DNA methylation-based forensic framework for age prediction and body fluid identification using nanopore sequencing.

Area of Science:

• Forensic Science
• Genetics
• Epigenetics

Background:

• Forensic DNA phenotyping uses genetic and epigenetic markers to identify individuals when conventional methods fail.
• DNA methylation is crucial for estimating biological age and identifying body fluids, aiding crime scene investigations.
• Nanopore sequencing offers direct, real-time methylation detection, bypassing time-consuming traditional methods.

Purpose of the Study:

• To evaluate Nanopore's PromethION 2 platform for single-assay forensic epigenetic analysis.
• To assess its capability for biological age estimation and body fluid identification using low DNA quantities (<100 ng).

Main Methods:

• Utilized Nanopore PromethION 2 for direct DNA methylation analysis.
• Focused on forensic epigenetic markers for age prediction (epigenetic clocks) and body fluid identification.
• Investigated performance with low DNA input and varying read depth.

Main Results:

• Low read depth impacted methylation status accuracy, challenging precise age and body fluid identification.
• Age prediction models initially overestimated age, but a linear correction model significantly improved accuracy.
• Blood and saliva identification demonstrated high accuracy (4/4 samples) across different read depths.

Conclusions:

• Nanopore sequencing, particularly with adaptive sampling, holds potential for forensic age prediction and body fluid identification.
• Future research should validate analysis thresholds, enhance low-quantity DNA performance, expand body fluid identification, and address mixture analysis.