The impact of diabetes mellitus on blood age estimation using DNA methylation

One of the epigenetic mechanisms used in many areas in recent years is DNA methylation. In forensic studies, DNA methylation can be used for various purposes such as tissue and cell type identification, gender determination, age estimation and distinguishing monozygotic twins. Traditionally, age estimation is done from bones and/or teeth. In recent years, the relationship between DNA methylation and aging has been discovered in epigenetic studies. In this way, age estimation panels specific to different body tissues, which show high accuracy for age estimation, have been developed. In this thesis study, the blood age estimation panel developed by Filoğlu et al. (2024) in the laboratory of Istanbul University-Cerrahpaşa Institute of Forensic Medicine and Forensic Sciences was evaluated in terms of diabetic patients. The panel, which includes 8 CpG regions (ELOVL2, ASPA, TOM1L1, C1orf132, RASSF5, FHL2, CCDC102B and cg07082267), was used to determine methylation profiles in blood samples of 51 diabetic patients using the SNaPshot method and to estimate age. According to the age estimation results, the MAE value was ±5.68 years and the RMSE value was ±6.80 years in diabetic patients. When the model group and the diabetes study group were compared, the deviations determined in the age estimation were higher in diabetic patients as predicted. Consequently, considering the obtained data, the disease history of the suspects should be taken into consideration when estimating age with DNA methylation in forensic cases. It is thought that more comprehensive studies should be conducted in terms of different diseases in which methylation is known to play a role.