Combined Power Of Discrimination Research Articles

Population genetics and forensic efficiency of 30 InDel markers in four Chinese ethnic groups residing in Sichuan

Sichuan Province is located at the transitional junction regions of the Qinghai-Tibet Plateau and the low-altitude plains. It also serves as the corridor of Sino-Tibetan-speaking population migration and expansion since neolithic expansion of Proto-Tibeto-Burman populations from Middle/Upper Yellow River during Majiayao period (3300–2000 BC). However, the population structure and the corresponding genetic diversity of forensic-related markers in this region remain unclear. Thus, we genotyped 30 insertion-deletion (InDel) markers in 444 samples from four ethnic groups (Han, Tibetan, Hui and Yi) from Sichuan Province using the Investigator® DIPplex kit to explore the characteristics of population genetics and forensic genetic focuses. All the loci were found to be in Hardy-Weinberg Equilibrium (HWE) after applying a Bonferroni correction and no pairwise loci showed prominent linkage disequilibrium. The combined matching probability (CMP) and the combined power of discrimination (CPD) are larger than 1.8089 × 10−11 and 0.99999999995, respectively. Principal component analysis, multi-dimensional scaling plots and Neighbour-Joining tree among 65 worldwide populations indicated that Sichuan Hui and Han are genetically close to Hmong-Mien and Tai-Kadai-speaking populations, and Sichuan Tibetan and Yi bear a strong genetic affinity with Tibeto-Burman-speaking populations. The model-based genetic structure further supports the genetic affinity between the studied populations and linguistically close populations. Key Points Forensic parameters of 30 insertion-deletions (InDels) in 444 individuals from four populations are reported, which showed abundant genetic affinity and diversity among populations and high value in personal identification. Genetic similarities existed between the studied populations and ethnically, linguistically close populations. Sichuan Hui and Han are genetically close to Hmong-Mien and Tai-Kadai-speaking populations. Sichuan Tibetan and Yi bear a strong genetic affinity with Tibeto-Burman-speaking populations.

Close genetic relationship between central Thai and Mon people in Thailand revealed by autosomal microsatellites.

Central Thailand is home to diverse populations with the central Thai constituting the major group, while the Mon, who migrated from southern Myanmar, are sparsely distributed within the region. A total of 338 individuals of eight central Thai (246 samples) and three Mon populations (92 samples) were newly genotyped. When combined with our previously published Mon data, this provides a total of 139 Mon samples. We found genetic similarity between the central Thai and Mon and weak sub-structuring among Thais from central, northern, and northeastern Thailand. The forensic parameter results show high discrimination values which are appropriate for forensic personal identification and paternity testing in both the central Thai and Mon; the probabilities of excluding paternity are 0.999999112 and 0.999999031, respectively, and the combined discrimination power is 0.9999999999999999999999 in both groups. This regional allelic frequency on forensic microsatellites may serve as a useful reference for further forensic investigations in both Thailand and Myanmar.

Genetic polymorphism analysis of 23 STR loci in the Tujia population from Chongqing, Southwest China.

To evaluate the applicability of 23 autosomal STR loci (D10S1248, D11S4463, D12ATA63, D14S1434, D17S1301, D18S853, D1GATA113, D1S1627, D6S1017, D20S1082, D20S482, D17S974, D22S1045, D1S1677, D2S1776, D2S441, D3S4529, D4S2408, D9S1122D5S2500, D6S474, D18S51, D9S2157) included in DNA Typer™ 25 Kit for individual identification and parentage testing, allele frequencies and forensic efficiency parameters were first obtained from healthy, unrelated 506 Chongqing Tujia individuals. A total of 1012 alleles were identified in 23 STR loci, and allele frequencies ranged from 0.001 to 0.5761. The combined power of discrimination (CPD) and the combined power of exclusion (CPE) of the 23 STR loci were 0.999999999999999999999753 and 0.99999967, respectively. These results suggested that 23 autosomal STR loci could be used as an effective tool for forensic application in Chongqing Tujia population. Comprehensive comparisons were conducted based on the analysis of genetic distance, principal component analysis (PCA), multidimensional scaling plot (MDS), and phylogenetic tree to explore the interpopulation genetic relationship. Our results revealed that Chongqing Tujia keeps the more relatively genetic similarity with Hunan Han, Hubei Tujia, and Sichuan Han, which could be interpreted by that those populations were originated from the same ethnic ancestor or genetic communication were happened in adjacent areas.

Allelic frequency database of 15 polymorphic autosomal STRs in the Malayalam-speaking population of Kerala, India.

In this study, we assessed and established an allelic frequency database of Malayalam-speaking population of south western Indian state Kerala, using 15 polymorphic short tandem repeats (STRs) genetic markers. For this study, 464 unrelated healthy individuals were randomly selected following the ethical standards. The most polymorphic and most discriminating locus was D2S1338, with a value of 0.860 and 0.968, respectively. The range of heterozygosity extended from a minimum of 0.668 (TH01) to a maximum of 0.847 (D2S1338). The combined discrimination power (CPD) and combined exclusion power (CPE) were 1 and 0.999997861, respectively, for all 15 autosomal STR loci under study. The combined probability of match (CPM) and combined paternity index (CPI) for all 15 autosomal STR loci were found to be 9.85 × 10-19 and 4.18 × 105, respectively.

Genetic structure and forensic characteristics of the Kyrgyz population from Kizilsu Kirghiz autonomous prefecture based on autosomal DIPs.

Living in the heart of Eurasia, the Kyrgyz ethnic minority have a complex human evolutionary and migration history. However, the genetic architecture of the Kyrgyz population has not been fully explored. We studied 526 Kyrgyz samples from Kizilsu Kirghiz Autonomous Prefecture in Xinjiang using the Investigator® DIPplex kit. All loci followed Hardy-Weinberg equilibrium (HWE). The combined power of discrimination (CPD) and combined power of paternity exclusion (CPE) was 0.9999999999988 and 0.9936, respectively. Compared with 90 reference populations, five InDels (HLD99, HLD81, HLD64, HLD118, and HLD111) have the potential to distinguish the Kyrgyz/Uyghur/Kazak population from other East Asian populations. Our results suggested a close genetic relationship between the Kyrgyz population and the Uyghur/Kazak populations, followed by South Asian populations. This was in accordance with the inland migration hypothesis or modern human migration influenced by warfare. Overall, this system can be used as a powerful tool in forensic individual identification and as a complementary tool in paternity cases and biogeographic ancestry analyses.

Genomic portrait of Odisha, India drawn by using 21 autosomal STR markers.

In order to find out the genetic diversity in the eastern Indian population of Odisha consisting of various linguistic and ethnic groups, we undertook a study on 508 unrelated healthy individuals belonging to Odisha, India. We assessed genetic variation and compared the data with published literature of Indian population consisting of different ethnic groups from different geographical areas using 21 autosomal STR markers. The most polymorphic and discriminatory STR locus in the studied population was found to be SE33 with the calculated values of 0.94 and 0.991 respectively for both the parameters. The combined power of discrimination (CPD) and combined power of exclusion (CPE) were found to be 1 and 0.999999999704865 respectively. The combined probability of match (CPm) and combined paternity index (CPI) for all 21 autosomal STR loci were found to be 8.01 × 10-26 and 3.45 × 109 respectively. Though, the studied eastern Indian population of Odisha shared its closest genetic affinity with nearest Indian geographical regions, i.e., the population of Jharkhand which is geographically located in eastern India as well as the Central Indian population.

Genetic variation and population structure analysis of Chinese Wuzhong Hui population using 30 Indels

Background: Insertions and deletions (Indels) have been used in routine forensic studies, archaeology, and population genetics. They have certain advantages, such as absence of stutter, small amplicon lengths, and low mutation rates. The genetic variations and forensic features of Indels in the Wuzhong Hui population are, as yet, unclear.Aim: To investigate the genetic polymorphisms of 30 Indels in Wuzhong Hui people and explore their genetic relationship with 48 reference populations from all over the world.Subjects and methods: We genotyped 30 Indels included in the Investigator DIPplex Kit in 156 Wuzhong Hui individuals. The genetic polymorphisms and population genetic relationships were analysed and explored via pairwise Fst, principal component analysis, multidimensional scaling plots, phylogenetic tree, and structure.Results: The combined power of discrimination (CPD) and the combined probability of exclusion (CPE) were 0.9999999999899 and 0.9880, respectively. Population genetic diversity and affinity were associated with geographic origin and linguistic affiliation.Conclusions: The 30 Indels can be utilised as an important tool in forensic personal identification and as a supplementary method in paternity testing in Wuzhong Hui. The Wuzhong Hui people have a close genetic relationship with populations of geographical proximity and Sinitic-speaking populations, while they are different from other continental populations and Turkic-speaking populations.

Genetic diversity of 17 autosomal STR loci in Meizhou Hakka population.

The genetic polymorphism of 17 autosomal short tandem repeat (STR) loci included in the PowerPlex® 18D System was evaluated from 638 unrelated healthy Han individuals of Meizhou in Guangdong Province, Southern China. The values of combined power of discrimination (CPD) and the combined probability of exclusion (CPE) were observed as 0.999999999999999 and 0.999999933. Penta E showed the highest values of polymorphism information content (0.9073), expected heterozygosity (0.9147), and observed heterozygosity (0.9373), whereas TPOX showed the lowest (0.5373, 0.6035, and 0.6082). Furthermore, both of the PCA plot and neighbor-joining phylogenetic tree showed that the Meizhou Hakka population has a relatively close genetic relationship with the Guangdong Han population. The results showed that most of these 17 autosomal STR loci were highly informative and can be effective for forensic individual identification and paternity testing in Meizhou Hakka population.

Population genetic data from 23 autosomal STR loci of Huaxia Platinum system in the Jining Han population.

BackgroundGenetic polymorphisms at 23 short tandem repeat (STR) loci were investigated in 1,215 Jining Han individuals from Jining city, Shandong province, eastern China.MethodsWe used population genetic data of 23 autosomal STR loci included in the Huaxia Platinum system to evaluate 1,215 unrelated Chinese Han individuals in the Jining Han population. Allele frequencies and forensic parameters of the STR loci were determined and genetic relationships among the Jining Han and other Chinese populations were evaluated.ResultsIn total, we observed 321 alleles, with frequencies ranging from 0.00041 to 0.52222. The combined discrimination power and probability of excluding paternity were 0.99999999999999999999999999919 and 0.99999999962, respectively. No deviations from HWE were observed at any loci. Population comparisons showed that the Xinjiang groups (Uyghur and Kazakh) and the Mongolian and Tibetan groups were isolated, while the Jining Han population clustered together with other populations, except the Guizhou Han population.ConclusionThis study demonstrated that 23 autosomal STR loci included in the Huaxia Platinum system are highly polymorphic and suitable for personal forensic identification and paternity testing in this population.

Development and application of a nonbinary SNP-based microhaplotype panel for paternity testing involving close relatives

Paternity testing involving close relatives is facing challenges in the field of forensic genetics. Microhaplotype has been proposed as a promising genetic marker for their low mutation rates and high discrimination power recently. In this study, we selected 30 microhaplotypes from 1000 genome projects, including one non-binary SNP, and other six microhaplotypes from published studies containing only binary SNPs to established a panel of microhaplotypes for paternity testing. Most microhaplotypes generated a high effective number of alleles (Ae) with the harmonic mean value of Ae of 3.91 and the arithmetic mean value of heterozygosity of 0.74, respectively. We collected 54 unrelated individuals and 53 samples from six extended families. It was noting that 13 samples from six extended families were unrelated so they were also included in unrelated individuals. The pedigrees of 38 parent–child duos, 55 uncle/aunt/grandparent–child duos (non-biological parent-child duos) and 29 full sibling pairs were constructed based on 53 samples from six extended families. The genotype and haplotype results demonstrated that the combined power of discrimination (CPD) reached 0.99999999999999999999999999999999799 and the cumulative probability of exclusion (CPE) reached 0.999999999999548. The combined probability of excluding relatives (uncle/aunt/grandparent) (CPER) was 0.999999993 (>0.9999), indicating that our panel had good effectiveness in preventing the misinterpretation of close relatives being biological parents. For 38 parent–child duos, the CPI by using the microhaplotypes panel was higher than the one by using Goldeneye 20A kit due to higher polymorphism and more loci in our panel. For 55 non-biological parent-child duos, the CPIs by using STR loci could not help determine 9 non-biological parent-child duos as “exclusions” of paternity while the CPIs by using microhaplotype loci could not help exclude the parenthood of 4 non-biological parent-child duos (CPI > 0.0001). Using the CPI derived from both datasets of STRs and microhaplotypes, all the non-biological parent-child duos could be considered as exclusions. The efficiency of excluding close relatives for this panel was evaluated by analyzing the parameters of 2000 simulated pairs, and the effectiveness was 0.988 at the threshold of t1 = 4 and t2 = −4. Moreover, the average Log10 combined full sibling index (CFSI) for all 29 full sibling pairs was about 7.55 after physical linkage taken account. These data demonstrated that this nonbinary SNPs-based microhaplotype panel has advantages in paternity testing, especially in STR mutated or close relatives involved cases.

Genetic polymorphism of 20 autosomal short tandem repeats (STRs) in Himachal Pradesh population, India.

Genetic diversity indices and forensic parameters at 20 autosomal short tandem repeat (STR) loci were evaluated in 233 unrelated individuals of Himachal Pradesh, India. In total, 255 alleles were observed with an average of 11.25 ± 0.88 alleles per locus. None of the loci deviated from Hardy Weinberg Equilibrium. The most polymorphic and discriminative locus was Penta E. The combined power of exclusion and the combined power of discrimination were found to be 0.99 and 1. Additionally, the genetic relationship of the Himachal Pradesh population with the populations of the neighboring state was also investigated. All the STR loci were found polymorphic, and the select panel of STRs was found suitable for population genetic studies and forensic analysis.

Genomic blueprint of population of Rajasthan based on autosomal STR markers

Aim: Genetic diversity and forensic efficacy of 20 autosomal STR genetic markers were investigated in a highly diverse population of Rajasthan, a state in north-western India.Subjects and methods: In this study, 317 blood samples from unrelated healthy individuals were directly amplified using the PowerPlex® 21 multiplex system (Promega). Amplified products were separated by capillary electrophoresis using a Genetic Analyser –3500 XL (Thermo Fisher Scientific). The data thus obtained was statistically analysed using population genetic software.Results: The studied population showed genetic affinity with the geographically close populations. The locus Penta-E was found to be the most polymorphic with a value of 0.90 in the studied population. The combined discrimination power (CPD) and combined power of exclusion (CPE) were observed as >0.999999999 and 0.999999997, respectively, for all the studied 20 autosomal STR loci. The combined probability of match (CPm) was 1.39 × 10−25 and combined paternity index (CPI) was 3.66 × 108 for all the studied loci.Conclusion: The results conclusively support the hypothesis that the studied autosomal STR loci are polymorphic in nature and, besides being useful in forensic applications they can also be applied in anthropological and other population genetic studies. This study supports the ‘isolation-by-distance’ model. Genetic data obtained from this study will enrich the population data bank.

An innovative panel containing a set of insertion/deletion loci for individual identification and its forensic efficiency evaluations in Chinese Hui ethnic minority.

BackgroundIndividual identification is one of the most important tasks in the field of forensic genetics. Insertion/Deletion (InDel) polymorphism marker has been a promising marker for individual identification. However, a part of InDel loci in commonly used commercial kit show low polymorphisms in Chinese populations.MethodsWe evaluated a panel of 35 InDel loci constructed previously for individual identifications in Hui group. Subsequently, population data of three Chinese populations from 1,000 Genomes Project database were used to evaluate individual identification performance of these 35 InDels. Forensic parameters, such as heterozygosity, power of exclusion, match probability and power of discrimination, were calculated to evaluate the forensic efficiency of these loci in Hui group. The heatmap of insertion allelic frequencies, Nei's genetic distances, pairwise fixation index values, principal component analyses and admixture analyses were used to analyze the genetic differentiations and structure between Hui group and other populations.ResultsIn studied Hui group, besides rs3054057, polymorphism information content values of the remaining loci were greater than 0.3. Values of expected heterozygosity of these loci were close to 0.5. The combined power of discrimination and power of exclusion values were 0.99999999999999659609 and 0.998682, respectively. Analyses of population genetics revealed that Chinese Hui group had closer genetic relationships with East Asian populations than other intercontinental populations.ConclusionThe forensic statistical analyses revealed these loci showed relatively high genetic polymorphisms in Chinese Hui group, and could be served as a useful tool for individual identifications in Hui group. Population genetic evaluations indicated that Chinese Hui group had close genetic relationships with East Asian populations.

Allelic frequencies of fifteen autosomal STRs in the northeastern Thai people.

We genotyped 15 autosomal STRs loci in 1780 unrelated northeastern Thai individuals. Allele frequencies were computed and all of the loci reached Hardy-Weinberg equilibrium. The forensic parameter results showed high discrimination values which are suitable for forensic personal identification and paternity testing; the combined discrimination power and probability of excluding paternity were 0.9999999999999999999999 and 0.999998449, respectively. Genetic relatedness of northeastern Thais with comparable Thai and Asian populations using phylogenetic analysis revealed close genetic relationship between Mainland Southeast Asian populations and southern Chinese populations.

Investigation of the forensic GlobalFiler loci in the genetically isolated Circassian subpopulation in Jordan

Circassians are a Caucasian ethnic group who make up a significant minority in Jordan. Although other ethnic groups have been the subject of forensic genetic analysis, no published study has investigated the forensic genetic efficiency of short tandem repeats (STRs) in Circassians, neither in Jordan nor in any other country. The main objective of the current study is to determine the allelic frequencies and evaluate the forensic efficiency parameters of 21 highly polymorphic autosomal STR loci among the Circassian subpopulation in Jordan. The GlobalFiler loci were amplified using DNA extracted from the whole blood samples of 150 Jordanian Circassians. The SE33 locus was found to be the most informative and polymorphic STR marker while TPOX was the least informative. However, allele 8 of TPOX was the most common across all of the investigated 21 loci in Jordanian Circassians. The combined matching probability (CMP) and combined power of discrimination (CPD) were 5.02E-24 and 0.9999999, respectively.

A unified STR profiling system across multiple species with whole genome sequencing data

BackgroundShort tandem repeats (STRs) serve as genetic markers in forensic scenes due to their high polymorphism in eukaryotic genomes. A variety of STRs profiling systems have been developed for species including human, dog, cat, cattle, etc. Maintaining these systems simultaneously can be costly. These mammals share many high similar regions along their genomes. With the availability of the massive amount of the whole genomics data of these species, it is possible to develop a unified STR profiling system. In this study, our objective is to propose and develop a unified set of STR loci that could be simultaneously applied to multiple species.ResultTo find a unified STR set, we collected the whole genome sequence data of the concerned species and mapped them to the human genome reference. Then we extracted the STR loci across the species. From these loci, we proposed an algorithm which selected a subset of loci by incorporating the optimized combined power of discrimination. Our results show that the unified set of loci have high combined power of discrimination, >1−10−9, for both individual species and the mixed population, as well as the random-match probability, <10−7 for all the involved species, indicating that the identified set of STR loci could be applied to multiple species.ConclusionsWe identified a set of STR loci which shared by multiple species. It implies that a unified STR profiling system is possible for these species under the forensic scenes. The system can be applied to the individual identification or paternal test of each of the ten common species which are Sus scrofa (pig), Bos taurus (cattle), Capra hircus (goat), Equus caballus (horse), Canis lupus familiaris (dog), Felis catus (cat), Ovis aries (sheep), Oryctolagus cuniculus (rabbit), and Bos grunniens (yak), and Homo sapiens (human). Our loci selection algorithm employed a greedy approach. The algorithm can generate the loci under different forensic parameters and for a specific combination of species.

Forensic features and genetic structure of the Hotan Uyghur inferred from 27 forensic markers

Background: The Uyghur is the fifth largest group in China and also the largest ethnic minority in Xinjiang.Aim: To explore the genetic variations of 27 forensic genetic markers included in the newly developed SureID® PanGlobal Human DNA Identification System and analyse the genetic relationship between Xinjiang Uyghur and their neighbours.Subjects and methods: We genotyped 27 markers in 2,189 unrelated Uyghur individuals from the Hotan Prefecture in Southwest Xinjiang. Comprehensive population genetic studies among Chinese populations and worldwide populations were conducted via various statistics.Results: The combined power of discrimination (CPD) and the combined power of exclusion (CPE) of the new-generation autosomal STR amplification system in the Hotan Uyghur are 9,9999-E01 and 9,9999-E01, respectively. Population genetic studies indicate that the Hotan Uyghur show a close genetic relationship with geographically different Uyghurs and Kazakhs, while significant genetic differentiation exists between the Hotan Uyghur and some ethnicities from other non-Turkic-speaking populations. The results of population comparisons among the 52 worldwide populations demonstrate that geographically approached intercontinental populations have close genetic relationships.Conclusions: 24 autosomal STRs are highly polymorphic and informative in the Uyghur and this system is suitable for forensic personal identification and paternity testing. Our findings not only reveal that Chinese Uyghur is a homogenous population based on forensic genetic markers, but also indicate that population genetic affinity is closely related to the adjacent populations with common ethnic origin.

Assessment of genetic polymorphism at 20 autosomal STR loci in scheduled caste population of Himachal Pradesh.

In this study, we evaluated the genetic diversity indices and forensic parameters of scheduled caste population of Himachal Pradesh, India, at 20 autosomal STR loci. Altogether, 233 alleles were observed with an average of 11.65 ± 0.88 alleles per locus. In exception of locus D13S317, no loci deviated from Hardy Weinberg equilibrium. Locus Penta E was found to be the most polymorphic and discriminative loci. The combined power of discrimination and the combined power of exclusion were 1 and 0.999. Further, we established the phylogenetic relationship between the scheduled caste population of Himachal Pradesh and 14 other populations of India. We found 20 autosomal STR loci used in the present study were polymorphic and can be used in population genetic studies and forensic related case works.

Population genetics of 30 insertion/deletion polymorphisms in the Kuwaiti population

This study evaluates the forensic utility of the 30 insertion and deletion (indel) markers contained in the Qiagen Investigator® DIPplex kit in the Kuwaiti population (n = 150). All but one of the 30 markers were shown to conform to the expectations of the Hardy-Weinberg Equilibrium. Linkage disequilibrium tests showed no statistically significant deviation from independence. The high combined power of discrimination (CPD > 99.999%) and low combined match probability (CMP) of 2.736 × 10−13 provide a satisfactory level of discrimination, allowing the DIPplex loci to be used as forensic markers for individual identification in Kuwait. The paternity indices indicate the usefulness of the DIPplex kit as a supplementary typing system for challenging paternity cases in Kuwait.

Phylogenetic relationship and genetic history of Central Asian Kazakhs inferred from Y-chromosome and autosomal variations.

The Xinjiang Uyghur Autonomous Region of China (XUARC) with 47 ethnic groups is a very colorful ethnic region of China, harboring abundant genetic and cultural diversity. The Kazakhs are the third largest ethnic group (7.02%) after Uyghur (46.42%) and Han (38.99%) in Xinjiang, but their genetic diversity and forensic characterization are poorly understood. In the current study, we genotyped 15 autosomal short tandem repeat (STR) loci and ten Y-STRs in 889 individuals (659 male and 230 female) collected from Kazak population of the Ili Kazak Autonomous Prefecture using AGCU Expressmarker 16 and 10Y-STR Kit (EX16 + 10Y). For autosomal STRs, we observed a total of 174 different alleles ranging from 6 to 34.2 repeat units and FGA showed the greatest power of discrimination (20 alleles) in Ili Kazakh population. We have not observed departures from Hardy-Weinberg equilibrium (HWE) after sequential Bonferroni correction and only found a minimal departure from linkage equilibrium (LE) for a very small number of pairwise combinations of loci. The combined power of exclusion (CPE) was 0.99999998395 and combined power of discrimination (CPD) was 99.999999999999999798%. For Y-STRs, we observed a total of 496 different haplotypes in these ten Y-STR loci. The gene diversities ranged from 0.5023 (DYS391) to 0.8357 (DYS385a/b). The overall haplotype diversity (GD) was 0.9985 with random matching probability (RMP) of 0.0015. The results of population genetic analysis based on both autosomal and Y-chromosome STRs demonstrated that the genetic affinity among populations is generally consistent with ethnic, linguistic, and continental geographical classifications.