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1.
Int J Legal Med ; 137(1): 13-32, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36333511

RESUMO

The evidentiary value of DNA profiles varies depending upon the context in which the DNA was found. Linking a DNA profile to a particular cellular phenotype in mixtures may aid in assessing its evidentiary relevance and value. We report the development of two dual-function high-resolution messenger RNA (mRNA) sequencing assays that can each identify the presence of 6 body fluids/tissues (blood, semen, saliva, vaginal secretions, menstrual blood, skin) and, via coding region SNPs (cSNPs) present in the body fluid-specific mRNA transcripts, directly associate particular body fluids with their specific DNA donors in mixtures. The original blood, semen, and saliva (BSS) assay contains 23 cSNPs for blood, semen, and saliva, while the expanded 6F (all 6 fluids/tissues) assay encompasses the BSS assay and also contains 23 additional cSNPs for vaginal secretions, menstrual blood, and skin. Software tools were developed to infer the identity of the body fluids present as well as providing the corresponding cSNP genotypes. Concomitant genomic DNA assays (BSS-d and 6F-d), required to genotype the same cSNPs from persons of interest/inferred contributors to the body fluid mixture, were also developed. Body fluid specificity was demonstrated by the ability to identify the body fluid origin of single-source and two-fluid admixtures. The discriminatory power (European Caucasians) for all body fluids is 0.957-0.997, with linkage disequilibrium considered. Reciprocal body fluid admixtures (mixture pairs with the same two donors but reversed body fluid types) were used to demonstrate the ability to identify the body fluid source of origin as well as associate the donor of each of the two fluids.


Assuntos
Líquidos Corporais , Feminino , Animais , Saliva , Sêmen , RNA Mensageiro/genética , DNA/genética , Análise de Sequência de RNA , Genética Forense
2.
Int J Legal Med ; 136(1): 93-101, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34212238

RESUMO

Genotype profiling has played a major role in forensics for decades. The technology for detection and discrimination has advanced substantially, from serology to DNA sequence analysis. Currently, there may be situations where there is a need for re-analysis of forensic DNA data that was produced using methodology that is no longer available. An example of this is the allele-specific oligonucleotide hybridization assays used in the 1990s. In the study presented herein, we have developed a multiplex system combining PCR and massively parallel sequencing (MPS) technologies to identify DNA polymorphisms. Our results are consistent with those found in the widely utilized AmpliType PM + DQA1 Amplification and Typing Kit originally marketed by Perkin Elmer. During the course of our studies, it became apparent that paralogous genes for two of the loci, GYPA and HBG2 (formerly HBGG), could have confounded the interpretation of the original assays, and we describe the technical solutions we developed to overcome ambiguity in genotype assignment. This study results in a novel resource enabling the re-analysis of DNA profiling results produced decades past using current day technology.


Assuntos
Impressões Digitais de DNA , Cadeias alfa de HLA-DQ , Sequenciamento de Nucleotídeos em Larga Escala , Alelos , Genótipo , Cadeias alfa de HLA-DQ/genética , Humanos , Reação em Cadeia da Polimerase/métodos
3.
Genes (Basel) ; 11(12)2020 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-33255693

RESUMO

As the field of forensic DNA analysis has started to transition from genetics to genomics, new methods to aid in crime scene investigations have arisen. The development of informative single nucleotide polymorphism (SNP) markers has led the forensic community to question if DNA can be a reliable "eye-witness" and whether the data it provides can shed light on unknown perpetrators. We have developed an assay called the Ion AmpliSeq™ PhenoTrivium Panel, which combines three groups of markers: 41 phenotype- and 163 ancestry-informative autosomal SNPs together with 120 lineage-specific Y-SNPs. Here, we report the results of testing the assay's sensitivity and the predictions obtained for known reference samples. Moreover, we present the outcome of a blind study performed on real casework samples in order to understand the value and reliability of the information that would be provided to police investigators. Furthermore, we evaluated the accuracy of admixture prediction in Converge™ Software. The results show the panel to be a robust and sensitive assay which can be used to analyze casework samples. We conclude that the combination of the obtained predictions of phenotype, biogeographical ancestry, and male lineage can serve as a potential lead in challenging police investigations such as cold cases or cases with no suspect.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/métodos , DNA/genética , Feminino , Genética Forense/métodos , Genômica/métodos , Humanos , Masculino , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Software
4.
Genes (Basel) ; 11(11)2020 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-33202822

RESUMO

For the adoption of massively parallel sequencing (MPS) systems by forensic laboratories, validation studies on specific workflows are needed to support the feasibility of implementation and the reliability of the data they produce. As such, the whole mitochondrial genome sequencing methodology-Precision ID mtDNA Whole Genome Panel, Ion Chef, Ion S5, and Converge-has been subjected to a variety of developmental validation studies. These validation studies were completed in accordance with the Scientific Working Group on DNA Analysis Methods (SWGDAM) validation guidelines and assessed reproducibility, repeatability, accuracy, sensitivity, specificity to human DNA, and ability to analyze challenging (e.g., mixed, degraded, or low quantity) samples. Intra- and inter-run replicates produced an average maximum pairwise difference in variant frequency of 1.2%. Concordance with data generated with traditional Sanger sequencing and an orthogonal MPS platform methodology was used to assess accuracy, and generation of complete and concordant haplotypes at DNA input levels as low as 37.5 pg of nuclear DNA or 187.5 mitochondrial genome copies illustrated the sensitivity of the system. Overall, data presented herein demonstrate that highly accurate and reproducible results were generated for a variety of sample qualities and quantities, supporting the reliability of this specific whole genome mitochondrial DNA MPS system for analysis of forensic biological evidence.


Assuntos
Genoma Mitocondrial , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Reação em Cadeia da Polimerase/métodos , Animais , Biologia Computacional , Genética Forense/métodos , Cabelo , Haplótipos , Humanos , Masculino , Saliva , Sêmen , Sensibilidade e Especificidade , Especificidade da Espécie , Fluxo de Trabalho
5.
Forensic Sci Int Genet ; 49: 102398, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33045522

RESUMO

Microhaplotypes (microhaps or MHs) are novel forensically relevant genetic markers that demand large and appropriate allele frequency datasets for their implementation in casework. In this study we report on the allele frequency data of 74 microhap loci (230 SNPs) included in a newly developed 74-plex assay. The panel was tested on the Ion S5 system on a total of 347 samples from four main U.S. population groups of African, European, East Asian and Southwest Hispanic descent. Overall, frequencies of individual alleles at each locus varied considerably among the different population groups. An increase in the average value of gene diversity was also observed as the number of SNPs per locus increased. Most microhap markers showed no significant deviation from Hardy-Weinberg ratios within any of the individual population samples displaying an average power of discrimination between 0.74 and 0.81 and an average probability of exclusion between 0.32 and 0.39. Moreover, the four population groups had no clear genetic affinities with the exception of U.S. European and U.S. Southwest Hispanic populations, which showed the lowest FST value. STRUCTURE and principal component analyses (PCA) analysis resulted in effective clustering of the four populations with the U.S. European and Southwest Hispanic showing some overlap. These results support the potential use of this sequence-based 74plex-microhaplotype assay for ancestry inference in addition to previously reported human identification and mixture deconvolution capabilities.


Assuntos
Genética Populacional , Haplótipos , Grupos Raciais/genética , Impressões Digitais de DNA , Frequência do Gene , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Polimorfismo de Nucleotídeo Único , Análise de Componente Principal , Análise de Sequência de DNA , Estados Unidos
6.
Forensic Sci Int Genet ; 49: 102367, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32919300

RESUMO

Microhaplotypes are emerging biomarkers for forensic applications. In this study, a sequence-based multiplex assay of 74 microhaplotypes (230 SNPs) was developed on the Ion Torrent S5™ (Thermo Fisher Scientific) system and the potential for its application to mixture deconvolution was explored. The 74 loci are distributed across the autosomal human genome and have Ae (i.e., effective number of alleles) values ranging from 1.307 to 6.010 (median = 2.706) and In (i.e., informativeness) values ranging from 0.096 to 0.660 (median = 0.251); the amplicon sizes range between 157 and 325 bp. The typing performance of the panel was evaluated on a series of in-silico two to five-person DNA mixtures and results were compared to fragment and sequence-based STRs. The 74plex-locus assay was found sensitive down to 0.05 ng of input DNA and effective for the analysis of mixtures at different contributor ratios and input DNA amounts. As expected, none or very partial minor CE-STR profile(s) were reported for highly imbalanced two-person and high-order DNA mixtures while sequencing of STRs enabled the detection of more individual minor alleles. For microhaplotypes, a full minor profile was detected down to a 20:1 ratio at 10 ng and minimal allele dropout at 1 ng of input DNA. A higher rate of allele dropout from the minor donor(s) was reported at 1 ng than 10 ng for three-person mixtures while for four- and five-person mixtures, the same number of dropouts was observed for almost all minor donors. Overall this microhaplotype panel is a powerful tool that can complement and enhance size- and sequence-based STR analysis of forensic DNA mixtures.


Assuntos
DNA/genética , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Repetições de Microssatélites , Análise de Sequência de DNA , Impressões Digitais de DNA/métodos , Humanos , Reação em Cadeia da Polimerase , Polimorfismo de Nucleotídeo Único
7.
Mitochondrion ; 55: 122-133, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32949792

RESUMO

Nuclear mitochondrial DNA segments (NUMTs) are generated via transfer of portions of the mitochondrial genome into the nuclear genome. Given their common origin, there is the possibility that both the mitochondrial and NUMT segments may co-amplify using the same set of primers. Thus, analysis of the variation of the mitochondrial genome must take into account this co-amplification of mitochondrial and NUMT sequences. The study herein builds on data from the study by Strobl et al. (Strobl et al., 2019), in which multiple point heteroplasmies were called with an "N" to prevent labeling NUMT sequences mimicking mitochondrial heteroplasmy and being interpreted as true mitochondrial in origin sequence variants. Each of these point heteroplasmies was studied in greater detail, both molecularly and bioinformatically, to determine whether NUMT or true mitochondrial DNA variation was present. The bioinformatic and molecular tools available to help distinguish between NUMT and mitochondrial DNA and the effect of NUMT sequences on interpretation were discussed.


Assuntos
Núcleo Celular/genética , DNA Mitocondrial/classificação , Mitocôndrias/genética , Sequenciamento Completo do Genoma/métodos , Biologia Computacional/métodos , DNA Mitocondrial/isolamento & purificação , Variação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Filogenia
8.
Forensic Sci Int Genet ; 42: 190-197, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31374458

RESUMO

The Huaxia™ Platinum Kit for short tandem repeat (STR) amplification was designed to meet the needs of the rapidly growing Chinese forensic database. This PCR multiplex allows simultaneous amplification of the following autosomal loci: D3S1358, vWA, D16S539, CSF1PO, TPOX, D8S1179, D21S11, D18S51, Penta E, D2S441, D19S433, TH01, FGA, D22S1045, D5S818, D13S317, D7S820, D6S1043, D10S1248, D1S1656, D12S391, D2S1338, Penta D and the gender-identification markers Yindel, and AMEL. The Huaxia™ Platinum Kit enables direct amplification from blood and buccal samples stored on treated and untreated paper, and features an optimized PCR protocol that yields time to results in less than 45 min. Developmental validation testing followed SWGDAM guidelines and demonstrated that this assay produces reproducible and accurate results. Studies on 798 individuals in 4 major Chinese ethnic groups produced highly concordant results with other commercially available STR genotyping kits. The validation results demonstrate that the Huaxia™ Platinum Kit is a robust and reliable identification system for forensic DNA databasing applications.


Assuntos
Etnicidade/genética , Genética Populacional , Repetições de Microssatélites , Reação em Cadeia da Polimerase Multiplex/métodos , Animais , Povo Asiático/genética , Análise Química do Sangue , China , Impressões Digitais de DNA , Frequência do Gene , Humanos , Mucosa Bucal/química , Especificidade da Espécie , Manejo de Espécimes
9.
Forensic Sci Int Genet ; 42: 244-251, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31382159

RESUMO

The emergence of Massively Parallel Sequencing technologies enabled the analysis of full mitochondrial (mt)DNA sequences from forensically relevant samples that have, so far, only been typed in the control region or its hypervariable segments. In this study, we evaluated the performance of a commercially available multiplex-PCR-based assay, the Precision ID mtDNA Whole Genome Panel (Thermo Fisher Scientific), for the amplification and sequencing of the entire mitochondrial genome (mitogenome) from even degraded forensic specimens. For this purpose, more than 500 samples from 24 different populations were selected to cover the vast majority of established superhaplogroups. These are known to harbor different signature sequence motifs corresponding to their phylogenetic background that could have an effect on primer binding and, thus, could limit a broad application of this molecular genetic tool. The selected samples derived from various forensically relevant tissue sources and were DNA extracted using different methods. We evaluated sequence concordance and heteroplasmy detection and compared the findings to conventional Sanger sequencing as well as an orthogonal MPS platform. We discuss advantages and limitations of this approach with respect to forensic genetic workflow and analytical requirements.


Assuntos
DNA Mitocondrial/genética , Genoma Mitocondrial , Sequenciamento de Nucleotídeos em Larga Escala , Reação em Cadeia da Polimerase Multiplex , Genética Forense/métodos , Haplótipos , Humanos , Filogenia , Análise de Sequência de DNA
10.
Forensic Sci Int Genet ; 41: 93-106, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31063905

RESUMO

Y-chromosomal haplogroups assigned from male-specific Y-chromosomal single nucleotide polymorphisms (Y-SNPs) allow paternal lineage identification and paternal bio-geographic ancestry inference, both being relevant in forensic genetics. However, most previously developed forensic Y-SNP tools did not provide Y haplogroup resolution on the high level needed in forensic applications, because the limited multiplex capacity of the DNA technologies used only allowed the inclusion of a relatively small number of Y-SNPs. In a proof-of-principle study, we recently demonstrated that high-resolution Y haplogrouping is feasible via two AmpliSeq PCR analyses and simultaneous massively parallel sequencing (MPS) of 530 Y-SNPs allowing the inference of 432 Y-haplogroups. With the current study, we present a largely improved Y-SNP MPS lab tool that we specifically designed for the analysis of low quality and quantity DNA often confronted with in forensic DNA analysis. Improvements include i) Y-SNP marker selection based on the "minimal reference phylogeny for the human Y chromosome" (PhyloTree Y), ii) strong increase of the number of targeted Y-SNPs allowing many more Y haplogroups to be inferred, iii) focus on short amplicon length enabling successful analysis of degraded DNA, and iv) combination of all amplicons in a single AmpliSeq PCR and simultaneous sequencing allowing single DNA aliquot use. This new MPS tool simultaneously analyses 859 Y-SNPs and allows inferring 640 Y haplogroups. Preliminary forensic developmental validation testing revealed that this tool performs highly accurate, is sensitive and robust. We also provide a revised software tool for analysing the sequencing data produced by the new MPS lab tool including final Y haplogroup assignment. We envision the tools introduced here for high-resolution Y-chromosomal haplogrouping to determine a man's paternal lineage and/or paternal bio-geographic ancestry to become widely used in forensic Y-chromosome DNA analysis and other applications were Y haplogroup information from low quality / quantity DNA samples is required.


Assuntos
Cromossomos Humanos Y , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , DNA/análise , Degradação Necrótica do DNA , Genética Forense/métodos , Humanos , Masculino , Reação em Cadeia da Polimerase , Reprodutibilidade dos Testes
11.
Int J Legal Med ; 133(3): 731, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30834970

RESUMO

The original version of this article contained an author name error. In this article, Katrina Madella has been corrected to Katrina Maddela.

12.
Int J Legal Med ; 133(3): 719-729, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30758713

RESUMO

Short tandem repeat polymorphisms (STRs) are the standard markers for forensic human identification. STRs are highly polymorphic loci analyzed using a direct PCR-to-CE (capillary electrophoresis) approach. However, STRs have limitations particularly when dealing with complex mixtures. These include slippage of the polymerase during amplification causing stutter fragments that can be indistinguishable from minor contributor alleles, preferential amplification of shorter alleles, and limited number of loci that can be effectively co-amplified with CE. Massively parallel sequencing (MPS), by enabling a higher level of multiplexing and actual sequencing of the DNA, provides forensic practitioners an increased power of discrimination offered by the sequence of STR alleles and access to new sequence-based markers. Microhaplotypes (i.e., microhaps or MHs) are emerging multi-allelic loci of two or more SNPs within < 300 bp that are highly polymorphic, have alleles all of the same length, and do not generate stutter fragments. The growing number of loci described in the literature along with initial mixture investigations supports the potential for microhaps to aid in mixture interpretation and the purpose of this study was to demonstrate that practically. A panel of 36 microhaplotypes, selected from a set of over 130 loci, was tested with the Ion S5™ MPS platform (Thermo Fisher Scientific) on single-source samples, synthetic two-to-six person mixtures at different concentrations/contributor ratios, and on crime scene-like samples. The panel was tested both in multiplex with STRs and SNPs and individually. The analysis of single-source samples showed that the allele coverage ratio across all loci was 0.88 ± 0.08 which is in line with the peak height ratio of STR alleles in CE. In mixture studies, results showed that the input DNA can be much higher than with conventional CE, without the risk of oversaturating the detection system, enabling an increased sensitivity for the minor contributor in imbalanced mixtures with abundant amounts of DNA. Furthermore, the absence of stutter fragments simplifies the interpretation. On casework-like samples, MPS of MHs enabled the detection of a higher number of alleles from minor donors than MPS and CE of STRs. These results demonstrated that MPS of microhaplotypes can complement STRs and enhance human identification practices when dealing with complex imbalanced mixtures.


Assuntos
DNA/análise , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência de DNA , Alelos , Impressões Digitais de DNA , Feminino , Genótipo , Humanos , Masculino , Repetições de Microssatélites , Reação em Cadeia da Polimerase , Polimorfismo de Nucleotídeo Único
13.
Electrophoresis ; 39(21): 2815-2823, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29931757

RESUMO

Massively parallel sequencing is transforming forensic work by allowing various useful forensic markers, such as STRPs and SNPs, to be multiplexed providing information on ancestry, individual and familial identification, phenotypes for eye/hair/skin pigmentation, and the deconvolution of mixtures. Microhaplotypes also become feasible with massively parallel sequencing, these are DNA segments (smaller than 300 nucleotides) that are selected to contain multiple SNPs unambiguously defining three or more haplotype alleles occurring at common frequencies. The physical extent of a microhaplotype can thus be covered by a single sequence read making these loci phase-known codominant genetic systems. Such microhaplotypes supply significantly more information than a single SNP can. Our efforts to develop useful sets of microhaplotypes have already identified 182 such loci that we have studied on a large number of human populations from around the world. We present various analyses on 83 populations in our ongoing study for a subset of the best microhaplotypes currently available illustrating their characteristics and potential utility for ancestry, identification, and mixture deconvolution.


Assuntos
Genética Forense/métodos , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Frequência do Gene , Genética Populacional , Técnicas de Genotipagem/métodos , Humanos , Repetições de Microssatélites , Polimorfismo de Nucleotídeo Único
14.
Int J Legal Med ; 132(6): 1555-1573, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29523969

RESUMO

The GlobalFiler™ PCR Amplification Kit is a single multiplex assay that amplifies a set of 24 markers, which encompass the European Standard Set and CODIS (Combined DNA Index System) recommended composite set of loci. In addition to more loci and a 6-dye chemistry format, the Master Mix has been formulated to allow higher sample loading volume for trace DNA samples. The GlobalFiler™ Kit has been optimized to deliver high performance on casework samples, while also delivering fast thermal cycling, with an amplification time of approximately 80 min. Here, we report the results of the developmental validation study which followed the SWGDAM (Scientific Working Group on DNA Analysis Methods) guidelines and includes data for PCR-based studies, sensitivity, species specificity, stability, precision, reproducibility and repeatability, concordance, stutter, DNA mixtures, and performance on mock casework samples. The results validate the multiplex design as well as demonstrate the kit's robustness, reliability, and suitability as an assay for human identification with casework DNA samples.


Assuntos
Impressões Digitais de DNA , Repetições de Microssatélites , Reação em Cadeia da Polimerase Multiplex/instrumentação , Animais , Osso e Ossos/química , Degradação Necrótica do DNA , Frequência do Gene , Humanos , Grupos Raciais/genética , Reprodutibilidade dos Testes , Especificidade da Espécie
15.
Int J Legal Med ; 132(3): 703-711, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29248957

RESUMO

Microhaplotypes have become a new type of forensic marker with a great ability to identify and deconvolute mixtures because massively parallel sequencing (MPS) allows the alleles (haplotypes) of the multi-SNP loci to be determined directly for an individual. As originally defined, a microhaplotype locus is a short segment of DNA with two or more SNPs defining three or more haplotypes. The length is short enough, less than about 300 bp, that the read length of current MPS technology can produce a phase-known sequence of each chromosome of an individual. As part of the discovery phase of our studies, data on 130 microhaplotype loci with estimates of haplotype frequency data on 83 populations have been published. To provide a better picture of global allele frequency variation, we have now tested 13 more populations for 65 of the microhaplotype loci from among those with higher levels of inter-population gene frequency variation, including 8 loci not previously published. These loci provide clear distinctions among 6 biogeographic regions and provide some information distinguishing up to 10 clusters of populations.


Assuntos
Genética Populacional , Haplótipos , Frequência do Gene , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Polimorfismo de Nucleotídeo Único , Análise de Componente Principal
16.
Forensic Sci Int Genet ; 29: 29-37, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28359046

RESUMO

Today the primary DNA markers used in forensics are short tandem repeat (STR) polymorphisms (STRPs), initially selected because they are highly polymorphic. However, the increasingly common need to deal with samples with a mixture of DNA from two or more individuals sometimes is complicated by the inherent stutter involved with PCR amplification, especially in strongly unbalanced mixtures when the minor component coincides with the stutter range of the major component. Also, the STRPs in use provide little evidence of ancestry of a single source sample beyond broad "continental" resolution. Methodologies for analyzing DNA have become much more powerful in recent years. Massively parallel sequencing (MPS) is a new method being considered for routine use in forensics. Primarily to aid in mixture deconvolution and avoid the issue of stutter, we have begun to investigate a new type of forensic marker, microhaplotype loci, that will provide useful information on mixtures of DNA and on ancestry when typed using massively parallel sequencing (MPS). We have identified 130 loci and estimated their haplotype (allele) frequencies in 83 different population samples. Many of these loci are shown to be highly informative for individual identification and for mixture identification and deconvolution.


Assuntos
Genética Populacional , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala , Polimorfismo de Nucleotídeo Único , Conjuntos de Dados como Assunto , Frequência do Gene , Projeto HapMap , Humanos
17.
Forensic Sci Int Genet ; 24: 164-175, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27459350

RESUMO

Y-chromosomal loci have proven useful in solving investigations where low levels of male DNA are present in a high female DNA background. An intrinsic limitation of Y-STRs compared with autosomal STRs is a reduced power of discrimination due to a lack of recombination throughout most of the Y-chromosome. Thus, in an effort to increase the power of discrimination we have developed a new 6-dye, 27-plex Y-STR system that includes the 17 loci from the Yfiler(®) and Yfiler(®) Direct kits (DYS19, DYS385a/b, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635 (Y GATA C4), and Y GATA H4) plus three highly polymorphic Y-STR loci (DYS460, DYS481, and DYS533), and seven rapidly mutating Y-STR loci (DYF387S1a/b, DYS449, DYS518, DYS570, DYS576, DYS627) which allow for improved discrimination of related individuals. The Yfiler(®) Plus PCR Amplification Kit is a dual application assay designed to amplify DNA from extracted casework and database samples from storage cards and swab lysates via direct amplification. Compared to the Yfiler PCR Amplification Kit, the new multiplex shows increased discrimination of male lineages and also improved performance in inhibited samples, improved balance in male DNA samples mixed with female DNA at ratios >1:1000, and faster time to results. The Yfiler Plus Kit shows very high concordance to the Yfiler Kit but discordance with the PowerPlex(®) Y23 Kit at the DYS481 locus was observed in 2 out of 30 samples tested. This developmental validation work follows the SWGDAM guidelines and demonstrates that the assay is robust and suitable for use on forensic casework and database samples.


Assuntos
Cromossomos Humanos Y , Impressões Digitais de DNA , Repetições de Microssatélites , Reação em Cadeia da Polimerase/instrumentação , Animais , Feminino , Genótipo , Humanos , Masculino , Grupos Raciais/genética , Especificidade da Espécie
18.
Hum Mutat ; 36(12): 1236-47, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26387877

RESUMO

Whole mitochondrial (mt) genome analysis enables a considerable increase in analysis throughput, and improves the discriminatory power to the maximum possible phylogenetic resolution. Most established protocols on the different massively parallel sequencing (MPS) platforms, however, invariably involve the PCR amplification of large fragments, typically several kilobases in size, which may fail due to mtDNA fragmentation in the available degraded materials. We introduce a MPS tiling approach for simultaneous whole human mt genome sequencing using 161 short overlapping amplicons (average 200 bp) with the Ion Torrent Personal Genome Machine. We illustrate the performance of this new method by sequencing 20 DNA samples belonging to different worldwide mtDNA haplogroups. Additional quality control, particularly regarding the potential detection of nuclear insertions of mtDNA (NUMTs), was performed by comparative MPS analysis using the conventional long-range amplification method. Preliminary sensitivity testing revealed that detailed haplogroup inference was feasible with 100 pg genomic input DNA. Complete mt genome coverage was achieved from DNA samples experimentally degraded down to genomic fragment sizes of about 220 bp, and up to 90% coverage from naturally degraded samples. Overall, we introduce a new approach for whole mt genome MPS analysis from degraded and nondegraded materials relevant to resolve and infer maternal genetic ancestry at complete resolution in anthropological, evolutionary, medical, and forensic applications.


Assuntos
DNA Mitocondrial , Genoma Mitocondrial , Sequenciamento de Nucleotídeos em Larga Escala/instrumentação , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Código de Barras de DNA Taxonômico/instrumentação , Código de Barras de DNA Taxonômico/métodos , Código de Barras de DNA Taxonômico/normas , Genômica/instrumentação , Genômica/métodos , Genômica/normas , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala/normas , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
19.
Forensic Sci Int Genet ; 19: 148-155, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26226223

RESUMO

In order to increase the power of discrimination, reduce the possibility of adventitious matches, and expand global data sharing, the CODIS Core Loci Working Group made a recommendation to expand the CODIS core loci from the "required" 13 loci to 20 plus three additional "highly recommended" loci. The GlobalFiler(®) Express Kit was designed to incorporate all 20 required and 3 highly recommended loci along with a novel male-specific Y insertion/deletion marker. The GlobalFiler(®) Express Kit allows simultaneous amplification of the following loci: D3S1358, vWA, D16S539, CSF1PO, TPOX, Yindel, AMEL, D8S1179, D21S11, D18S51, DYS391, D2S441, D19S433, TH01, FGA, D22S1045, D5S818, D13S317, D7S820, SE33, D10S1248, D1S1656, D12S391, and D2S1338. The kit enables direct amplification from blood and buccal samples stored on paper or swab and the chemistry features an optimized PCR protocol that yields time to results in less than an hour. Developmental validation testing followed SWGDAM guidelines and demonstrated the quality and robustness of the GlobalFiler(®) Express Kit over a number of variables. The validation results demonstrate that the 24-locus multiplex kit is a robust and reliable identification assay as required for forensic DNA typing and databasing.


Assuntos
Corantes/química , Reação em Cadeia da Polimerase/instrumentação , Animais , Humanos , Limite de Detecção , Nucleotídeos/análise , Reação em Cadeia da Polimerase/métodos , Reprodutibilidade dos Testes , Especificidade da Espécie
20.
Croat Med J ; 56(3): 218-29, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26088846

RESUMO

AIM: To perform a blind study to assess the capability of the Ion Personal Genome Machine® (PGM™) system to sequence forensically relevant genetic marker panels and to characterize unknown individuals for ancestry and possible relatedness. METHODS: Twelve genomic samples were provided by a third party for blinded genetic analysis. For these 12 samples, the mitochondrial genome and three PGM™ panels containing human identity single nucleotide polymorphisms (SNPs), ancestry informative SNPs, and short tandem repeats (STRs) were sequenced on the PGM™ system and analyzed. RESULTS: All four genetic systems were run and analyzed on the PGM™ system in a reasonably quick time frame. Completeness of genetic profiles, depth of coverage, strand balance, and allele balance were informative metrics that illustrated the quality and reliability of the data produced. SNP genotypes allowed for identification of sex, paternal lineage, and population ancestry. STR genotypes were shown to be in complete concordance with genotypes generated by standard capillary electrophoresis-based technologies. Variants in the mitochondrial genome data provided information on population background and maternal relationships. CONCLUSION: All results from analysis of the 12 genomic samples were consistent with sample information provided by the sample providers at the end of the blinded study. The relatively easy identification of intra-STR allele SNPs offered the potential for increased discrimination power. The promising nature of these results warrants full validation studies of this massively parallel sequencing technology and its further development for forensic data analysis.


Assuntos
Impressões Digitais de DNA/instrumentação , Linhagem , Grupos Raciais/genética , Alelos , Feminino , Genótipo , Humanos , Masculino , Repetições de Microssatélites , Polimorfismo de Nucleotídeo Único , Reprodutibilidade dos Testes , Método Simples-Cego
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