Somatic mutation as an explanation for epigenetic aging.

Area of Science:

• Genomics
• Epigenetics
• Aging Research

Background:

• Epigenetic clocks, based on DNA methylation, predict biological age.
• Cytosine methylation can lead to C-to-T mutations, suggesting a link between methylation changes and somatic mutation accumulation.

Purpose of the Study:

• To investigate the hypothesis that age-related DNA methylation changes reflect somatic mutation accrual.
• To determine if mutation accumulation can yield aging estimates analogous to epigenetic clocks.
• To explore the relationship between mutation hotspots and age-predictive methylation patterns.

Main Methods:

• Analysis of multimodal data from 9,331 human individuals.
• Examining the coincidence of CpG mutations with methylation changes.
• Developing mutation-based age prediction models.
• Comparing mutation-based age predictions with established epigenetic clocks.

Main Results:

• CpG mutations were found to coincide with methylation changes, impacting methylation patterns up to ±10 kilobases from the mutation site.
• Mutation-based age predictions showed agreement with epigenetic clock estimates.
• Individuals aging faster or slower than expected could be identified using mutation data.
• Genomic loci with age-accumulating mutations exhibited methylation patterns highly predictive of age.

Conclusions:

• A close coupling exists between the accumulation of sporadic somatic mutations and widespread age-related methylation changes.
• Somatic mutations provide a novel basis for aging estimation, complementing epigenetic clocks.
• Understanding this link offers insights into the molecular mechanisms of aging.