Publications by authors named "Ana Margarida Bento"

2 Publications

  • Page 1 of 1

Collaborative EDNAP exercise on the IrisPlex system for DNA-based prediction of human eye colour.

Forensic Sci Int Genet 2014 Jul 21;11:241-51. Epub 2014 Apr 21.

Department of Forensic Molecular Biology, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands. Electronic address:

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.
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http://dx.doi.org/10.1016/j.fsigen.2014.04.006DOI Listing
July 2014

Distribution of Y-chromosomal haplotypes in the Central Portuguese population using 17-STRs.

Forensic Sci Int Genet 2009 Dec 26;4(1):e35-6. Epub 2009 Mar 26.

Forensic Genetic Service, National Institute of Legal Medicine, Centre Branch, 3000-213 Coimbra, Portugal.

17 Y-chromosome STR loci (DYS19, DYS389I, DYS389II, DYS390, DYS456, DYS391, DYS392, DYS393, DYS385 a/b, DYS458, DYS439, DYS635, GATA H4.1, DYS437, DYS438 and DYS448) were determined for 303 unrelated males, living in Central Portugal, using the AmpFlSTR YFiler PCR Amplification kit (Applied Biosystems). A total of 287 different haplotypes were found, 272 being unique. The overall haplotype diversity (HD) was determined as 0.9996, a value similar to other YFiler data sets. Y-STR polymorphisms in Central Portugal population, using YFiler, provide a powerful discrimination tool for routine forensic applications.
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http://dx.doi.org/10.1016/j.fsigen.2009.02.006DOI Listing
December 2009