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IrisPlex: A Sensitive DNA Tool for Accurate Prediction of Blue and Brown Eye Colour in the Absence of Ancestry Information

NCJ Number
234610
Journal
Forensic Science International: Genetics Volume: 5 Issue: 3 Dated: June 2011 Pages: 170-180
Author(s)
Susan Walsh; Fan Liu; Kaye N. Ballantyne; Mannis van Oven; Oscar Lao; Manfred Kayser
Date Published
June 2011
Length
11 pages
Annotation
This article describes IrisPlex, a DNA tool used for predicting blue and brown eye color in forensic applications that lack ancestry information, and presents preliminary test results of the tool.
Abstract
The IrisPlex is a highly sensitive, robust DNA tool that allows forensic experts to accurately predict blue and brown eye color when conventional profiling provides DNA of limited quantity and quality. The system is based on the six currently most eye color-informative single nucleotide polymorphisms (SNPs) and is designed to allow prediction of blue and brown eye color with high levels of accuracy, is sensitive enough to allow successful analyses of picogram amounts of DNA, is designed to cater for degraded DNA, and is based on a genotyping technology that relies on equipment in wide use in the forensic community. In a preliminary test, the tool displayed high levels of genotyping sensitivity with complete profiles generated from as little as 31pg of DNA, or approximately six human diploid cell equivalents. The article also presents a prediction model that is able to correctly classify an individual's eye color through probability estimation based solely on DNA data. DNA data were obtained from 40 individuals from various geographic locations for testing the accuracy of IrisPlex and the predictive ability of the model. The results of these tests were compared with known test results regarding worldwide allele distribution of the six SNPs, and the findings indicate that the tool and the model perform reliably in the absence of prior ancestry information. Table, figures, appendix, and references