School of Criminal Justice and Criminalistics, California State University, 1800 Paseo Rancho Castilla, Los Angeles, CA, 90032, USA.
California Forensic Science Institute, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA, 90032, USA.
Int J Legal Med. 2021 Nov;135(6):2163-2173. doi: 10.1007/s00414-021-02650-8. Epub 2021 Jul 10.
Chronological age estimation may offer valuable investigative leads in human identification cases. Bisulfite pyrosequencing analysis of single CpG sites on five genes (KLF14, ELOVL2, C1orf132, TRIM59, and FHL2) was performed on 264 postmortem blood samples from individuals aged 3 months to 93 years. The goals were to develop age prediction models based on the correlation between the methylation profile and chronological age and to assess the accuracy of the prediction. Linear regression between methylation levels and age at each CpG site revealed that the five markers show a statistically significant correlation with age. The methylation data from a training set of 160 postmortem blood samples were used to develop an age prediction model with a correlation coefficient of 0.65, explaining 73.1% of age variation, with a mean absolute deviation from the chronological age of 7.60 years. The accuracy of the model was evaluated with a test set of 72 samples producing a mean absolute deviation of 7.42 years. The training and test sets were also categorized by specific age groups to assess accuracy and deviation from chronological age. The data for both sets revealed a lower prediction potential as an individual increases in age, particularly for the age categories above 50 years.
年龄推断在法医学个人识别中具有重要价值。本研究应用焦磷酸测序技术，对五个基因（KLF14、ELOVL2、C1orf132、TRIM59 和 FHL2）上的 264 个 CpG 位点进行了甲基化分析，研究对象为年龄在 3 个月至 93 岁的个体。研究目的是建立基于甲基化特征与实际年龄的相关关系的年龄推断模型，并评估其预测精度。线性回归分析显示，在每个 CpG 位点，甲基化水平与年龄均存在显著相关性。通过 160 例尸检血液样本建立年龄预测模型，其相关系数为 0.65，可解释 73.1%的年龄变化，与实际年龄的平均绝对偏差为 7.60 岁。采用另外 72 例尸检血液样本的测试集评估模型的准确性，平均绝对偏差为 7.42 岁。本研究还按照特定年龄组对训练集和测试集进行了分类，以评估其对特定年龄组的准确性和与实际年龄的偏差。数据表明，该模型的预测能力随年龄的增加而降低，特别是在 50 岁以上的年龄组。
