Human Epigenetics and Bioinformatics for Forensic Age Estimation

• Applicants: Professorin Dr. Stefanie Ritz; Professor Dr. Wolfgang Wagner
• Subject Area: Pathology
• Term: since 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 314368153

In this time of worldwide migration the estimation of chronological age is an increasingly important task in Forensic Medicine, e.g. for identification of unknown corpses, for analysis of blood traces, and particularly for clarification of the rights of living persons with (allegedly) unknown ages as in the case of unaccompanied refugees. Molecular changes upon aging enable the development of new methods for age estimation. There is a growing perception that aging is associated with highly reproducible epigenetic modifications - especially in the DNA-methylation (DNAm) pattern - which can be used for epigenetic age predictions. This project will explore the possibilities and limits of this approach. In detail, it pursues the following aims: We want to develop a reliable Epigenetic-Aging-Signature based on DNAm at few CpG sites to facilitate higher precision (particularly also for children and juveniles) and applicability for multiple tissues. To this end, we will utilize very large sets of publically available DNAm profiles and combine linear with non-linear mathematical approaches. Predictions will also be correlated with other clinical parameters to estimate deviation due to biological aging. We will establish and validate a cost-effective assay for epigenetic age predictions. Different methods (including pyrosequencing, MassARRAY, and deep sequencing of bisulfite converted DNA) will be systematically compared. Since the usage of buccal swabs enables non-invasive age estimation in livings, the applicability will be further evaluated. Furthermore we will screen for parameters that may interfere with age-predictions - such as ethnical background, infection, diseases affecting growth and development. Last but not least, applicability of epigenetic age predictions will be compared with state of the art approaches for forensic age estimation such as dental status, ossification status of carpals and distal lower arm bones, and aspartic acid racemization analysis of tooth root dentin. We expect that the precision of our epigenetic age-predictions will be in a similar range as of conventional methods and may therefore complement these. This project combines the expertise of epigenetics (group of Wagner) with forensic age predictions (group of Ritz-Timme). It shall provide further insight into epigenetic changes upon aging and provide the basis for a reliable method that meets the needs for forensic age-estimations.

• DFG Programme: Research Grants