Age-related DNA methylation analysis for forensic age estimation using post-mortem blood samples from Japanese...

Area of Science:

• Forensic Science
• Epigenetics
• Genetics

Background:

• Age estimation is a key aspect of forensic phenotyping.
• DNA methylation patterns offer a reliable method for age prediction.
• Previous studies identified candidate genes for age-related methylation.

Purpose of the Study:

• To develop a feasible age estimation model for Japanese individuals using DNA methylation.
• To identify specific CpG sites and genes strongly correlated with chronological age.
• To compare the performance of linear and quantile regression models for age prediction.

Main Methods:

• Selected 53 CpG sites across 11 candidate genes from prior research.
• Measured DNA methylation levels using massive parallel sequencing on 60 forensic blood samples.
• Employed multiple linear and quantile regression analyses to build age estimation models.

Main Results:

• Identified four CpG sites (ASPA, ELOVL2, ITGA4B, PDE4C) highly correlated with age in Japanese DNA samples (|R| > 0.75).
• Validated models on an independent dataset (n=30), achieving accurate predictions (MAD: linear=6.493 years; quantile=6.243 years).
• The quantile model demonstrated age-dependent prediction intervals, mirroring human aging.

Conclusions:

• Both linear and quantile regression models provide accurate age predictions for Japanese individuals.
• The quantile regression model is recommended due to its ability to provide dynamic, age-reflective prediction intervals.
• This epigenetic approach offers a valuable tool for forensic age estimation.