No STR locus was observed to deviate from the Hardy-Weinberg equilibrium and linkage disequilibriums after applying Bonferroni correction. The cumulative power of discrimination and probability of exclusion of all the 21 STR loci were 0.99999999999999999993814 and 0.999998184, respectively. The results of genetic distances, phylogenetic trees and principal component analysis revealed that the Guanzhong Han population had a closer relationship with Ningxia Han, Tujia and Bai groups than other populations tested. In summary, these 21 STR loci showed a high level of genetic polymorphisms for the Guanzhong Han population and could be used for forensic applications and the studies of population genetics.

Genetic polymorphism analyses of 30 InDels in Chinese Xibe ethnic group and its population genetic differentiations with other groups

In the present study, we obtained population genetic data and forensic parameters of 30 InDel loci in Chinese Xibe ethnic group from northwestern China and studied the genetic relationships between the studied Xibe group and other reference groups. The observed heterozygosities ranged from 0.1704 at HLD118 locus to 0.5247 at HLD92 locus while the expected heterozygosities ranged from 0.1559 at HLD118 locus to 0.4997 at HLD101 locus. The cumulative power of exclusion and total probability of discrimination power in the studied group were 0.9867 and 0.9999999999902 for the 30 loci, respectively. Analyses of structure, PCA, interpopulation differentiations and phylogenetic tree revealed that the Xibe group had close genetic relationships with South Korean, Beijing Han and Guangdong Han groups. The results indicated that these 30 loci should only be used as a complement for autosomal STRs in paternity cases but could provide an acceptable level of discrimination in forensic identification cases in the studied Xibe group. Further studies should be conducted for better understanding of the Xibe genetic background.

Developmental validation of the AGCU 21+1 STR kit: a novel multiplex assay for forensic application

In this study, we describe the developmental validation assay performed on a novel designed STR multiplex system, AGCU 21+1 STR kit. This kit contains a sex-determining locus amelogenin and 21 noncombined DNA index system STR loci, that are, D6S474, D12ATA63, D22S1045, D10S1248, D1S1677, D11S4463, D1S1627, D3S4529, D2S441, D6S1017, D4S2408, D19S433, D17S1301, D1GATA113, D18S853, D20S482, D14S1434, D9S1122, D2S1776, D10S1435, and D5S2500. The 21+1 kit was validated by a series of tests including optimized PCR conditions, sensitivity, precision and accuracy, stutter ratio, DNA mixture, inhibitors, and species specificity according to the revised validation guidelines issued by the Scientific Working Group on DNA Analysis Methods (SWGDAM). Our results in this study show that the kit is a useful tool for forensic application.

Structural polymorphism analysis of Chinese Mongolian ethnic group revealed by a new STR panel: genetic relationship to other groups

Mongolian is the eighth largest ethnic minority on Chinese population data according to the 2010 census. In the present study, we presented the first report about the allelic frequencies and forensic statistical parameters at the 21 new STRs and analyzed linkage disequilibrium of pairwise loci in the Mongolian ethnic minority, China. Hardy-Weinberg equilibrium tests demonstrated no significant deviations except for the D1S1627 locus. The cumulative power of discrimination and power of exclusion of all the loci are 0.9999999999999999992576 and 0.9999997528, respectively. The results of analysis of molecular variance showed that significant differences between the Mongolian and the other eight populations were found at 1-9 STR loci. In population genetics, the results of principal component analysis, structure analysis, and phylogenetic reconstruction analysis indicated shorter genetic distance between the Mongolian group and the Ningxia Han. All the results suggest that the 21 new STR loci will contribute to Chinese population genetics and forensic caseworks in the Mongolian group.