Age estimation of unidentified bodies is important in forensic medicine and crime scenes. There is accumulating evidence that DNA methylation in the human genome isolated from body fluids changes with age. Most of the data have been obtained by pyrosequencing. In the forensic field, a simple, quick, and economical method is required to evaluate the age of various types of samples. In this study, an age estimation method based on methylation levels of DNA extracted from teeth using real-time methylation-specific PCR (MSP) was developed. The CpG island in the upstream region of ELOVL2, which is known as a validated biomarker in blood samples, was selected as a target site. The CpG methylation levels highly correlated with age (r = 0.843, n = 29). Age-related increase in DNA methylation levels was not affected by sex differences. In addition, the simple regression model based on methylation status of the CpG island exhibited moderate accuracy with a mean absolute deviation between chronological age and predicted age of 8.94 years. The results imply that real-time MSP can be a new tool to perform age prediction of unidentified bodies in forensic scenes.

在法医和犯罪现场中，身份不明物体的年龄估计很重要。有越来越多的证据表明，从体液中分离出来的人类基因组中的DNA甲基化会随着年龄而变化。大多数数据是通过焦磷酸测序获得的。在法医领域，需要一种简单，快速且经济的方法来评估各种类型的样本的年龄。在这项研究中，开发了一种基于年龄的估计方法，该方法基于使用实时甲基化特异性PCR（MSP）从牙齿中提取的DNA的甲基化水平。选择ELOVL2上游区域中的CpG岛作为靶点，该岛被称为血液样本中经过验证的生物标记。CpG甲基化水平与年龄高度相关（r = 0.843，n= 29）。年龄相关的DNA甲基化水平增加不受性别差异的影响。此外，基于CpG岛甲基化状态的简单回归模型显示出适度的准确性，并且在时间年龄和预测年龄之间的平均绝对偏差为8.94岁。结果表明，实时MSP可以成为执行法医场景中身份不明物体的年龄预测的新工具。