DNA-Based Eye Colour Prediction Across Europe with the IrisPlex System

• NCJ Number: 239320
• Journal: Forensic Science International: Genetics Volume: 6 Issue: 3 Dated: May 2012 Pages: 330-340
• Author(s): Susan Walsh; Andreas Wollstein; Fan Liu; Usha Chakravarthy; Mati Rahu; Johan H. Seland; Gisele Soubrane; Laura Tomazzoli; Fotis Topouzis; Johannes R. Vingerling; Jesus Vioque; Astrid E. Fletcher; Kaye N. Ballantyne; Manfred Kayser
• Date Published: May 2012
• Length: 11 pages
• Publication Format: Article
• Publication Type: Research (Applied/Empirical)
• Language: English
• Country: Ireland

Annotation

This study validated the IrisPlex prediction model by extending the initially described model towards genotype and phenotype data from multiple European populations.

Abstract

For the purpose of DNA-based eye color prediction, researchers in the current study previously developed the IrisPlex system consisting of a multiplex genotyping assay and a prediction model based on genotype and phenotype data from 3,804 Dutch Europeans. Recently, the researchers performed a forensic developmental validation study of the highly sensitive IrisPlex assay, which currently represents the only validated tool available for DNA-based prediction of eye color in forensic applications. The current study performed IrisPlex analysis on 3,840 individuals from seven sites across Europe as part of the European Eye (EUREYE) study for which DNA and high-resolution eye images were available. The accuracy rate of correctly predicting an individual's eye color as being blue or brown, above the empirically established probability threshold of 0.7, was on average 94 percent across all seven European populations, ranging from 91 percent to 98 percent, despite the large variation in eye color frequencies between the populations. The overall prediction accuracies expressed by the area under the receiver characteristic operating curves (AUC) were 0.96 for blue and 0.96 for brown eyes, which is considerably higher than those established before. The IrisPlex prediction model parameters generated from this multi-population European dataset, and thus its prediction capabilities, were highly comparable to those previously established. Therefore, the increased information regarding eye color phenotype and genotype distributions across Europe, and the system's ability to provide eye color predictions across Europe accurately, both highlight additional evidence for the utility of the IrisPlex system in forensic casework. (Published Abstract)