Random Match Probability Research Articles

Developmental Validation of the Microreader 23HS Plex ID System: A Novel Supplementary Non-CODIS STR Multiplex Assay for Forensic Application.

A novel supplementary non-CODIS STR multiplex assay designated as the "Microreader 23HS Plex ID System" was developed. The Microreader 23HS Plex ID System enables simultaneous profiling of 23 STR loci and the amelogenin locus. The majority of these loci are non-CODIS STRs (D4S2408, D9S2157, D20S161, D3S2459, D18S1364, D13S305, D1S2142, D19S400, D6S1017, D7S1517, D2S1776, D2S1360, D3S1744, D16S3391, D3S1545, D11S4463, D20S85, D1S549, D10S2325, D21S2055), with the exception of three CODIS STRs (D2S441, D12S391, and D22S1045). Followed the recommendations of Scientific Working Group on DNA Analysis Methods (SWGDAM) and the Chinese validation standards, a comprehensive set of validation studies were conducted, encompassing PCR conditions, stutter ratio and peak height balance, sensitivity, precision and accuracy, reproducibility, species specificity, inhibition, as well as mixture testing. The results demonstrated that the Microreader 23HS Plex ID System is a reliable and robust assay, with well-balanced peak heights, high precision and accuracy, species specificity, and resistance to common inhibitors. The sensitivity of the assay was determined to be 0.125ng of template DNA. In mixture study, all minor alleles were detected in two-sample mixtures across various ratios (1:19, 1:9, 1:4, 3:7, 2:3, 1:1, 3:2, 4:1, 9:1, and 19:1). In population study, a total of 500 unrelated individuals of Han ethnicity from East China were genotyped. The allele frequencies and forensic population genetic parameters were calculated, with a cumulative random match probability of 7.757×10-27, and a total power of discrimination exceeding 0.999,999,999,999,999,999,999,999,99. In conclusion, the Microreader 23HS Plex ID System shows promise as a valuable supplementary tool for forensic applications, particularly in addressing complex kinship testing and challenges posed by STR mutation.

Feasibility study of a single-primer extension-based microhaplotype NGS system.

DNA degradation has been a thorny problem in forensic science. Shortening the amplicon length of the genetic markers improves the analysis of degraded DNA effectively. Microhaplotype (MH) has been proposed as a potential genetic marker that can be used for degraded DNA analysis. In the present study, a 146-plex MH-next-generation sequencing (NGS) system with an average Ae of 6.876 was constructed. Unlike other MH studies, a single-primer extension (SPE)-based NGS library preparation method was used to improve the detection of MH markers for degraded DNA. SPE employs a locus-specific and universal primer to amplify target fragments, reducing the necessity for complete fragment sequences. SPE might effectively mitigate the impact of degradation on amplification. However, SPE produces amplicons of varying lengths, posing challenges in allele calling for SPE-NGS data. To address this issue, this study proposed a flexible allele-calling strategy to improve amplicon detection. In addition, this study evaluated the forensic efficacy of the system using 12 low-template samples (from 1ng to 7.8pg), 10 mock-degraded DNA with various degrees of degradation, and 8 forensic casework samples. When the template is as low as 7.8pg, our system can accurately detect at least 37 loci and achieves a random match probability (RMP) of 10-30 using the complete allele-calling strategy. Eighty-two loci can be detected, and RMP can reach 10-54 using a flexible allele-calling strategy. After 150min of 98°C treatment, 36 loci can still be detected, and an RMP of 10-5 can be obtained using the flexible allele-calling strategy. Furthermore, the number of single nucleotide polymorphism detected at different DNA amounts and degradation levels suggests that the SPE method combined with a flexible allele-calling strategy is effective.

Mitochondrial Control Region Database of Hungarian Fallow Deer (Dama dama) Populations for Forensic Use.

The evidential value of an mtDNA match between biological remains and their potential donor is determined by the random match probability of the haplotype. This probability is based on the haplotype's population frequency estimate. Consequently, implementing a population study representative of the population relevant to a forensic case is vital to correctly evaluating the evidence. The emerging number of poaching cases and the limited availability of such data emphasizes the need for an improved fallow deer mtDNA population databank for forensic purposes, including targeting the entire mitochondrial control region. By sequencing a 945-base-pair-long segment of the mitochondrial control region in 138 animals from five populations in Hungary, we found four different haplotypes, including one which had not yet been described. Our results, supplemented with data already available from previous research, do not support the possibility of determining the population of origin, although some patterns of geographical separation can be distinguished. Estimates of molecular diversity indicate similarly low mtDNA diversity (Hd = 0.565 and π = 0.002) compared to data from other countries. The calculated random match probability of 0.547 shows a high probability of coincidence and, therefore, a limited capacity for exclusion. Our results indicate that despite the overall low genetic diversity of mtDNA within the Hungarian fallow deer samples, a pattern of differentiation among the regions is present, which can have relevance from a forensic point of view.

An overview of autosomal STRs and identity SNPs in a Norwegian population using massively parallel sequencing

In recent years, probabilistic genotyping software has been adapted for the analysis of massively parallel sequencing (MPS) forensic data. Likelihood ratios (LR) are based on allele frequencies selected from populations of interest. This study provides an outline of sequence-based (SB) allele frequencies for autosomal short tandem repeats (aSTRs) and identity single nucleotide polymorphisms (iSNPs) in 371 individuals from Southern Norway. 27 aSTRs and 94 iSNPs were previously analysed with the ForenSeq™ DNA Signature Prep Kit (Verogen). The number of alleles with frequencies less than 0.05 for sequenced-based alleles was 4.6 times higher than for length-based alleles. Consistent with previous studies, it was observed that sequence-based data (both with and without flanks) exhibited higher allele diversity compared to length-based (LB) data; random match probabilities were lower for SB alleles confirming their advantage to discriminate between individuals. Two alleles in markers D22S1045 and Penta D were observed with SNPs in the 3´ flanking region, which have not been reported before. Also, a novel SNP with a minor allele frequency (MAF) of 0.001, was found in marker TH01. The impact of the sample size on minor allele frequency (MAF) values was studied in 88 iSNPs from Southern Norway (n = 371). The findings were then compared to a larger Norwegian population dataset (n = 15,769). The results showed that the smaller Southern Norway dataset provided similar results, and it was a representative sample. Population structure was analyzed for regions within Southern Norway; FST estimates for aSTR and iSNPs did not indicate any genetic structure. Finally, we investigated the genetic differences between Southern Norway and two other populations: Northern Norway and Denmark. Allele frequencies between these populations were compared, and we found no significant frequency differences (p-values > 0.0001). We also calculated the pairwise FST values per marker and comparisons between Southern and Northern Norway showed small differences. In contrast, the comparisons between Southern Norway and Denmark showed higher FST values for some markers, possibly driven by distinct alleles that were present in only one of the populations. In summary, we propose that allele frequencies from each population considered in this study could be used interchangeably to calculate genotype probabilities.

Evaluation of the usefulness of insertion-null markers in critical skeletal remains

Forensic DNA analysis in compromised skeletal remains may pose challenges due to DNA degradation, often resulting in partial or negative autosomal STRs profiles. To address this issue, alternative approaches such as mitochondrial DNA or SNPs typing may be employed; however, they are labour-intensive and costly. Insertion-null alleles (INNULs), short interspersed nuclear elements, have been suggested as a valuable tool for human identification in challenging samples due to their small amplicon size. A commercial kit including 20 INNULs markers along with amelogenin (InnoTyper® 21) has been developed. This study assesses its utility using degraded skeletal remains, comparing the results obtained (the number of detected alleles, RFU values, PHR, and the number of reportable markers) to those obtained using GlobalFiler™. Subsequently, the random match probability of the two profiles for each sample was determined using Familias version 3 to evaluate the power of discrimination of the results obtained from each kit. In every sample, InnoTyper® 21 yielded more alleles, higher RFU values, and a greater number of reportable loci. However, in most cases, both profiles were similarly informative. In conclusion, InnoTyper® 21 serves as a valuable complement to the analysis of challenging samples in cases where a poor or negative profile was obtained.

Population genetic analyses of Eastern Chinese Han nationality using ForenSeq™ DNA Signature Prep Kit.

Currently, the most commonly used method for human identification and kinship analysis in forensic genetics is the detection of length polymorphism in short tandem repeats (STRs) using polymerase chain reaction (PCR) and capillary electrophoresis (CE). However, numerous studies have shown that considerable sequence variations exist in the repeat and flanking regions of the STR loci, which cannot be identified by CE detection. Comparatively, massively parallel sequencing (MPS) technology can capture these sequence differences, thereby enhancing the identification capability of certain STRs. In this study, we used the ForenSeq™ DNA Signature Prep Kit to sequence 58 STRs and 94 individual identification SNPs (iiSNPs) in a sample of 220 unrelated individuals from the Eastern Chinese Han population. Our aim is to obtain MPS-based STR and SNP data, providing further evidence for the study of population genetics and forensic applications. The results showed that the MPS method, utilizing sequence information, identified a total of 486 alleles on autosomal STRs (A-STRs), 97 alleles on X-chromosome STRs (X-STRs), and 218 alleles on Y-chromosome STRs (Y-STRs). Compared with length polymorphism, we observed an increase of 260 alleles (157, 31, and 72 alleles on A-STRs, X-STRs, and Y-STRs, respectively) across 36 STRs. The most substantial increments were observed in DYF387S1 and DYS389II, with increases of 287.5% and 250%, respectively. The most increment in the number of alleles was found at DYF387S1 and DYS389II (287.5% and 250%, respectively). The length-based (LB) and sequence-based (SB) combined random match probability (RMP) of 27 A-STRs were 6.05E-31 and 1.53E-34, respectively. Furthermore, other forensic parameters such as total discrimination power (TDP), cumulative probability of exclusion of trios (CPEtrio), and duos (CPEduo) were significantly improved when using the SB data, and informative data were obtained for the 94 iiSNPs. Collectively, these findings highlight the advantages of MPS technology in forensic genetics, and the Eastern Chinese Han genetic data generated in this study could be used as a valuable reference for future research in this field.

日本人集団において個人を識別するのに必要なSTRとSNPの最小座位数

For this study, we investigated the minimum number of short tandem repeat (STR) and single nucleotide polymorphism (SNP) loci sufficient for personal identification in the Japanese population. A guidance for the data volume that should be treated as personal information was presented here. The uniqueness of individual genotypes was evaluated according to the Scientific Working Group on DNA Analysis Methods interpretation guideline, using the probability that another individual would have the same genotype by chance. In the Japanese population, the threshold of random match probability sufficient for personal identification was 8.15×10－11. In STR, it was considered that when 9 or more of the 21 autosomal STR loci of the GlobalFiler system were combined, they should correspond to personal information. For SNP, a total of 112 loci should be required for identification when cumulating the number of loci at the minor allele frequency interval of 0.01. However, based on the median of allele distribution, a total of 47 loci were necessary to reach below the threshold. Furthermore, we simulated the number of the required loci when the size of the population was variable. Since genome data is already widely used in society, we need to recognize that strict management of genome data are essential from the viewpoint of protecting personal information.

A robust interpolation-based method for forensic soil provenancing: A Bayesian likelihood ratio approach

Soil is a complex and spatially variable material that has a demonstrated potential as a useful evidence class in forensic casework and intelligence operations. Here, the capability to spatially constrain police search areas and prioritise resources by triaging areas as low and high interest is advantageous. Conducted between 2017 and 2021, a forensically relevant topsoil survey (0–5 cm depth; 1 sample per 1 km2) was carried out over Canberra, Australia, aiming to document the distribution of chemical elements in an urban/suburban environment, and of acting as a testbed for investigating various aspects of forensic soil provenancing. Geochemical data from X-Ray Fluorescence (XRF; for total major oxides) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS; for trace elements) following a total digestion (HF + HNO3) of the fused XRF beads were obtained from the survey’s 685 topsoil samples (plus 138 additional quality control samples and six “Blind” simulated evidentiary samples). Using those “Blind” samples, we document a likelihood ratio approach where for each grid cell the analytical similarity between the grid cell and evidentiary sample is attributed from a measure of overlap between the two Cauchy distributions, including appropriate uncertainties. Unlike existing methods that base inclusion/exclusion on an arbitrary threshold (e.g., ± three standard deviations), our approach is free from strict binary or Boolean thresholds, providing an unconstrained gradual transition dictated by the analytical similarity. Using this provenancing model, we present and evaluate a new method for upscaling from a fine (25 m x 25 m) interpolated grid to a more appropriate coarser (500 m x 500 m) grid. In addition, an objective method using Random Match Probabilities for ranking individual variables to be used for provenancing prior to receiving evidentiary material was demonstrated. Our results show this collective procedure generates more consistent and robust provenance maps when applied to two different interpolation algorithms (e.g., inverse distance weighting, and natural neighbour), with different grid placements (e.g., grid shifts to the north or east) and by different theoretical users (e.g., different computer systems, or forensic geoscientists).

Complete Mitochondrial DNA Genome Variation in the Swedish Population.

The development of complete mitochondrial genome (mitogenome) reference data for inclusion in publicly available population databases is currently underway, and the generation of more high-quality mitogenomes will only enhance the statistical power of this forensically useful locus. To characterize mitogenome variation in Sweden, the mitochondrial DNA (mtDNA) reads from the SweGen whole genome sequencing (WGS) dataset were analyzed. To overcome the interference from low-frequency nuclear mtDNA segments (NUMTs), a 10% variant frequency threshold was applied for the analysis. In total, 934 forensic-quality mitogenome haplotypes were characterized. Almost 45% of the SweGen haplotypes belonged to haplogroup H. Nearly all mitogenome haplotypes (99.1%) were assigned to European haplogroups, which was expected based on previous mtDNA studies of the Swedish population. There were signature northern Swedish and Finnish haplogroups observed in the dataset (e.g., U5b1, W1a), consistent with the nuclear DNA analyses of the SweGen data. The complete mitogenome analysis resulted in high haplotype diversity (0.9996) with a random match probability of 0.15%. Overall, the SweGen mitogenomes provide a large mtDNA reference dataset for the Swedish population and also contribute to the effort to estimate global mitogenome haplotype frequencies.

Defining cat mitogenome variation and accounting for numts via multiplex amplification and Nanopore sequencing

Hair shed by domestic cats is a potentially useful source of forensic evidence. Analysable hair DNA is predominantly mitochondrial, but the recent domestication history of cats means that mtDNA diversity is low. A 402-bp control region segment is usually sequenced, defining only a small number of distinct haplotypes in populations. Previously, we used a long-amplicon approach to sequence whole mitogenomes in a sample of blood DNAs from 119 UK cats, greatly increasing observed diversity and reducing random match probabilities. To exploit this variation for forensic analysis, we here describe a multiplex system that amplifies the cat mitogenome in 60 overlapping amplicons of mean length 360 bp, followed by Nanopore sequencing. Variants detected in multiplex sequence data from unrooted hair completely mirror those from long-amplicon data from blood from the same individuals. However, applying the multiplex to matched blood DNA reveals additional sequence variants which derive from the major feline nuclear mitochondrial insertion sequence (numt), which covers 7.9 kb of the 17-kb mitogenome and exists in multiple tandem copies. We use long-amplicon Nanopore sequencing to investigate numt variation in a set of cats, together with an analysis of published genome sequences, and show that numt arrays are variable in both structure and sequence, thus providing a potential source of uncertainty when nuclear DNA predominates in a sample. Forensic application of the multiplex was demonstrated by matching hairs from a cat with skeletal remains from its putative mother, both of which shared a globally common haplotype at the control region. The random match probability in this case with the CR 402-bp segment was 0.21 and this decreased to 0.03 when considering the whole mitogenome. The developed multiplex and sequencing approach, when applied to cat hair where nuclear DNA is scarce, can provide a reliable and highly discriminating source of forensic genetic evidence from a single hair. The confounding effect of numt co-amplification in degraded samples where mixed sequences are observed can be mitigated by variant phasing, and by comparison with numt sequence diversity data, such as those presented here.

Population analysis of complete mitogenomes for 334 samples from El Salvador

The use of mitochondrial DNA (mtDNA) in the field of forensic genetics is widely spread mainly due to its advantages when identifying highly degraded samples. In this sense, massive parallel sequencing has made the analysis of the whole mitogenome more accessible, noticeably increasing the informativeness of mtDNA haplotypes. The civil war (1980–1992) in El Salvador caused many deaths and disappearances (including children) all across the country and the economic and social instability after the war forced many people to emigration. For this reason, different organizations have collected DNA samples from relatives with the aim of identifying missing people. Thus, we present a dataset containing 334 complete mitogenomes from the Salvadoran general population. To the best of our knowledge, this is the first publication of a nationwide forensic-quality complete mitogenome database of any Latin American country. We found 293 different haplotypes, with a random match probability of 0.0041 and 26.6 mean pairwise differences, which is similar to other Latin American populations, and which represent a marked improvement from the values obtained with just control region sequences. These haplotypes belong to 54 different haplogroups, being 91% of them of Native American origin. Over a third (35.9%) of the individuals carried at least a heteroplasmic site (excluding length heteroplasmies). Ultimately, the present database aims to represent mtDNA haplotype diversity in the general Salvadoran populations as a basis for the identification of people that disappeared during or after the civil war.

Informative Relevance of 11 Microsatellite Loci for Forensic DNA-Identification of Wild and Farm American Minc (<i>Mustela vison</i>) in Belarus

American mink is involved in economic activity of the Republic of Belarus since it belongs to resource hunting species as well as breeds for fur production. We propose identification test system consisting of 11 microsatellite DNA loci designed for forensic investigation of cases of illegal hunting and animals stealing for precious furs. Informative relevance of the test system studied using two samples of farm minks and a sample from a wild population of M. vision geographically isolated from fur farms. The significant genetic differences between wild and farmed minks (Fst = 0.04397, P 0.05) showed with random match probabilities of 11-locus genotypes calculated with and without taking into account the Fst value differing by two orders (1.84 × 10–8 and 1.39 × 10–10 respectively). As concerned to forensic DNA analysis, the reference databases should be formed for wild and farm animals separately.

The Analysis of Genetic Polymorphism on Mitochondrial Hypervariable Region III in Thai Population.

Mitochondrial DNA (mtDNA) analysis is a genetic marker for human identification, especially matrilineal inheritance. Hypervariable regions (HVR) I and II of mtDNA have been currently performed for human identification worldwide. Further examination of HVRIII has been conducted with the aim of enhancing the power of discrimination. The aim of this research is to provide informative data on the polymorphisms of HVRIII in the Thai population in order to establish a national database for human identification. Thai people who were unrelated through the maternal lineage were recruited for blood collections. The mtDNA was extracted by Chelex extraction, amplified by polymerase chain reaction, and analyzed using Sequencing Analysis Software. The most common mutation in HVRIII was base substitution, followed by deletion and insertion. We discovered 40 unique haplotypes, with haplotype 489C being the most frequent. The haplotype diversity, power of discrimination, and random match probability were 0.8014, 0.7987, and 0.2013, respectively. Five-CA repeats were the most frequently observed in nucleotide positions 514-523. Our database can be employed as supplementary markers in addition to nuclear deoxyribonucleic acid (DNA) markers in forensic investigations. Moreover, the data could potentially enhance genetic identification and anthropological genetics research in Thailand.

Variability of 27 Autosomal STR Loci for the Population of the Republic of Belarus Based on the Mass Parallel Sequencing Data

Variability of 27 autosomal STR loci of the ForenSeq DNA Signature Prep Kit (Illumina) commercial panel was studied using the technology of mass parallel sequencing (MPS) in 733 unrelated individuals representing the population of the Republic of Belarus as well as a population base of MPS allele frequencies for expert probabilistic calculations in human identification and paternity establishment was evaluated. The agreement between genotypes obtained by MPS and capillary electrophoresis (CE) was 99.96%. The number of MPS alleles increased more than two times for eight loci (D12S391, D21S11, D2S1338, vWA, D3S1358, D8S1179, D13S317, D9S1122). Thirteen alleles detected were not included in the STRSeq BioProject catalog of the international online database STRbase 2.0. The random match probability of 27-locus MPS profiles decreased from 1.43 × 10–31 to 2.89 × 10–35, and the combined paternity index increased from 2.08 × 1010 to 3.25 × 1012 compared to CE data.

The effectiveness of various strategies to improve DNA analysis of formaldehyde-damaged tissues from embalmed cadavers for human identification purposes.

Formalin-fixed tissues provide the medical and forensic communities with alternative and often last resort sources of DNA for identification or diagnostic purposes. The DNA in these samples can be highly degraded and chemically damaged, making downstream genotyping using short tandem repeats (STRs) challenging. Therefore, the use of alternative genetic markers, methods that pre-amplify the low amount of good quality DNA present, or methods that repair the damaged DNA template may provide more probative genetic information. This study investigated whether whole genome amplification (WGA) and DNA repair could improve STR typing of formaldehyde-damaged (FD) tissues from embalmed cadavers. Additionally, comparative genotyping success using bi-allelic markers, including INDELs and SNPs, was explored. Calculated random match probabilities (RMPs) using traditional STRs, INDEL markers, and two next generation sequencing (NGS) panels were compared across all samples. Overall, results showed that neither WGA nor DNA repair substantially improved STR success rates from formalin-fixed tissue samples. However, when DNA from FD samples was genotyped using INDEL and SNP-based panels, the RMP of each sample was markedly lower than the RMPs calculated from partial STR profiles. Therefore, the results of this study suggest that rather than attempting to improve the quantity and quality of severely damaged and degraded DNA prior to STR typing, a more productive approach may be to target smaller amplicons to provide more discriminatory DNA identifications. Furthermore, an NGS panel with less loci may yield better results when examining FD samples, due to more optimized chemistries that result in greater allelic balance and amplicon coverage.

Haplotype Diversity of Mitochondrial DNA in the Jat Population of Haryana

Abstract Background: The genetic representation of various population groups has been successfully attempted by studying hypervariable regions of human mitochondrial DNA (mtDNA) for forensic purposes. In this view of the fact, there are very few studies in the northern region of India focusing on mtDNA variations. The usage of mtDNA typing for forensic purposes has however been delayed in most states, especially Haryana, due to lack of mtDNA pool database for Haryana populations. Aims and Objectives: Since, there has been no elaborated mtDNA study on Jat population of Haryana, thus, the genetic variability of Jat population of Haryana was estimated by examining the hypervariable regions (HVI, HVII, and HVIII) of mtDNA. Materials and Methods: Blood samples of maternally unrelated individuals have been collected. Statistical Analysis Used: Different parameters and molecular diversity indices were computed. Results: The polymorphism has been observed with their corresponding haplogroups. The phylogenetic relationship was inferred between different haplogroups. Conclusion: A high level of variation and a low random match probability was observed in all the three hypervariable regions of mtDNA, indicating its utility for forensic purposes.

Characterization of fracture match associations with automated image processing

During the examination of trace evidence, often a realignment along the edges of known and questioned items are made to determine if a physical fit is present and if those objects were once one continuous piece or object. Duct tape is an evidence type in which the evaluation of physical fits is often conducted and is regarded as conclusive evidence of an association between the items. The examination and conclusion of a physical fit between edges relies heavily on examiner discretion to identify distinctive features across the edges since there are no statistical approaches or objective methodologies for the comparison. This study developed an automated image processing and comparison method to quantify tape end matches using cross-correlation scores and an empirical approach to the assessment. Characterization of 150 hand torn duct tape end pair physical fits were also conducted where matching and non-matching sample distributions were created. This study also evaluated partial duct tape edges and the influence this has on a comparison. Given the strength associated with a physical fit and the presence of stretching or deformation along the fractured edge, an understanding of the value these samples have is paramount. Furthermore, random match probabilities were calculated based on the correlation scores from the inter-comparisons to model the weight of evidence or strength of association between the edges. Finally, the study demonstrated that not every true match holds the same association strength through score distributions, but the approach is able to distinguish matching and non-matching samples at edge widths greater than 27 %.

The mitochondrial DNA HVI and HVII sequences and haplogroup distribution in a population sample from Vietnam

Background Mitochondrial DNA (mtDNA) analysis has been used in forensics and requires well-established population databases for statistical interpretations. However, high-quality mtDNA data from Vietnamese population samples have been limited. Aim To examine the mtDNA sequences and haplogroup compositions of a Vietnamese population to provide an mtDNA dataset that can further be used to construct a Vietnamese-specific reference database. Subjects and methods A total of 173 Vietnamese individuals were analysed for two hypervariable regions (HVI and HVII) of mtDNA. Forensic parameters were calculated and haplogroup assignment was performed based on the resulting mtDNA haplotypes. Genetic relationships between the Vietnamese and other Asian populations were investigated through principal component analysis (PCA) and pairwise Fst. Results The Vietnamese population sample consisted of 145 different haplotypes with a random match probability of 0.96%, a power of discrimination of 0.9904, and a haplotype diversity of 0.9962. The samples were assigned to 83 haplogroups that were commonly reported in Asia. PCA and pairwise Fst revealed close relationships of the Vietnamese population with other Asian populations, especially with populations in proximity. Conclusion The results from this study can contribute to the current genetic information content as a supplementary mtDNA reference dataset for forensic investigations and phylogenetic research.

Calibrating the perceived strength of evidence of forensic testimony statements

Pattern comparison disciplines use categorical statements to express conclusions. We measured the strength of evidence for six different scales as perceived by members of the general public and fingerprint examiners. The statements came from different types of scales, and included categorical conclusions, likelihoods, strength of support statements, and random match probabilities. We used an online interface that required participants to first correctly sort the statements in a given conclusion scale, and then place each statement on a single evidence axis that ranged from most support imaginable for same source to most support imaginable for different sources. We analyzed the data using both the raw values and a Thurstone–Mosteller model based on ordinal values. We found systematic differences between examiners and members of the general public, such that examiners distinguished between Identification and Extremely Strong Support for Common Source, while members of the general public did not. Statements that included numerical values tended to be placed lower than categorical conclusions, and members of the general public tended to place the highest categorical conclusion in each scale at the very top of the evidence axis. The results suggest that laypersons can distinguish between statements meant to represent moderate vs strong evidence, but tend to place categorical conclusions above statements that involve numerical values.

State of the Art for Microhaplotypes.

In recent years, the number of publications on microhaplotypes has averaged more than a dozen papers annually. Many have contributed to a significant increase in the number of highly polymorphic microhaplotype loci. This increase allows microhaplotypes to be very informative in four main areas of forensic uses of DNA: individualization, ancestry inference, kinship analysis, and mixture deconvolution. The random match Probability (RMP) can be as small as 10−100 for a large panel of microhaplotypes. It is possible to measure the heterozygosity of an MH as the effective number of alleles (Ae). Ae > 7.5 exists for African populations and >4.5 exists for Native American populations for a smaller panel of two dozen selected microhaplotypes. Using STRUCTURE, at least 10 different ancestral clusters can be defined by microhaplotypes. The Ae for a locus is also identical to the Paternity Index (PI), the measure of how informative a locus will be in parentage testing. High Ae loci can also be useful in missing persons cases. Finally, high Ae microhaplotypes allow the near certainty of seeing multiple additional alleles in a mixture of two or more individuals in a DNA sample. In summary, a panel of higher Ae microhaplotypes can outperform the standard CODIS markers.