title: Collaborative EDNAP exercise on the IrisPlex system for DNA-based prediction of human eye colour.
abstract: The IrisPlex system is a DNA-based test system for the prediction of human eye colour from biological samples and consists of a single forensically validated multiplex genotyping assay together with a statistical prediction model that is based on genotypes and phenotypes from thousands of individuals. IrisPlex predicts blue and brown human eye colour with, on average, >94% precision accuracy using six of the currently most eye colour informative single nucleotide polymorphisms (HERC2 rs12913832, OCA2 rs1800407, SLC24A4 rs12896399, SLC45A2 (MATP) rs16891982, TYR rs1393350, and IRF4 rs12203592) according to a previous study, while the accuracy in predicting non-blue and non-brown eye colours is considerably lower. In an effort to vigorously assess the IrisPlex system at the international level, testing was performed by 21 laboratories in the context of a collaborative exercise divided into three tasks and organised by the European DNA Profiling (EDNAP) Group of the International Society of Forensic Genetics (ISFG). Task 1 involved the assessment of 10 blood and saliva samples provided on FTA cards by the organising laboratory together with eye colour phenotypes; 99.4% of the genotypes were correctly reported and 99% of the eye colour phenotypes were correctly predicted. Task 2 involved the assessment of 5 DNA samples extracted by the host laboratory from simulated casework samples, artificially degraded, and provided to the participants in varying DNA concentrations. For this task, 98.7% of the genotypes were correctly determined and 96.2% of eye colour phenotypes were correctly inferred. For Tasks 1 and 2 together, 99.2% (1875) of the 1890 genotypes were correctly generated and of the 15 (0.8%) incorrect genotype calls, only 2 (0.1%) resulted in incorrect eye colour phenotypes. The voluntary Task 3 involved participants choosing their own test subjects for IrisPlex genotyping and eye colour phenotype inference, while eye photographs were provided to the organising laboratory and judged; 96% of the eye colour phenotypes were inferred correctly across 100 samples and 19 laboratories. The high success rates in genotyping and eye colour phenotyping clearly demonstrate the reproducibility and the robustness of the IrisPlex assay as well as the accuracy of the IrisPlex model to predict blue and brown eye colour from DNA. Additionally, this study demonstrates the ease with which the IrisPlex system is implementable and applicable across forensic laboratories around the world with varying pre-existing experiences.
authors.affiliation: Department of Forensic Molecular Biology, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands.
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Chaitanya
authors.affiliation: Department of Forensic Molecular Biology, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands.
authors.forename: Susan
authors.initials: S
authors.lastname: Walsh
authors.affiliation: Section of Forensic Genetics, Department of Forensic Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jeppe Dyrberg
authors.initials: JD
authors.lastname: Andersen
authors.affiliation: Swedish National Laboratory of Forensic Science (SKL), Linköping, Sweden.
authors.forename: Ricky
authors.initials: R
authors.lastname: Ansell
authors.affiliation: Forensic Services Department, Victoria Police, Macleod, Victoria, Australia.
authors.forename: Kaye
authors.initials: K
authors.lastname: Ballantyne
authors.affiliation: Department of Forensic and Analytical Science, School of Biomedical Sciences, King's College London, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Ballard
authors.affiliation: Kriminaltechnik, Bundeskriminalamt, Wiesbaden, Germany.
authors.forename: Regine
authors.initials: R
authors.lastname: Banemann
authors.affiliation: Institute of Legal Medicine, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Christiane Maria
authors.initials: CM
authors.lastname: Bauer
authors.affiliation: Serviço de Genética e Biologia Forense, Delegação do Centro, Instituto Nacional de Medicina Legal, Coimbra, Portugal.
authors.forename: Ana Margarida
authors.initials: AM
authors.lastname: Bento
authors.affiliation: Forensic Genetics Laboratory, Institute of Legal Medicine, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Brisighelli
authors.affiliation: Department of Forensic Genetics, Institute of Criminalistics, Prague, Czech Republic.
authors.forename: Tomas
authors.initials: T
authors.lastname: Capal
authors.affiliation: Department of Human Biological Traces, Netherlands Forensic Institute, The Hague, The Netherlands.
authors.forename: Lindy
authors.initials: L
authors.lastname: Clarisse
authors.affiliation: Institute of Legal Medicine, Faculty of Medicine, University of Cologne, Cologne, Germany.
authors.forename: Theresa E
authors.initials: TE
authors.lastname: Gross
authors.affiliation: Institute of Legal Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Cordula
authors.initials: C
authors.lastname: Haas
authors.affiliation: Department of Forensic Biology, Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Per
authors.initials: P
authors.lastname: Hoff-Olsen
authors.affiliation: Laboratoire d'Anthropologie Moléculaire, Université de Strasbourg, Institut de Médecine Légale, Strasbourg, France.
authors.forename: Clémence
authors.initials: C
authors.lastname: Hollard
authors.affiliation: Laboratoire d'Anthropologie Moléculaire, Université de Strasbourg, Institut de Médecine Légale, Strasbourg, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Keyser
authors.affiliation: Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Kiesler
authors.affiliation: Department of Forensic Biology, Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Priscila
authors.initials: P
authors.lastname: Kohler
authors.affiliation: Section of Forensic Genetics, Institute of Forensic Research, Kraków, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Kupiec
authors.affiliation: School of Biological Sciences, Flinders University, Adelaide, South Australia, Australia.
authors.forename: Adrian
authors.initials: A
authors.lastname: Linacre
authors.affiliation: Kriminaltechnik, Bundeskriminalamt, Wiesbaden, Germany.
authors.forename: Anglika
authors.initials: A
authors.lastname: Minawi
authors.affiliation: Section of Forensic Genetics, Department of Forensic Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Niels
authors.initials: N
authors.lastname: Morling
authors.affiliation: Department of Forensic Genetics and Forensic Toxicology, National Board of Forensic Medicine, Linköping, Sweden.
authors.forename: Helena
authors.initials: H
authors.lastname: Nilsson
authors.affiliation: Swedish National Laboratory of Forensic Science (SKL), Linköping, Sweden.
authors.forename: Lina
authors.initials: L
authors.lastname: Norén
authors.affiliation: School of Biological Sciences, Flinders University, Adelaide, South Australia, Australia.
authors.forename: Renée
authors.initials: R
authors.lastname: Ottens
authors.affiliation: Department of Forensic Medicine, Hjelt Institute, University of Helsinki, Helsinki, Finland.
authors.forename: Jukka U
authors.initials: JU
authors.lastname: Palo
authors.affiliation: Institute of Legal Medicine, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Walther
authors.initials: W
authors.lastname: Parson
authors.affiliation: Forensic Genetics Laboratory, Institute of Legal Medicine, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Vincenzo L
authors.initials: VL
authors.lastname: Pascali
authors.affiliation: Forensic Genetics Unit, Institute of Legal Medicine, University of Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: Chris
authors.initials: C
authors.lastname: Phillips
authors.affiliation: Serviço de Genética e Biologia Forense, Delegação do Centro, Instituto Nacional de Medicina Legal, Coimbra, Portugal.
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Porto
authors.affiliation: Department of Forensic Medicine, Hjelt Institute, University of Helsinki, Helsinki, Finland; Institute of Applied Genetics, Department of Forensic and Investigative Genetics, University of North Texas Health Science Center, Fort Worth, TX, USA.
authors.forename: Antti
authors.initials: A
authors.lastname: Sajantila
authors.affiliation: Institute of Legal Medicine, Faculty of Medicine, University of Cologne, Cologne, Germany.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Schneider
authors.affiliation: Department of Human Biological Traces, Netherlands Forensic Institute, The Hague, The Netherlands.
authors.forename: Titia
authors.initials: T
authors.lastname: Sijen
authors.affiliation: Forensic Genetics Unit, Institute of Legal Medicine, University of Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: Jens
authors.initials: J
authors.lastname: Söchtig
authors.affiliation: Department of Forensic and Analytical Science, School of Biomedical Sciences, King's College London, United Kingdom.
authors.forename: Denise
authors.initials: D
authors.lastname: Syndercombe-Court
authors.affiliation: Department of Forensic Genetics and Forensic Toxicology, National Board of Forensic Medicine, Linköping, Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Tillmar
authors.affiliation: Institute of Forensic Science, Ministry of the Interior, Department of Biology and DNA Analysis, Slovenská Lupca, Slovakia.
authors.forename: Martina
authors.initials: M
authors.lastname: Turanska
authors.affiliation: Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Vallone
authors.affiliation: Institute of Forensic Science, Ministry of the Interior, Department of Biology and DNA Analysis, Slovenská Lupca, Slovakia.
authors.forename: Lívia
authors.initials: L
authors.lastname: Zatkalíková
authors.affiliation: Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Prague, Czech Republic; Institute of Forensic Medicine and Toxicology, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
authors.forename: Anastassiya
authors.initials: A
authors.lastname: Zidkova
authors.affiliation: Section of Forensic Genetics, Institute of Forensic Research, Kraków, Poland; Department of Genetics and Evolution, Institute of Zoology, Jagiellonian University, Kraków, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Branicki
authors.affiliation: Department of Forensic Molecular Biology, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands. Electronic address: m.kayser@erasmusmc.nl.
authors.forename: Manfred
authors.initials: M
authors.lastname: Kayser
mesh_terms: D004247:DNA / Q000235:genetics*; D005127:Eye Color / Q000235:genetics*; D006801:Humans
chemical_list: D004247:DNA
keywords: EDNAP; Eye colour prediction; FDP; Forensic DNA phenotyping; ISFG; IrisPlex