2
|
Gill P, Benschop C, Buckleton J, Bleka Ø, Taylor D. A Review of Probabilistic Genotyping Systems: EuroForMix, DNAStatistX and STRmix™. Genes (Basel) 2021; 12:1559. [PMID: 34680954 PMCID: PMC8535381 DOI: 10.3390/genes12101559] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/24/2021] [Accepted: 09/28/2021] [Indexed: 11/24/2022] Open
Abstract
Probabilistic genotyping has become widespread. EuroForMix and DNAStatistX are both based upon maximum likelihood estimation using a γ model, whereas STRmix™ is a Bayesian approach that specifies prior distributions on the unknown model parameters. A general overview is provided of the historical development of probabilistic genotyping. Some general principles of interpretation are described, including: the application to investigative vs. evaluative reporting; detection of contamination events; inter and intra laboratory studies; numbers of contributors; proposition setting and validation of software and its performance. This is followed by details of the evolution, utility, practice and adoption of the software discussed.
Collapse
Affiliation(s)
- Peter Gill
- Forensic Genetics Research Group, Department of Forensic Sciences, Oslo University Hospital, 0372 Oslo, Norway;
- Department of Forensic Medicine, Institute of Clinical Medicine, University of Oslo, 0315 Oslo, Norway
| | - Corina Benschop
- Division of Biological Traces, Netherlands Forensic Institute, P.O. Box 24044, 2490 AA The Hague, The Netherlands;
| | - John Buckleton
- Department of Statistics, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand;
- Institute of Environmental Science and Research Limited, Private Bag 92021, Auckland 1142, New Zealand
| | - Øyvind Bleka
- Forensic Genetics Research Group, Department of Forensic Sciences, Oslo University Hospital, 0372 Oslo, Norway;
| | - Duncan Taylor
- Forensic Science SA, GPO Box 2790, Adelaide, SA 5001, Australia;
- School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
| |
Collapse
|
3
|
Benschop CCG, van der Gaag KJ, de Vreede J, Backx AJ, de Leeuw RH, Zuñiga S, Hoogenboom J, de Knijff P, Sijen T. Application of a probabilistic genotyping software to MPS mixture STR data is supported by similar trends in LRs compared with CE data. Forensic Sci Int Genet 2021; 52:102489. [PMID: 33677249 DOI: 10.1016/j.fsigen.2021.102489] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 02/03/2021] [Accepted: 02/24/2021] [Indexed: 02/06/2023]
Abstract
The interpretation of short tandem repeat (STR) profiles can be challenging when, for example, alleles are masked due to allele sharing among contributors and/or when they are subject to drop-out, for instance from sample degradation. Mixture interpretation can be improved by increasing the number of STRs and/or loci with a higher discriminatory power. Both capillary electrophoresis (CE, 6-dye) and massively parallel sequencing (MPS) provide a platform for analysing relatively large numbers of autosomal STRs. In addition, MPS enables distinguishing between sequence variants, resulting in enlarged discriminatory power. Also, MPS allows for small amplicon sizes for all loci as spacing is not an issue, which is beneficial with degraded DNA. Altogether, MPS has the potential to increase the weights of evidence for true contributors to (complex) DNA profiles. In this study, likelihood ratio (LR) calculations were performed using STR profiles obtained with two different MPS systems and analysed using different settings: 1) MPS PowerSeq™ Auto System profiles analysed using FDSTools equipped with optimized settings such as noise correction, 2) ForenSeq™ DNA Signature Prep Kit profiles analysed using the default settings in the Universal Analysis Software (UAS), and 3) ForenSeq™ DNA Signature Prep Kit profiles analysed using FDSTools empirically adapted to cope with one-directional reads and provisional, basic settings. The LR calculations used genotyping data for two- to four-person mixtures varying for mixture proportion, level of drop-out and allele sharing and were generated with the continuous model EuroForMix. The LR results for the over 2000 sets of propositions were affected by the variation for the number of markers and analysis settings used in the three approaches. Nevertheless, trends for true and non-contributors, effects of replicates, assigned number of contributors, and model validation results were comparable for the three MPS approaches and alike the trends known for CE data. Based on this analogy, we regard the probabilistic interpretation of MPS STR data fit for forensic DNA casework. In addition, guidelines were derived on when to apply LR calculations to MPS autosomal STR data and report the corresponding results.
Collapse
Affiliation(s)
- Corina C G Benschop
- Division of Biological Traces, Netherlands Forensic Institute, The Hague, The Netherlands.
| | | | - Jennifer de Vreede
- Division of Biological Traces, Netherlands Forensic Institute, The Hague, The Netherlands.
| | - Anouk J Backx
- Division of Biological Traces, Netherlands Forensic Institute, The Hague, The Netherlands.
| | - Rick H de Leeuw
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
| | - Sofia Zuñiga
- Division of Biological Traces, Netherlands Forensic Institute, The Hague, The Netherlands.
| | - Jerry Hoogenboom
- Division of Biological Traces, Netherlands Forensic Institute, The Hague, The Netherlands.
| | - Peter de Knijff
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
| | - Titia Sijen
- Division of Biological Traces, Netherlands Forensic Institute, The Hague, The Netherlands; University of Amsterdam, Swammerdam Institute for Life Sciences, Amsterdam, The Netherlands.
| |
Collapse
|
4
|
Sheth N, Swaminathan H, Gonzalez AJ, Duffy KR, Grgicak CM. Towards developing forensically relevant single-cell pipelines by incorporating direct-to-PCR extraction: compatibility, signal quality, and allele detection. Int J Legal Med 2021; 135:727-738. [PMID: 33484330 DOI: 10.1007/s00414-021-02503-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 01/04/2021] [Indexed: 12/24/2022]
Abstract
Current analysis of forensic DNA stains relies on the probabilistic interpretation of bulk-processed samples that represent mixed profiles consisting of an unknown number of potentially partial representations of each contributor. Single-cell methods, in contrast, offer a solution to the forensic DNA mixture problem by incorporating a step that separates cells before extraction. A forensically relevant single-cell pipeline relies on efficient direct-to-PCR extractions that are compatible with standard downstream forensic reagents. Here we demonstrate the feasibility of implementing single-cell pipelines into the forensic process by exploring four metrics of electropherogram (EPG) signal quality-i.e., allele detection rates, peak heights, peak height ratios, and peak height balance across low- to high-molecular-weight short tandem repeat (STR) markers-obtained with four direct-to-PCR extraction treatments and a common post-PCR laboratory procedure. Each treatment was used to extract DNA from 102 single buccal cells, whereupon the amplification reagents were immediately added to the tube and the DNA was amplified/injected using post-PCR conditions known to elicit a limit of detection (LoD) of one DNA molecule. The results show that most cells, regardless of extraction treatment, rendered EPGs with at least a 50% true positive allele detection rate and that allele drop-out was not cell independent. Statistical tests demonstrated that extraction treatments significantly impacted all metrics of EPG quality, where the Arcturus® PicoPure™ extraction method resulted in the lowest median allele drop-out rate, highest median average peak height, highest median average peak height ratio, and least negative median values of EPG sloping for GlobalFiler™ STR loci amplified at half volume. We, therefore, conclude the feasibility of implementing single-cell pipelines for casework purposes and demonstrate that inferential systems assuming cell independence will not be appropriate in the probabilistic interpretation of a collection of single-cell EPGs.
Collapse
Affiliation(s)
- Nidhi Sheth
- Center for Computational and Integrative Biology, Rutgers University, Camden, NJ, 08102, USA
| | - Harish Swaminathan
- Biomedical Forensic Sciences Program, Boston University School of Medicine, Boston, MA, 02118, USA
| | - Amanda J Gonzalez
- Department of Chemistry, Rutgers University, 315 Penn Street R306C, Camden, NJ, 08102, USA
| | - Ken R Duffy
- Hamilton Institute, Maynooth University, Maynooth, Ireland
| | - Catherine M Grgicak
- Center for Computational and Integrative Biology, Rutgers University, Camden, NJ, 08102, USA.
- Biomedical Forensic Sciences Program, Boston University School of Medicine, Boston, MA, 02118, USA.
- Department of Chemistry, Rutgers University, 315 Penn Street R306C, Camden, NJ, 08102, USA.
| |
Collapse
|
11
|
Toscanini U, Gusmão L, Álava Narváez MC, Álvarez JC, Baldassarri L, Barbaro A, Berardi G, Betancor Hernández E, Camargo M, Carreras-Carbonell J, Castro J, Costa SC, Coufalova P, Domínguez V, Fagundes de Carvalho E, Ferreira STG, Furfuro S, García O, Goios A, González R, de la Vega AG, Gorostiza A, Hernández A, Jiménez Moreno S, Lareu MV, León Almagro A, Marino M, Martínez G, Miozzo MC, Modesti NM, Onofri V, Pagano S, Pardo Arias B, Pedrosa S, Penacino GA, Pontes ML, Porto MJ, Puente-Prieto J, Pérez RR, Ribeiro T, Rodríguez Cardozo B, Rodríguez Lesmes YM, Sala A, Santiago B, Saragoni VG, Serrano A, Streitenberger ER, Torres Morales MA, Vannelli Rey SA, Velázquez Miranda M, Whittle MR, Fernández K, Salas A. Analysis of uni and bi-parental markers in mixture samples: Lessons from the 22nd GHEP-ISFG Intercomparison Exercise. Forensic Sci Int Genet 2016; 25:63-72. [PMID: 27500650 DOI: 10.1016/j.fsigen.2016.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 07/14/2016] [Accepted: 07/17/2016] [Indexed: 10/21/2022]
Abstract
Since 1992, the Spanish and Portuguese-Speaking Working Group of the ISFG (GHEP-ISFG) has been organizing annual Intercomparison Exercises (IEs) coordinated by the Quality Service at the National Institute of Toxicology and Forensic Sciences (INTCF) from Madrid, aiming to provide proficiency tests for forensic DNA laboratories. Each annual exercise comprises a Basic (recently accredited under ISO/IEC 17043: 2010) and an Advanced Level, both including a kinship and a forensic module. Here, we show the results for both autosomal and sex-chromosomal STRs, and for mitochondrial DNA (mtDNA) in two samples included in the forensic modules, namely a mixture 2:1 (v/v) saliva/blood (M4) and a mixture 4:1 (v/v) saliva/semen (M8) out of the five items provided in the 2014 GHEP-ISFG IE. Discrepancies, other than typos or nomenclature errors (over the total allele calls), represented 6.5% (M4) and 4.7% (M8) for autosomal STRs, 15.4% (M4) and 7.8% (M8) for X-STRs, and 1.2% (M4) and 0.0% (M8) for Y-STRs. Drop-out and drop-in alleles were the main cause of errors, with laboratories using different criteria regarding inclusion of minor peaks and stutter bands. Commonly used commercial kits yielded different results for a micro-variant detected at locus D12S391. In addition, the analysis of electropherograms revealed that the proportions of the contributors detected in the mixtures varied among the participants. In regards to mtDNA analysis, besides important discrepancies in reporting heteroplasmies, there was no agreement for the results of sample M4. Thus, while some laboratories documented a single control region haplotype, a few reported unexpected profiles (suggesting contamination problems). For M8, most laboratories detected only the haplotype corresponding to the saliva. Although the GHEP-ISFG has already a large experience in IEs, the present multi-centric study revealed challenges that still exist related to DNA mixtures interpretation. Overall, the results emphasize the need for further research and training actions in order to improve the analysis of mixtures among the forensic practitioners.
Collapse
Affiliation(s)
- U Toscanini
- PRICAI-Fundación Favaloro, Buenos Aires, Argentina.
| | - L Gusmão
- DNA Diagnostic Laboratory (LDD), State University of Rio de Janeiro (UERJ), Rio de Janeiro, Brazil; IPATIMUP (Institute of Pathology and Molecular Immunology from de University of Porto), Porto, Portugal; I3s (Instituto de Investigação e Inovação em Saúde, Universidade do Porto), Porto, Portugal
| | - M C Álava Narváez
- Laboratorio de Genética Regional Bogotá del Instituto Nacional de Medicina Legal y Ciencias Forenses., Bogotá, Colombia
| | - J C Álvarez
- Lab. de Identificación Genética. Depto. de Medicina Legal, Toxicología y Antropología Física. Facultad de Medicina. Universidad de Granada, Granada, Spain
| | - L Baldassarri
- Institute of Public Sanity Section of Legal Medicine Catholic University of Sacred Heart, Rome, Rome, Italy
| | - A Barbaro
- Studio Indagini Mediche E Forensi (SIMEF), Reggio Calabria, Italy
| | - G Berardi
- PRICAI-Fundación Favaloro, Buenos Aires, Argentina
| | - E Betancor Hernández
- Laboratorio Genética Forense, Instituto de Medicina Legal de Las Palmas, ULPG., Las Palmas, Spain
| | - M Camargo
- Laboratorio de Genética Regional Suroccidente del Instituto Nacional de Medicina Legal y Ciencias Forenses., Cali, Colombia
| | - J Carreras-Carbonell
- Policia de la Generalitat - Mossos d'Esquadra, Divisió de Policia Científica, Unitat Central del Laboratori Biològic, Sabadell, Barcelona, Spain
| | - J Castro
- Genética Forense, Unidad Criminalistica Contra la Vulneración de Derechos Fundamentales, Ministerio Público, Venezuela
| | - S C Costa
- Laboratório de Polícia Científica da Polícia Judiciária, Lisbon, Portugal
| | - P Coufalova
- Institute of Criminalistics Prague, Prague, Czech Republic
| | - V Domínguez
- Lab. Biológico de la Dirección Nacional de Policía Científica, Montevideo, Uruguay
| | - E Fagundes de Carvalho
- DNA Diagnostic Laboratory (LDD), State University of Rio de Janeiro (UERJ), Rio de Janeiro, Brazil
| | - S T G Ferreira
- Instituto de Pesquisa de DNA Forense, IPDNA, Polícia Civil do Distrito Federal, PCDF, Brasília, Brazil, and Secretaria Nacional de Segurança Pública do Ministério da Justiça, SENASP/MJ, Brasília, Brazil
| | - S Furfuro
- Laboratorio de Análisis de ADN- Facultad de Ciencias Médicas- Universidad Nacional de Cuyo, Mendoza, Argentina
| | - O García
- Forensic Science Unit, Forensic Genetics Section, Basque Country Police-Ertzaintza, Erandio, Bizkaia, Spain
| | - A Goios
- IPATIMUP (Institute of Pathology and Molecular Immunology from de University of Porto), Porto, Portugal; I3s (Instituto de Investigação e Inovação em Saúde, Universidade do Porto), Porto, Portugal
| | - R González
- Registro Nacional de ADN, Chile, Santiago de Chile, Chile
| | | | | | - A Hernández
- Instituto Nacional de Toxicología y Ciencias Forenses, Delegación en Canarias, Santa Cruz de Tenerife, Spain
| | - S Jiménez Moreno
- Laboratorio de Biología Forense. Dpto Patología y Cirugía. Universidad Miguel Hernández, Elche, Alicante, Spain
| | - M V Lareu
- Unidade de Xenética, Departamento de Anatomía Patolóxica e Ciencias Forenses, Instituto de Ciencias Forenses, Facultade de Medicina, Universidade de Santiago de Compostela, and GenPop Research Group, Instituto de Investigaciones Sanitarias (IDIS), Hospital Clínico Universitario de Santiago, Galicia, Spain
| | - A León Almagro
- Comisaría General de Policía Científica - Laboratorio de ADN, Madrid, Spain
| | - M Marino
- Laboratorio de Genética Forense, Poder Judicial de Mendoza, Mendoza, Argentina
| | - G Martínez
- Servicio de Genética Forense, Superior Tribunal de Justicia de Entre Ríos, Paraná, Argentina
| | - M C Miozzo
- Laboratorio Regional de Genética Forense del NOA - Departamento Médico - Poder Judicial de Jujuy, Jujuy, Argentina
| | - N M Modesti
- Instituto de Genética Forense. Poder Judicial de Córdoba, Córdoba, Argentina
| | - V Onofri
- Universita' Politecnica Delle Marche, DSBSP, Section of Legal Medicine, Ancona, Italy
| | | | - B Pardo Arias
- Instituto Nacional de Toxicología y Ciencias Forenses, Departamento de Sevilla, Sevilla, Spain
| | | | - G A Penacino
- Unidad de Analisis de ADN, Colegio Oficial de Farmaceuticos y Bioquímicos, Buenos Aires, Argentina
| | - M L Pontes
- Serviço de Genética e Biologia Forenses, Instituto Nacional de Medicina Legal e Ciências Forenses, I.P. - Delegação do Norte, Porto, Portugal
| | - M J Porto
- Serviço de Genética e Biologia Forenses, Instituto Nacional de Medicina Legal e Ciências Forenses, I.P., Coimbra, Portugal
| | - J Puente-Prieto
- LabGenetics. Laboratorio de Genética Clínica S.L., Madrid, Spain
| | | | - T Ribeiro
- Serviço de Genética e Biologia Forenses, Instituto Nacional de Medicina Legal e Ciências Forenses, I.P.-Delegação Sul, Lisbon, Portugal
| | | | - Y M Rodríguez Lesmes
- Laboratorio de Biología y Genética Regional Noroccidente del Instituto Nacional de Medicina Legal y Ciencias Forenses., Medellín, Colombia
| | - A Sala
- Servicio de Huellas Digitales Genéticas-Fac. Farmacia y Bioquímica-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - B Santiago
- Instituto Nacional de Toxicología y Ciencias Forenses, Departamento de Madrid. Servicio de Biología., Madrid, Spain
| | - V G Saragoni
- Unidad de Genética Forense, Servicio Médico Legal, Santiago, Chile
| | - A Serrano
- Instituto Nacional de Toxicología y Ciencias Forenses, Departamento de Barcelona, Barcelona, Spain
| | | | | | - S A Vannelli Rey
- Laboratorio Regional Patagonia Norte de Genética Forense - Poder Judicial de Río Negro, Bariloche, Argentina
| | | | - M R Whittle
- Genomic Engenharia Molecular, Sao Paulo, Brazil
| | - K Fernández
- Instituto Nacional de Toxicología y Ciencias Forenses, Departamento de Madrid. Servicio de Biología., Madrid, Spain
| | - A Salas
- Unidade de Xenética, Departamento de Anatomía Patolóxica e Ciencias Forenses, Instituto de Ciencias Forenses, Facultade de Medicina, Universidade de Santiago de Compostela, and GenPop Research Group, Instituto de Investigaciones Sanitarias (IDIS), Hospital Clínico Universitario de Santiago, Galicia, Spain
| |
Collapse
|