Kondo Masahiro, Aboshi Hirofumi, Yoshikawa Masaaki, Ogata Ayano, Murayama Ryosuke, Takei Masami, Aizawa Shin
Department of Legal Medicine, Nihon University School of Dentistry.
Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine.
J Oral Sci. 2020 Dec 23;63(1):54-58. doi: 10.2334/josnusd.20-0138. Epub 2020 Dec 7.
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.
在法医学和犯罪现场，对身份不明尸体进行年龄估计至关重要。越来越多的证据表明，从体液中分离出的人类基因组中的DNA甲基化会随着年龄的增长而变化。大部分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类样本的年龄。在本研究中，开发了一种基于使用实时甲基化特异性PCR（MSP）从牙齿中提取的DNA甲基化水平的年龄估计方法。选择ELOVL2上游区域的CpG岛作为目标位点，该区域在血液样本中是一种经过验证的生物标志物。CpG甲基化水平与年龄高度相关（r = 0.843，n = 29）。DNA甲基化水平随年龄的增加不受性别差异影响。此外，基于CpG岛甲基化状态的简单回归模型表现出中等准确性，实际年龄与预测年龄之间的平均绝对偏差为8.94岁。结果表明，实时MSP可以成为法医学场景中对身份不明尸体进行年龄预测的一种新工具。
