结合骨骼和牙齿年龄的 DNA 甲基化标志物以提高儿童的年龄估计。
DNA methylation markers in combination with skeletal and dental ages to improve age estimation in children.
机构信息
XinHua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; MOE-Shanghai Key Laboratory of Children's Environmental Health, Shanghai, China; Department of Pediatric Dentistry, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; MOE-Shanghai Key Laboratory of Children's Environmental Health, Shanghai, China.
出版信息
Forensic Sci Int Genet. 2018 Mar;33:1-9. doi: 10.1016/j.fsigen.2017.11.005. Epub 2017 Nov 17.
Age estimation is critical in forensic science, in competitive sports and games and in other age-related fields, but the current methods are suboptimal. The combination of age-associated DNA methylation markers with skeletal age (SA) and dental age (DA) may improve the accuracy and precision of age estimation, but no study has examined this topic. In the current study, we measured SA (GP, TW3-RUS, and TW3-Carpal methods) and DA (Demirjian and Willems methods) by X-ray examination in 124 Chinese children (78 boys and 46 girls) aged 6-15 years. To identify age-associated CpG sites, we analyzed methylome-wide DNA methylation profiling by using the Illumina HumanMethylation450 BeadChip system in 48 randomly selected children. Five CpG sites were identified as associated with chronologic age (CA), with an absolute value of Pearson's correlation coefficient (r)>0.5 (p<0.01) and a false discovery rate<0.01. The validation of age-associated CpG sites was performed using droplet digital PCR techniques in all 124 children. After validation, four CpG sites for boys and five CpG sites for girls were further adopted to build the age estimation model with SA and DA using multivariate linear stepwise regressions. These CpG sites were located at 4 known genes: DDO, PRPH2, DHX8, and ITGA2B and at one unknown gene with the Illumina ID number of 22398226. The accuracy of age estimation methods was compared according to the mean absolute error (MAE) and root mean square error (RMSE). The best single measure for SA was the TW3-RUS method (MAE=0.69years, RMSE=0.95years) in boys, and the GP method (MAE=0.74years, RMSE=0.94years) in girls. For DA, the Willems method was the best single measure for both boys (MAE=0.63years, RMSE=0.78years) and girls (MAE=0.54years, RMSE=0.68years). The models that incorporated SA and DA with the methylation levels of age-associated CpG sites provided the highest accuracy of age estimation in both boys (MAE=0.47years, R=0.886) and girls (MAE=0.33years, R=0.941). Cross validation of the results confirmed the reliability and validity of the models. In conclusion, age-associated DNA methylation markers in combination with SA and DA greatly improve the accuracy of age estimation in Chinese children. This method may be applied in forensic science, in competitive sports and games and in other age-related fields.
年龄估算是法医学、竞技体育和其他与年龄相关领域的关键，但目前的方法并不理想。将与年龄相关的 DNA 甲基化标记与骨骼年龄（SA）和牙齿年龄（DA）相结合，可能会提高年龄估计的准确性和精密度，但尚无研究对此进行探讨。在本研究中，我们通过 X 射线检查测量了 124 名 6-15 岁中国儿童（78 名男孩和 46 名女孩）的 SA（GP、TW3-RUS 和 TW3-Carpal 方法）和 DA（Demirjian 和 Willems 方法）。为了鉴定与年龄相关的 CpG 位点，我们使用 Illumina HumanMethylation450 BeadChip 系统对 48 名随机选择的儿童进行了全基因组 DNA 甲基化谱分析。确定了 5 个与 CA 相关的 CpG 位点，其 Pearson 相关系数（r）绝对值>0.5（p<0.01）且错误发现率<0.01。使用微滴式数字 PCR 技术在所有 124 名儿童中对与年龄相关的 CpG 位点进行了验证。验证后，我们在男孩中进一步采用了 4 个 CpG 位点，在女孩中采用了 5 个 CpG 位点，结合 SA 和 DA，采用多元线性逐步回归法建立了年龄估计模型。这些 CpG 位点位于 4 个已知基因（DDO、PRPH2、DHX8 和 ITGA2B）和 1 个未知基因（Illumina ID 编号为 22398226）上。根据平均绝对误差（MAE）和均方根误差（RMSE）比较了年龄估计方法的准确性。对于 SA，男孩中 TW3-RUS 方法（MAE=0.69 岁，RMSE=0.95 岁）和女孩中 GP 方法（MAE=0.74 岁，RMSE=0.94 岁）的单项评估效果最好。对于 DA，Willems 方法是男孩（MAE=0.63 岁，RMSE=0.78 岁）和女孩（MAE=0.54 岁，RMSE=0.68 岁）的最佳单项评估方法。综合 SA 和 DA 以及与年龄相关的 CpG 位点的甲基化水平的模型，在男孩（MAE=0.47 岁，R=0.886）和女孩（MAE=0.33 岁，R=0.941）中均提供了最高的年龄估计准确性。结果的交叉验证证实了模型的可靠性和有效性。总之，与年龄相关的 DNA 甲基化标记与 SA 和 DA 相结合，极大地提高了中国儿童的年龄估计准确性。这种方法可能适用于法医学、竞技体育和其他与年龄相关的领域。
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