Abstract
The IrisPlex system consists of a highly sensitive multiplex genotyping assay together
with a statistical prediction model, providing users with the ability to predict blue
and brown human eye colour from DNA samples with over 90% precision. This ‘DNA intelligence’
system is expected to aid police investigations by providing phenotypic information
on unknown individuals when conventional DNA profiling is not informative. Falling
within the new area of forensic DNA phenotyping, this paper describes the developmental
validation of the IrisPlex assay following the Scientific Working Group on DNA Analysis
Methods (SWGDAM) guidelines for the application of DNA-based eye colour prediction
to forensic casework. The IrisPlex assay produces complete SNP genotypes with only
31 pg of DNA, approximately six human diploid cell equivalents, and is therefore more
sensitive than commercial STR kits currently used in forensics. Species testing revealed
human and primate specificity for a complete SNP profile. The assay is capable of
producing accurate results from simulated casework samples such as blood, semen, saliva,
hair, and trace DNA samples, including extremely low quantity samples. Due to its
design, it can also produce full profiles with highly degraded samples often found
in forensic casework. Concordance testing between three independent laboratories displayed
reproducible results of consistent levels on varying types of simulated casework samples.
With such high levels of sensitivity, specificity, consistency and reliability, this
genotyping assay, as a core part of the IrisPlex system, operates in accordance with
SWGDAM guidelines. Furthermore, as we demonstrated previously, the IrisPlex eye colour
prediction system provides reliable results without the need for knowledge on the
bio-geographic ancestry of the sample donor. Hence, the IrisPlex system, with its
model-based prediction probability estimation of blue and brown human eye colour,
represents a useful tool for immediate application in accredited forensic laboratories,
to be used for forensic intelligence in tracing unknown individuals from crime scene
samples.
Keywords
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to Forensic Science International: GeneticsAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- DNA-based prediction of human externally visible characteristics in forensics: motivations, scientific challenges, and ethical considerations.Forensic Sci. Int. Genet. 2009; 3: 154-161
- Eye color and the prediction of complex phenotypes from genotypes.Curr. Biol. 2009; 19: R192-R193
- Genetic determinants of hair, eye and skin pigmentation in Europeans.Nat. Genet. 2007; 39: 1443-1452
- Human eye colour and HERC2, OCA2 and MATP.Forensic Sci. Int. Genet. 2010; https://doi.org/10.1016/j.fsigen.2009.12.004
- IrisPlex: a sensitive DNA tool for accurate prediction of blue and brown eye colour in the absence of ancestry information.Forensic Sci .Int. Genet. 2010; https://doi.org/10.1016/j.fsigen.2010.02.004
- Scientific Working Group on DNA analysis methods, revised validation guidelines.Forensic Sci. Commun. 2004; 6
- Development of Y-chromosomal microsatellite markers for nonhuman primates.Mol. Ecol. 2004; 13: 2921-2930
- A multiplex assay with 52 single nucleotide polymorphisms for human identification.Electrophoresis. 2006; 27: 1713-1724
- SNP typing of FTA card samples with low amounts of DNA after DNA extraction using a Qiagen BioRobot® EZ1 Workstation.Forensic Sci. Int. Gene. Suppl. 2009; 2: 83-84
- Development and validation of the AmpFlSTR MiniFiler PCR AmplificationKit: a MiniSTR multiplex for the analysis of degraded and/or PCR inhibited DNA.J. Forensic Sci. 2008; 53: 838-852
- Validation of a single nucleotide polymorphism (SNP) typing assay with 49 SNPs for forensic genetic testing in a laboratory accredited according to the ISO 17025 standard.Forensic Sci. Int. Genet. 2009; 4: 34-42
- SNPs in forensic genetics: a review on SNP typing methodologies.Forensic Sci. Int. 2005; 154: 181-194
- Population differences of two coding SNPs in pigentation-related genes SLC24A5 and SLC45A2.Int. J. Legal Med. 2007; 121: 36-39
- Brief communication: blue eyes in lemurs and humans: same phenotype, different genetic mechanism.Am. J. Phys. Anthropol. 2009; 139: 269-273
- New reagent for protein-DNA contacts footprinting.Nucleos. Nucl. Nucleic Acids. 2003; 22: 1587-1589
- An Introduction to Anthropology.Macmillan, New York1965
Article info
Publication history
Published online: October 15, 2010
Accepted:
September 15,
2010
Received in revised form:
September 1,
2010
Received:
July 21,
2010
Identification
Copyright
© 2010 Elsevier Ireland Ltd. Published by Elsevier Inc. All rights reserved.
