Forensic characteristics and phylogenetic analyses of the Chinese Yi population via 19 X-chromosomal STR loci

Application of a newly constructed NGS panel with 45 X-linked microhaplotypes demonstrates the unique value of X-MH for kinship testing and mixture analysis

X-linked microhaplotypes (X-MHs) have the potential to be a valuable supplementary tool in complex kinship identification or the resolution of DNA mixtures, because they bring together the distinctive genetic pattern of X chromosomal markers and the benefits of microhaplotypes (MHs). In this study, we used the 1000 Genome database to screen and select 63 X-MHs; 18 MHs were filtered out though a batch sequencing assessment of the DNA samples collected from 112 unrelated Chinese Han individuals. The resulting 45-plex panel performed well in comprehensive assessments including repeatability, sensitivity, species specificity, resistance to PCR inhibitors or degradation, mutation rate, and accuracy in detecting DNA mixture samples. The minimum amount of DNA template that can be tested with this panel is 0.5 ng. Additionally, the alleles of the minor contributor can be accurately detected when the mixture rate is larger than 1:9 in female-male mixture or 1:19 in male-male mixture. Then, we calculated population parameters on each MH based on the allele frequency data obtained from the sequence results of the aforementioned 112 unrelated samples. Combining these parameters on each MH, it can be calculated that TDPm, TDPf, CPET, CPEDFM, CPEDFF and CNCEP3 of the 45-plex system were 1-8.99×10-13, 1-1.62×10-19, 0.9999999995, 0.9999981, 0.9955, 0.9999971 and 0.99940, respectively, indicating that the panel is capable in personal identification and parentage testing. To reveal the unique advantage of X-MHs in the analyses of complex kinship and male DNA mixture, further assessments were made. For complex kinship identification, 22 types of individual pairs with different second-degree kinship were simulated and different types of likelihood ratios (LR) were calculated for each. The results revealed that the panel can achieve accuracy of approximately 70 %∼80 % when dividing each of the three types of second-degree kinships into three or four groups. Theoretically, such sub-division cannot be done by using independent autosomal markers. For male DNA mixture analysis without suspects, the maximum likelihood ratio strategy was derived and employed in the estimation of the number of male contributors (NOMC). Simulations were conducted to verify the efficacy of the 45-plex panel in the field and to compare it with autosomal markers by assuming the 45 MHs as autosomal ones. The results showed that X-MHs can achieve higher accuracy in the estimation of NOMC than autosomal ones when the mixed males were unrelated. The results highlighted the unique value of X-linked MHs in complex kinship and male mixture analyses.

Genetic polymorphism analysis and forensic application evaluation of 57 insertion/deletion polymorphisms from Yi ethnic group in Yunnan

BACKGROUND

As a new kind of diallelic genetic marker, insertion/deletion (InDel) polymorphisms have recently been used in forensic science. However, there are relatively few studies on the forensic evaluation of InDel genetic polymorphisms from different populations.

AIM

The aim of the present work is to assess the genetic polymorphism and forensic applicability of 57 InDels from the Yi ethnic group and explore the genetic background of this group.

SUBJECTS AND METHODS

A total sample of 122 unrelated individuals of Yi group from the Yunnan province were genotyped by the AGCU indel 60 Kit. Multiplex population genetic analyses on the same 57 InDels were carried out among the Yunnan Yi group and 29 reference populations.

RESULTS

The average allele frequency of these loci in the Yi ethnic group was 0.485. Heterozygosity, polymorphism information content, and the power of discrimination were 0.477, 0.362, and 0.612, respectively. The combined power of discrimination and the combined power of exclusion reached to 0.99999999999999999669 and 0.999962965, respectively. The results showed that 57 InDels polymorphisms have high genetic polymorphisms in the Yi ethnic group.

CONCLUSIONS

The 57 InDels could be used for forensic individual identification, paternity testing, and intercontinental population discrimination, with the potential for use in biogeographic ancestry inference.

A forensic population database of autosomal STR and X-STR markers in the Qiang ethnic minority of China

The Qiang ethnic group is one of the oldest ethnic groups in China and is the most active ethnic group among all the populations along the Tibetan-Yi corridor. They have had a profound impact nationally and internationally. The paternal and maternal genetic feature of the Qiang ethnic group has been revealed, leaving the question of the genetic characteristics from autosomes and X chromosome not answered. The aim of this study was to explore the potential of 36 A-STR (Microreader™ 36A ID System) and 19 X-STR (Microreader™ 19X System) for application in the Qiang population and to elucidate their genetic diversity in southwest China. The cumulative probability of exclusion (CPE) for autosomal STRs is 1-1.3814 × 10-15 and the mean paternity exclusion chance (MEC) for X-STRs is 1-1.7323 × 10-6. Forensic parameters suggest that the STRs analyzed here are well-suited for forensic applications. The results of phylogenetic, interpopulation differentiation, and principal coordinates analysis (PCoA) indicate that the Qiang people have extensive connections with ethnic minorities in China, supporting the view that the Qiang people are the oldest group in the entire Sino-Tibetan language family. The Qiang appeared genetically more associated with most ethnic groups in China, especially the Han. The calculation of random matching probability (RMP) was improved by Fst correction of allele frequencies to make RMP more accurate and reasonable. This study can fill in the gaps in the Qiang STR reference database, providing valuable frequency data for forensic applications and evidence for the Qiang's genetic pattern as an important ancestral position in the Sino-Tibetan populations.

Genetic polymorphisms of 19 X-STRs in populations of Hubei Han and Guangxi Zhuang and their comparisons with 13 other Chinese populations

BACKGROUND

A prerequisite for applying short tandem repeat (STR) kits is obtaining population allele and/or haplotype frequencies and forensic parameters.

AIM

Firstly, we aimed to investigate the population data of 19 X-chromosomal STRs (X-STRs) included in the AGCU X19 STR kit in the Han people residing in Hubei Province, Central China, and the Zhuang people residing in the Guangxi Zhuang Autonomous Region of South China. Furthermore, we compared these population data with those for other Chinese populations.

SUBJECTS AND METHODS

In total, 509 unrelated Han males and 266 unrelated Zhuang males were genotyped using the AGCU X19 STR kit. Allele frequencies, haplotype frequencies, and forensic parameters were computed, and genetic differences among 15 Chinese populations were analysed.

RESULTS

The 19 X-STRs showed a high power of discrimination and high mean chance of exclusion, whether calculated using allele or haplotype frequencies. Major differences were found between Han and Oroqen, Uyghur, Mongolian, Tibetan, Li, and Yi populations. Aberrant biallelic patterns at DXS10159, DXS10134, and DXS10079 and allelic dropouts at DXS10164 were observed.

CONCLUSION

The 19 X-STRs were highly polymorphic in the Hubei Han and Guangxi Zhuang populations, and the AGCU X19 STR kit was shown to be suitable for forensic casework.

Genetic polymorphism and forensic application of 23 autosomal STR loci in the Han population of Panjin City, Liaoning Province, Northeastern China

BACKGROUND

Short tandem repeats (STRs) are consecutive repetition of a repeat motif and widely used in forensic medicine and human genetics because of their high polymorphism.

SUBJECTS AND METHODS

In the current study, 23 autosomal STR loci were genotyped from 1263 unrelated healthy individuals living in Panjin City, Liaoning Province, Northeastern China using the VeriFiler^TM Express PCR Amplification Kit. The population comparison was performed between the Panjin Han population and the other relevant groups to further explore the structure of Panjin Han and its relationship with the other groups.

RESULTS

The results found 316 alleles across the 23 STRs and the corresponding allelic frequencies ranged from 0.5198 to 0.0004. Except for D3S1358, TPOX, TH01, and D3S1358, all STR loci were highly polymorphic (PIC > 0.7), with the Penta E locus having the highest degree of polymorphism (0.9147). For population comparison, the exact test of population differentiation found that no significant difference was observed between the Panjin Han and the other Han populations, except for Guangdong Han and Jiangxi Han.

CONCLUSION

The Panjin Han population showed significant differences with the other ethnic groups in China (Bouyei, Dong, Hui, Miao, Tibetan, and Uygur) and the foreign ethnic groups.

X-chromosomal STRs for genetic composition analysis of Guizhou Dong group and its phylogenetic relationships with other reference populations

BACKGROUND

X-chromosomes show a specific genetic mode, which makes genetic markers on the X chromosome play crucial roles in forensic research and human evolution. Dong group, one of 55 minority groups in China, live in Guizhou, Guangxi and Hunan provinces. Even though some genetic data of Y chromosomal short tandem repeats (STRs) and autosomal insertion/deletion polymorphism (InDels) in Dong groups have been reported, there is little research about X-STRs in the Dong group.

AIM

Purposes of this study are to investigate allelic distributions and forensic statistical parameters of 19 X-STRs in the Guizhou Dong group, and explore the genetic composition of the Guizhou Dong group and its phylogenetic relationships with other reference populations.

SUBJECTS AND METHODS

507 Dongs (272 males and 235 females) living in Guizhou province were typed using the AGCU X19 STR kit. Allelic frequencies and forensic parameters of 19 X-STRs in the Guizhou Dong group were calculated. Population genetic analyses of Guizhou Dong and other 17 reference populations were conducted using D_A genetic distances, phylogenetic tree, principal component analysis and multidimensional scaling.

RESULTS

A total of 230 alleles of 19 X-STRs were identified in all Dongs. The frequencies of 19 loci ranged from 0.0013 to 0.6838. Cumulative power of discrimination in males (PDM), Cumulative power of discrimination in females (PDF), four different kinds of mean exclusion chance (MEC_Kruger, MEC_Kishida, MEC_Desmarais and MEC_Desmarais_du) values of 19 X-STRs in all individuals were 0.999999999999761, 0.9999999999999999999993951, 0.999999964841617, 0.999999999997261, 0.999999999997297 and 0.999999993623172, respectively. Besides, genetic polymorphisms of seven linkage clusters ranged from 0.9381 to 0.9963. In addition, these seven groups showed high polymorphism information content (PIC), PDM, PDF, MEC_Kruger, MEC_Kishida, MEC_Desmarais and MEC_Desmarais_duo values. Population genetic analyses of Guizhou Dong and other 17 reference populations showed that the Guizhou Dong group had close genetic relationships with surrounding Tai-Kadai-speaking, Hmong-Mien-speaking and Han groups.

CONCLUSION

Nineteen X-STRs displayed high genetic diversities and could be employed for forensic personal identification and paternity analysis in the Guizhou Dong group. Close genetic affinities between Guizhou Dong and surrounding populations were observed based on the 19 X-STRs in 17 reference populations.

Genetic polymorphisms of 16 X-STR loci analyzed in the Han population of Yunnan Province, Southwest China

To investigate the genetic diversity and forensic identification efficiency of X-chromosomal short tandem repeats (X-STRs) in the Yunnan Han population, 16 X-STRs in 415 Yunnan Han individuals (247 males and 168 females) were studied. A total of 137 alleles were detected, and all loci in the Yunnan Han population were highly polymorphic. The combined discrimination of males (PDm) and females (PDf) was 0.9999997769115 and 0.999999999999999999996, respectively. Interpopulation comparisons between the Yunnan Han population and 21 other populations showed that the evolutionary relationships between different groups with the same ethnic group or nearby geographic origins were closer. This study provides the first data on X-STR genetic polymorphisms in the Yunnan Han population and enriches the X-STR database for the Chinese Han population.

Forensic genetic polymorphisms of 16 X-STR loci in the Yunnan Miao population and their relationship to other Chinese groups

Allele frequencies for 16 X-chromosomal STR (X-STR) loci were obtained from a sample set of 440 unrelated Yunnan Miao individuals in China. A total of 117 alleles were observed in this group, with allele frequencies ranging from 0.0016 to 0.7565. The most informative marker for the studied population was DXS10134, with a polymorphism information content (PIC) of 0.8499, and the least polymorphic locus was DXS6810 (PIC = 0.3071). The power of discrimination (PD) varied from 0.4046 (DXS6800) to 0.8642 (DXS10134) in males and from 0.6188 (DXS6800) to 0.9673 (DXS10134) in females. The combined PDM and PDF were 0.999999989975990 and 0.999999999999949, respectively. The combined MECD and MECT were 0.999983301904059 and 0.999999915883733, respectively. Furthermore, population genetic structure investigation between the Yunnan Miao and 20 other populations using principal component analysis (PCA), multidimensional scaling plot (MDS), and neighboring-joining (NJ) phylogenetic tree analyses illustrated significant genetic difference between the Yunnan Miao and the other populations. This study is the first to provide X chromosome genetic polymorphism data of the Miao population in Yunnan Province and can be used as a supplementary reference to enrich the national database.

Genetic polymorphism of 19 autosomal STR loci in the Yi ethnic minority of Liangshan Yi autonomous prefecture from Sichuan province in China

The Yi is one of fifty-six ethnic populations and one of the most ancient ethnic groups in China. The Liangshan Yi Autonomous Prefecture (LYAP) in Sichuan Province has the single largest Yi community in China. To establish a Yi population database in the LYAP of Sichuan in China, a Goldeneye™ DNA Identification System 20A Kit with 19 autosomal STRs (short tandem repeats) was used. As a result, the total discrimination power (TDP) and the cumulative probability of exclusion (CPE) for these STRs in 1016 unrelated individuals were 0.999999999999999999999897 and 0.9999999597, respectively. Totals of 273 alleles for 19 STRs and 8-22 alleles for each locus were found. The allelic frequencies ranged from 0.0005 to 0.5084. The forensic parameter averages of these STRs were as follows: observed heterozygosity (H_obs) of 78.44%, expected heterozygosity (H_exp) of 79.89%, discrimination power (DP) of 92.66%, and probability of exclusion (PE) of 57.68%. Penta E presented the highest levels of H_obs and DP, whereas TPOX showed the lowest H_obs and DP values. Nei's standard genetic distance matrix among 31 populations found that the nearest genetic distance to the Yi population was the Sichuan Han (0.0056). Altogether, we first reported the forensic parameters and allele frequencies of 19 autosomal STRs of the Yi group in Liangshan. These 19 STR makers could provide highly informative polymorphisms for individual identification, paternity testing and genetic population analyses.

Genetic diversity, forensic feature, and phylogenetic analysis of Guizhou Tujia population via 19 X-STRs

BACKGROUND

X-chromosome short tandem repeats (X-STRs) with unique sex-linkage inheritance models play a complementary role in forensic science. Guizhou is a multiethnic province located in southwest China and some genetic evidence focusing on X-STRs for various minorities was reported. However, population data of Guizhou Tujia are scarce.

METHODS

A total of 507 Guizhou Tujia individuals were profiled using the AGCU X-19 STR kit. Allele frequencies and forensic parameters were calculated. Additionally, population genetic relationships between Guizhou Tujia and other 19 populations were explored.

RESULTS

A total of 257 alleles with the allele frequencies ranged from 0.0013 to 0.6098 were found. The combined power of discrimination in males and females and mean exclusion chances in all case scenarios were all greater than 0.99999. Population comparisons showed Guizhou Tujia had a homogeneity with all Han populations from different administrative regions, and other ethnic populations residing in Guizhou, while had obviously genetic heterogeneity with the Altaic family populations except Xibe.

CONCLUSION

Nineteen X-STRs can afford a reliable and informative database of Guizhou Tujia population for human identification and paternity testing, especially in complex biological relations. The genetic relationships of Chinese are significantly influenced by the geographic position and ethnolinguistic origin.

Population genetics, diversity, forensic characteristics of four Chinese populations inferred from X-chromosomal short tandem repeats

We genotyped 19 X-STRs included in the AGCU X19 kit in 712 unrelated Chinese individuals from four populations (Li, Hui, Tibetan, and Han) and then merged with 4156 previously genotyped subjects from 19 populations to investigate genetic relationships and population structure, as well as the association between the genetic affinity and language classification. The combined mean paternity exclusion chances and the combined probabilities of discrimination based on single allele frequencies of 19-X-STRs and haplotype frequencies of seven linkage groups were high, indicating that this set of markers was very polymorphic in the four populations studied. Therefore, this panel can complement autosomal or uniparental markers in kinship analysis and complex deficient paternity testing. Subsequently, population differentiation analyses among 23 populations based on 19 STRs and 15 populations based on over 62 million single nucleotide polymorphisms consistently demonstrated that genetic stratifications exist between the different language-speaking populations, especially Tibeto-Burman-speaking, Tungusic and Turkic-speaking populations. Our newly studied populations are genetically close to ethnolinguistically adjacent populations. Our datasets can and should be used as an allele and haplotype frequencies reference database to facilitate the use of 19-X-STRs panel in routine forensic practice.

Forensic genetic polymorphisms and population structure of the Guizhou Bouyei people based on 19 X-STR loci

Background: Guizhou province is located in southwest China with abundant genetic, linguistic and cultural diversity. The Bouyei is one of the 18 officially recognised minority groups in Guizhou, accounting for about 97% of the total Bouyei population in China. However, the genetic history and forensic characterisation of the Bouyei people is largely unknown due to a lack of genetic data.Aim: We aim to investigate genetic polymorphisms and forensic characterisation of the Guizhou Bouyei population, as well as the relationships between the Bouyei and other East Asian populations.Subjects and methods: We genotyped 19 X-STRs in 188 males and 165 females of Guizhou Bouyei using the AGCU X19 STR Kit. We estimated allele frequencies, forensic parameters and genetic distances between the Bouyei and other East Asian populations. We presented the genetic distances in a phylogenetic tree, an MDS plot and a PCA plot.Results: In Guizhou Bouyei individuals, we observed 216 alleles with corresponding frequencies ranging from 0.0019 to 0.6757. All of the six combined powers of PD_m, PD_f, MEC Krüger, MEC Kishida, MEC Desmarais and MEC Desmarais in allele diversity and haplotype diversity are larger than 0.99999995. We found genetic affinities among the Bouyei people and their geographical neighbouring populations in Guizhou, such as the Sui, Miao and Han.Conclusions: The highly polymorphic and informative forensic parameters of the 19 X-STRs in Bouyei people show the powerful potential of those markers in forensic identification and parentage tests. The genetic relationships of the Bouyei with other East Asian populations correspond well with geographic affiliations as well as linguistic classifications.

Genetic structure and forensic characterisation of 19 X-chromosomal STR loci in Guizhou Sui population

Background: Guizhou Sui people are an officially recognised ethnic group living in southwest China, but have seldom been studied genetically.Aim: To investigate the polymorphisms of 19 X-chromosome STR loci in a typical Sui population and enrich the East Asian X-STR reference database for forensic DNA analysis.Subjects and methods: A total of 400 Sui individuals (195 males and 205 females) were genotyped at 19 X-STR loci using the AGCU X19 STR Kit. The allele frequencies and forensic parameters were calculated and illustrated and the data of Guizhou Sui were merged with 18 other nationwide populations to explore genetic polymorphisms and population relationships.Results: A total of 215 alleles were observed with corresponding frequencies ranging from 0.0017-0.6512 in Sui using male and female pooled allele frequencies. Large values were observed, at least 0.9999999933, in combined powers of discrimination of Sui males and females, as well as the four mean paternity exclusion chances (MECs). The phylogenetic analysis among 19 populations showed that Sui have close genetic affinities with other Tai-Kadai populations, as well as the Sinitic populations living in southern China.Conclusions: The AGCU X-19 STRs are highly polymorphic and informative in Guizhou Sui people. The genetic relationships between Sui and other populations in China are generally consistent with the language classification and geographical distance.

Tai-Kadai-speaking Gelao population: Forensic features, genetic diversity and population structure

Genetic analyses of geographically and ethno-linguistically different populations are essential for understanding population stratification and genomic structure in medical Genome-Wide Association Studies (GWAS) and genetic variation and diversity related to forensic and population genetics studies. Here, we genotyped 30 autosomal insertion/deletion (Indel) markers from 502 Tai-Kadai-speaking Gelao individuals residing in the rugged topographical area in Southeastern China. In addition, two comprehensive population genetic comparisons of 15,327 individuals from 95 worldwide populations and of 6122 individuals from Asia and adjoining populations were conducted based on allele frequency data and raw genotype data, respectively. All studied markers were found to be in Hardy-Weinberg equilibrium. The combined power of discrimination in the Gelao minority group was 0.999999999975, and the combined probability of exclusion was 0.9879. Our results from the forensic statistical parameters indicated that this Indel panel can be independently used as a powerful tool in forensic individual identification but can only be used as a complementary tool in paternity cases involving East Asians. We also found significant allele frequency differences between the Gelao and other continental populations with respect to the markers grouped in clusters ∼Ⅳ, suggesting that these can be used as forensic ancestry informative Indel markers to distinguish the Gelao from other continental populations. Genetic ancestry analyses demonstrated that Tai-Kadai-speaking Gelao share a dominant ancestry component with Hmong-Mien-speaking Miao. Our population genetic results from multidimensional scaling plots, principal component analysis, neighboring-joining tree construction and hierarchical clustering also suggested that the Zunyi Gelao are genetically closer to their linguistically or geographically close populations, such as the Han Chinese, Guizhou Bouyei and the Hubei Tujia, than to Turkic and Tibeto-Burman speakers.

Forensic and phylogenetic analyses among three Yi populations in Southwest China with 27 Y chromosomal STR loci

We have analyzed the Y chromosome haplotypes of 510 non-related Yi males grouped in three Chinese provinces (Guizhou, Sichuan, and Yunnan) using the Yfiler® Plus Kit. A total of 484 haplotypes were detected, out of which 460 were unique. The observed haplotype diversity and discrimination capacity were 0.9998 and 0.9490, respectively. To investigate the genetic relationship of the studied population, multidimensional scaling (MDS) plot and neighbor-joining (NJ) tree phylogenetic analyses were constructed which demonstrated that the Y chromosome lineage among the Yi ethnicity was different.

Population Genetic Diversity and Phylogenetic Characteristics for High-Altitude Adaptive Kham Tibetan Revealed by DNATyperTM 19 Amplification System

Tibetans residing in the high-altitude inhospitable environment have undergone significant natural selection of their genetic architecture. Recently, highly mutational autosomal short tandem repeats were widely used not only in the anthropology and population genetics to investigate the genetic structure and relationships, but also in the medical genetics to explore the pathogenesis of multiple genetic diseases and in the forensic science to identify individual and parentage relatedness. However, genetic variants and forensic efficiency of DNATyper^TM 19 amplification system and genetic background of Kham Tibetan remain uncharacterized. Thus, we genotyped 19 forensic genetic markers in 11,402 Kham Tibetans to gain insight into the genetic diversity of Chinese high-altitude adaptive population. Highly discriminating and polymorphic forensic measures were observed, which indicated that this new-developed DNATyper 19 PCR amplification is suitable for routine forensic identification purposes and Chinese national DNA database establishment. Pairwise genetic distances among the comprehensive population comparisons suggested that this high-altitude adaptive Kham Tibetan has genetically closer relationships with lowlanders of Tibeto-Burman-speaking populations (Chengdu Tibetan, Liangshan Tibetan, and Liangshan Yi). Genetic substructure analyses via phylogenetic reconstruction, principal component analysis, and multidimensional scaling analysis in both nationwide and worldwide contexts suggested that the genetic proximity exists along the linguistic, ethnic, and continental geographical boundary. Further studies with whole-genome sequencing of modern or archaic Kham Tibetans would be useful in reconstructing the Tibetan population history.

Genetic diversities and phylogenetic analyses of three Chinese main ethnic groups in southwest China: A Y-Chromosomal STR study

Short tandem repeats (STRs) located on the Y chromosome with the properties of male-specific inheritance and haploidy are widely used in forensics to analyze paternal genealogies and match male trace donors to evidence. Besides, Y-chromosomal haplotypes play an important role in providing breathtaking insights into population genetic history. However, the genetic diversity and forensic characteristics of Y-STRs in Guizhou main ethnic groups (Hans, Miaos and Bouyeis) remain uncharacterized. Here, we obtained Y-chromosomal 23-marker haplotypes in three Guizhou populations and submitted the first batch of Y-STR haplotype data to the YHRD. The HD in the aforementioned three populations are 0.99990, 0.99983, and 0.99979, respectively, and DC values are 0.9902, 0.9908, and 0.97959, respectively. Subsequently, genetic differentiation between our newly studied populations and reference groups along ethnic/administrative divisions, as well as national/continental boundaries were investigated via AMOVA, MDS, and phylogenetic relationship reconstruction. Significant genetic differentiations from our subjects and other groups are identified in ethnically, linguistically and geographically diverse populations, including most prominently Tibetans and Uyghurs among 30 mainland Chinese populations, Taiwanese groups and others among 58 Asian populations, as well as African groups and others among 89 worldwide populations. Qiannan Bouyei has a close genetic relationship with Guangxi Zhuang, and Zunyi Han and Qiandongnan Miao have close genetic affinity with Hunan Han and Guizhou Shui, respectively. Collectively, this new-generation Y-STR amplification system can be used as a supplementary tool in forensic identification and male parentage testing and even pedigree search.

Genetic structure and polymorphisms of Gelao ethnicity residing in southwest china revealed by X-chromosomal genetic markers

X-chromosome short tandem repeat markers (X-STRs), due to their special inheritance models, physical location on a single chromosome and the absence of recombination in male meiosis, play an important role in forensic and population genetics. While a series of genetic analyses focusing on the genetic diversity and forensic characteristics of X-STRs are well studied for ethnically/linguistically diverse and demographically large Chinese populations, genetic evidence from Gelao ethnicity is still sparse. Here, we genotyped the first batch of 19 X-STRs in 513 Chinese Gelao individuals (265 females and 248 males), and reported genetic polymorphisms, forensic characteristics based on the single locus and seven linkage groups. DXS10135 with the highest PIC (0.9106) and LG1 (DXS10148-DXS10135-DXS8378) with the largest HD (0.9970) are polymorphic and informative. The CPDs in Gelao males and females are respectively larger than 0.999999999997095 and 0.99999999999999999999918, and the combined MECs are larger than 0.999999975715109. Subsequently, we investigated the population relationships among 14 Chinese populations based on 19 X-STRs and among 23 populations based on 11 overlapped X-STRs. Our results revealed genetic differentiations among Tibeto-Burman, Altaic and other Chinese homogenous populations, and demonstrated that Guizhou Gelao has the genetically closer relationships with Han Chinese and geographically close Guizhou Miao.

Forensic characterization and genetic polymorphisms of 19 X-chromosomal STRs in 1344 Han Chinese individuals and comprehensive population relationship analyses among 20 Chinese groups

X-chromosomal short tandem repeats (X-STRs) may assist resolution of complex forensic kinship cases and complement autosomal and Y-chromosomal STRs in routine forensic practice and population genetics. In the present study, we investigated the allele/haplotype diversity and forensic genetic characteristics of 19 X- STRs in 206 Guizhou Han and 1344 Meta-Han Chinese individuals using AGCU X19 PCR amplification system. Population relationships within five Han Chinese population groups (1344 individuals), between Guizhou Han and other 19 Chinese reference populations belonging to four language families (5074 individuals), as well as between Meta-Han Chinese and other 15 minorities (3730 individuals) were performed using Reynolds’s, Nei’s and Fst genetic distances, principal component analysis (PCA), multidimensional scaling (MDS), Structure and Neighbor-Joining tree. Mean paternity exclusion chance (MEC) in Duos > 0.99999999453588 and in trios > 0.99999999999781, as well as power of discrimination (PD) > 0.99999999999980 in Guizhou Han on the basis of allele frequencies. Consistent high MECs and PDs can be observed in Meta-Han Chinese population based on both allele diversities of 19 markers and haplotype diversities of seven linkage groups (LG). DXS10135 and LG1 are the most informative and polymorphic in Han Chinese group. The comprehensive population comparisons reveal that Han Chinese is a homogenous population and has the genetically closer relationship with Hmong-Mien-speaking groups than Tibetan-Burman-speaking and Turkic-speaking populations. In summary, AGCU X19 PCR amplification system is highly polymorphic and informative in Guizhou Han and Han Chinese populations. The comprehensive population data from 20 Chinese populations analyzed in this study may be used as a reference Chinese frequency database of X-STRs for forensic casework applications.

Allele frequencies of 15 autosomal STRs in Chinese Nakhi and Yi populations

Genetic characterization of ethnically and geographically diverse populations via short tandem repeats (STRs) is relevant to various fundamental and applied areas of forensic genetics, population studies, and even molecular anthropology. In the present study, genetic polymorphisms of 15 autosomal STR loci were firstly obtained from 918 individuals (495 Nakhis and 423 Yis) residing in the foothills of the Himalayas. The cumulative powers of discrimination and probabilities of exclusion in the two studied ethnic groups were both larger than 0.999999999999999982 and 0.9999961, respectively. Genetic similarities and differences among 61 populations were subsequently investigated by pairwise Cavalli-Sforza genetic distance, multidimensional scaling plots, principal component analysis, and phylogenetic relationship reconstruction. Both Nakhi and Yi had the genetically close relationships with Yunnan Bai and distinct relationships with Xinjiang Turkic-speaking populations (Uyghur and Kazakh) and Vietnamese.

Genetic diversity and haplotype analysis of Guizhou Miao identified with 19 X-chromosomal short tandem repeats

We analyzed Chinese Miao population samples (n = 268) from Guizhou province, Southwest China, with 19 X-chromosomal short tandem repeats (STRs) included in the AGCU X19 amplification kit. The combined PE is 0.999999922 and the combined PDs in males and females are 0.9999999999999999999994 and 0.9999999999998, respectively. The mean paternity exclusion change values are larger than 0.99999996. The HDs in seven linkage groups vary from 0.9324 to 0.9968. Subsequently, comparison among different Chinese populations shows that the substructures of Chinese were significantly influenced by ethno-linguistic rather than geographical boundaries, including most prominently Turkic-speaking and Tibeto-Burman-speaking populations.

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.

Massively parallel sequencing of 165 ancestry informative SNPs in two Chinese Tibetan-Burmese minority ethnicities

The Tibeto-Burman language, one subfamily of the Sino-Tibetan languages, is spoken by over 60 million people all over East Asia. Yet the ethnic origin and genetic architecture of Tibeto-Burman speaking populations remain largely unexplored. In the present study, 169 Chinese individuals from Tibeto-Burman speaking populations (two ethnic groups: Tibetan and Yi) in four different geographic regions in western China were analyzed using the Precision ID Ancestry Panel (165 AISNPs) and the Ion PGM System. The performance and corresponding forensic statistical parameters of this AISNPs panel were investigated. Comprehensive population genetic comparisons (143 populations based on Kidd' SNPs, 92 populations on the basis of Seldin' SNPs and 31 populations based on the Precision ID Ancestry Panel) and ancestry inference were further performed. Sequencing performance demonstrated that the Precision ID Ancestry Panel is effective and robust. Forensic characteristics suggested that this panel not only can be used for ancestry estimation of Tibeto-Burman populations but also for individual identification. Tibetan and Yi shared a common genetic ancestry origin but experienced the complex history of gene flow, local adaptation, and isolation, and constructed the specific genetic landscape of human genetic diversity of Highlander and Lowlander populations. Tibetan-Burman populations and other East Asian populations showed sufficient genetic difference and could be distinguished into three distinct groups. Furthermore, analysis of population structure revealed that significant genetic difference was existed inter-continent populations and strong genetic affinity was observed within-continent populations. Additional population-specific AISNPs and a relatively more comprehensive database with sufficient reference population data remain necessary to get better-scale resolution within a geographically proximate populations in East Asia.

Genetic characteristics and phylogenetic analysis of three Chinese ethnic groups using the Huaxia Platinum System

Short tandem repeats (STRs) are attractive to genetic applications like forensic, anthropological and population genetics studies. The Huaxia Platinum System was specifically developed to allow co-amplification and detection of all markers in the expanded CODIS core loci and the Chinese National Database. In this study, in continuation to our previous validation study, 568 unrelated individuals were firstly genotyped to investigate the effectiveness of this novel assay in 3 main ethnic groups of China (Han, Tibetan and Yi). The combined power of discrimination (CPD) were 0.9999999999999999999999999992, 0.999999999999999999999999992, 0.999999999999999999999999998, respectively, and the combined power of exclusion (CPE) were 0.9999999999, 0.999999995, 0.999999998, respectively. Next, genetic relationships along administrative and ethnic divisions were analyzed using pairwise genetic distances, multidimensional scaling (MDS), principal component analysis (PCA) and phylogenetic analysis. The Han ethnicity showed a high genetic homogeneity all across China, and significant genetic differences existed between Han groups and some minority groups, most prominently for the Tibetans, the Uyghurs, the Kazakhs, the Miaos, the Zhuangs and the Dais. Aforementioned results suggested that the Huaxia Platinum System is polymorphic and informative, which provides an efficient tool not only for human forensics, but also for population genetics studies.

Genetic variation and forensic characterization of highland Tibetan ethnicity reveled by autosomal STR markers

Understanding the origin and genetic background of Chinese high-altitude Tibetans play a pivotal role in medical genetics, archeology, anthropology, and forensics. In this study, to investigate the forensic characterization and genetic diversity of Chinese Tibetan, allele frequencies and corresponding forensic statistical parameters of 15 autosomal STRs included in the AmpFℓSTR® Sinofiler™ kit were obtained from 1220 Tibetan individuals residing in Lhasa country, Tibet Autonomous Region. We identified 191 alleles with corresponding allele frequencies varied from 0.0004 to 0.3984. The combined probability of discrimination and the combined probability of exclusion are 0.9999999999999999997 and 0.9999996, respectively. Our study provided the valuable dataset for forensic individual identification and parentage testing in the high-altitude Tibetan population. In addition, comprehensive population comparisons among 30 Chinese populations via PCA, AMOVA, MDS, and N-J tree demonstrated that the genetic components of Tibet Tibetan have received gene introgression from surrounding lowland populations (Such as Gansu Hui and Yunnan Bai) and Tibetan keeps the close genetic relationship with geographic neighboring 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.

X-chromosomal STR-based genetic structure of Sichuan Tibetan minority ethnicity group and its relationships to various groups

The X-chromosomal short tandem repeats (STRs) with more informative than autosomal STRs in some complicated biological relationships identification due to its specific mode of genetic transmission can be used as a complementary tool in forensic case practices. In this study, we presented the population genetic data of 19 X-STRs, consisting of DXS10174, DXS10075, DXS10079, DXS101, DXS10101, DXS10103, DXS10134, DXS10135, DXS10148, DXS10159, DXS10162, DXS10164, DXS6789, DXS6809, DXS7132, DXS7423, DXS7424, DXS8378, and HPRTB loci, in a sample of 235 individuals of Tibetan nationality from Sichuan province, Southwest China. All 19 X-STR loci were consistent with Hardy-Weinberg equilibrium. The results showed that the combined power of discrimination in females and males are 0.999999999999999999997 and 0.9999999999997, respectively. In addition, the mean paternity exclusion chances based on the formula of MEC_Krüger, MEC_Kishida, and MEC_Desmarais as well as MEC_{Desmarais Duo} are 0.99999991, 0.9999999999924, 0.9999999999929, and 0.999999985, respectively. In summary, our findings suggested that the AGCU X19 kit can be considered to serve as a high polymorphic information tool for forensic identification and kinship testing in the Sichuan Tibetan population. Furthermore, population genetic structure investigation between Sichuan Tibetan population and other 19 populations using PCA, MDS, and phylogenetic tree illustrated that significant genetic difference was observed between the Sichuan Tibetan and Malay, as well as the Xinjiang Uyghur population.

Population data and forensic efficiency of 21 autosomal STR loci included in AGCU EX22 amplification system in the Wanzhou Han population

Autosomal short tandem repeats (STRs), widely distributed in the whole human genome, play an important role in personal identification and parentage testing. In this study, the allele frequencies and forensic efficiency parameters of 21 autosomal STR loci included in the AGCU EX22 kit were obtained from 433 Chinese Han individuals residing in the Wanzhou District in the north of Chongqing Municipality, Southwest China. No deviation from Hardy-Weinberg equilibrium was observed in all of the 21 STR loci. A total of 241 alleles were observed with allele frequencies ranging from 0.0011 to 0.5418. The cumulative power of discrimination and the cumulative probability of exclusion were 0.9999999999999999999999999 and 0.999999996, respectively. The results of genetic distance, neighbor-joining tree, principal component plots, and multidimensional scaling analysis revealed that the Wanzhou Han had more genetic differences when compared with Kazakh and Uyghur populations from Xinjiang than other included reference populations. In summary, the results in forensic characteristic analyses indicated that the 21 STRs are highly polymorphic and can be served as a useful tool in forensic routine practices. The population comparison indicated that close geographic or ethnic origin groups had a strong genetic affinity with each other.

Genetic diversity of 21 autosomal STR loci in the Han population from Sichuan province, Southwest China

Exploration of the ethnic origin and genetic differentiation of 56 Chinese officially recognized nationalities populations played a fundamental role in the research field of population genetics, forensic science, linguistics, anthropology, and archaeology. In the present study, population data of 21 autosomal STR loci (CSF1PO, D10S1248, D12S391, D13S317, D16S539, D18S51, D19S433, D21S11, D2S1338, D2S441, D3S1358, D5S818, D6S1043, D7S820, D8S1179, FGA, Penta D, Penta E, TH01, TPOX, and vWA) included in the AGCU EX22 kit in 2793 Southwest Han Chinese individuals was obtained and population genetic relationships among 28 Chinese populations were investigated. Our study indicated that the twenty-one autosomal STRs are highly polymorphic in the Sichuan Han population and can be used as a powerful tool in the routine forensic usage. MDS and phylogenetic analysis suggested that the Sichuan Han population kept a close genetic relationship with the southwest populations.