Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Forensic Genetics Research Unit, Ratchadapiseksompotch Fund, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Forensic Serology and DNA, King Chulalongkorn Memorial Hospital and Thai Red Cross Society, Bangkok, Thailand; Forensic Genetics Research Unit, Ratchadapiseksompotch Fund, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
Forensic Sci Int. 2021 Jan;318:110631. doi: 10.1016/j.forsciint.2020.110631. Epub 2020 Nov 28.
Chronological age estimation is an important piece of human identification used in forensic practice. Epigenetic modifications, especially DNA methylation, have been proposed to predict age. The methylation of the ELOVL2 gene is one of the age-related markers that could be tested in fresh or postmortem blood sample. We study the use of DNA methylation markers on the ELOVL2 gene and develop a prediction model to estimate the age from a postmortem blood sample using pyrosequencing. From 100 anonymous blood samples, a correlation study of DNA methylation and age was investigated. The regression analysis revealed 2 CpG sites for model prediction with an adjusted R value of 0.7 (p < 0.01). The model explained 74% of the variation in postmortem blood samples (n = 36) with a prediction error (RMSE) of 10.2 years and a mean absolute deviation (MAD) of 7.1 years, whereas the model (excluding a younger age group) had improved with a RMSE of 5.6 years and a MAD of 4.2 years. The performance parameters were analyzed in several simulated models and indicated that these markers are advantageous for age estimation in forensic scenarios. Finally, a robustness and reproducibility of the pyrosequencing technique would enable this approach to be the part of an age prediction in forensic investigation.
年龄推断是法医学实践中用于身份识别的重要方法。表观遗传修饰，特别是 DNA 甲基化，已被提议用于预测年龄。ELOVL2 基因的甲基化是可在新鲜或死后血液样本中检测的与年龄相关的标志物之一。我们研究了 ELOVL2 基因上的 DNA 甲基化标记物的用途，并使用焦磷酸测序法开发了一种从死后血液样本估算年龄的预测模型。对 100 份匿名血液样本进行了 DNA 甲基化与年龄的相关性研究。回归分析显示，有 2 个 CpG 位点可用于模型预测，调整后的 R 值为 0.7（p < 0.01）。该模型解释了 74%的死后血液样本（n=36）中的变异，预测误差（RMSE）为 10.2 年，平均绝对偏差（MAD）为 7.1 年，而不包括年龄较小的年龄组的模型，其 RMSE 为 5.6 年，MAD 为 4.2 年。对几个模拟模型的性能参数进行了分析，表明这些标志物对于法医场景中的年龄估计具有优势。最后，焦磷酸测序技术的稳健性和可重复性将使该方法成为法医调查中年龄预测的一部分。
