Dynamic Epigenetic Changes during a Relapse and Recovery Cycle in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.
Helliwell, Amber M, Stockwell, Peter A, Edgar, Christina D et al. · International journal of molecular sciences · 2022 · DOI
Quick Summary
This study looked at how a person's DNA changes during ME/CFS relapses by examining two patients' genetic material multiple times over several months as they experienced a relapse and recovery. The researchers found that during relapses, the patients' DNA showed much larger changes in a process called methylation (a chemical marking system that controls which genes are active) compared to healthy people. These changes affected genes involved in metabolism, immune function, and inflammation—processes that are important in ME/CFS.
Why It Matters
Understanding what happens at the molecular level during ME/CFS relapses could help identify early warning signs and develop strategies to prevent or reduce relapse severity. This study demonstrates that DNA methylation patterns may serve as biomarkers for disease activity, potentially enabling personalized monitoring and intervention in individual patients.
Observed Findings
Methylome variability was 10-20-fold higher in ME/CFS patients compared to healthy controls during the study period.
During relapse, methylation changes occurred in regulatory-active genomic regions of both patients' DNA.
Patient 1's relapse-associated methylation changes affected regulatory regions linked to 157 downstream genes.
Patient 2's relapse-associated methylation changes affected regulatory regions linked to 127 downstream genes.
The affected genes were associated with metabolic, immune, and inflammatory functions despite different methylation patterns between patients.
Inferred Conclusions
DNA methylation patterns change dynamically during ME/CFS relapses in ways that differ between individuals but converge on similar physiological dysfunctions.
DNA methylation signatures may represent a measurable marker of disease variability that could help track individual patient disease activity.
Epigenetic monitoring may have practical applications for developing strategies to reduce relapse frequency in ME/CFS patients.
Remaining Questions
What triggers the methylation changes that initiate a relapse in ME/CFS patients?
Can methylation signatures predict an upcoming relapse before clinical symptoms appear?
What This Study Does Not Prove
This study does not prove that methylation changes cause relapses—only that they occur together. The small sample size (two patients) limits generalizability, and the findings must be replicated in larger populations before clinical applications can be established. The study also does not explain what triggers these methylation changes in the first place.
Tags
Symptom:Fatigue
Biomarker:Gene Expression
Phenotype:Severe
Method Flag:Weak Case DefinitionNo ControlsSmall SampleExploratory Only