Department of Forensic Molecular Biology, Erasmus MC University Medical Centre, Dr Molewaterplein 50, 3015 GE Rotterdam, Zuid-Holland, The Netherlands.
Forensic Sci Int Genet. 2011 Nov;5(5):464-71. doi: 10.1016/j.fsigen.2010.09.008. Epub 2010 Oct 14.
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 31pg 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.
虹膜plex 系统由一个高度敏感的多重基因分型检测和一个统计预测模型组成，为用户提供了从 DNA 样本中预测蓝眼睛和褐色眼睛的能力，准确率超过 90%。这种“DNA 智能”系统有望通过提供未知个体的表型信息，在常规 DNA 分析不提供信息时，协助警方调查。作为法医 DNA 表型分析的新领域，本文描述了虹膜 plex 检测的开发验证，遵循了科学工作组关于 DNA 分析方法（SWGDAM）的指导方针，将基于 DNA 的眼睛颜色预测应用于法医工作。虹膜 plex 检测仅用 31pg 的 DNA（大约 6 个人类二倍体细胞当量）即可生成完整的 SNP 基因型，因此比目前法医中使用的商业 STR 试剂盒更灵敏。物种测试显示完整 SNP 图谱具有人类和灵长类特异性。该检测能够从模拟案件样本（如血液、精液、唾液、头发和痕量 DNA 样本）中得出准确的结果，包括非常低数量的样本。由于其设计，它还可以生成完整的图谱，包括在法医案件工作中经常发现的高度降解的样本。三个独立实验室的一致性测试显示了不同类型模拟案件样本的一致水平的可重复结果。由于具有如此高的灵敏度、特异性、一致性和可靠性，这种基因分型检测作为虹膜 plex 系统的核心部分，符合 SWGDAM 指导方针。此外，正如我们之前所证明的，虹膜 plex 眼睛颜色预测系统提供可靠的结果，而不需要了解样本捐赠者的生物地理起源。因此，虹膜 plex 系统及其基于模型的蓝色和褐色人类眼睛颜色预测概率估计，代表了一种在经认可的法医实验室中立即应用的有用工具，可用于从犯罪现场样本中追踪未知个体的法医情报。
