Integration of DNA methylation & health scores identifies subtypes in myalgic encephalomyelitis/chronic fatigue syndrome.
de Vega, Wilfred C, Erdman, Lauren, Vernon, Suzanne D et al. · Epigenomics · 2018 · DOI
Quick Summary
Researchers studied 70 women with ME/CFS and found that their DNA showed different chemical patterns in immune cells. These chemical differences matched up with specific symptoms and health problems that patients reported. The study identified four distinct subtypes of ME/CFS, each with its own pattern of DNA changes and symptom profile, suggesting that ME/CFS may not be one uniform condition but rather several related conditions with different underlying biology.
Why It Matters
This study provides objective evidence that ME/CFS is not a single disease but comprises distinct biological subtypes with different immune and metabolic signatures. Identifying these subtypes could help explain why patients respond differently to treatments and move the field toward precision medicine approaches tailored to individual subtype profiles.
Observed Findings
Four distinct ME/CFS subtypes were identified based on DNA methylation and symptom integration.
Methylation changes occurred in 1,939 CpG sites, with particular enrichment in immune response genes.
Physical functioning and postexertional malaise symptoms differed significantly between subtypes.
Three RAND-36 health categories and five DePaul Symptom Questionnaire measures varied by subtype.
Methylation patterns in immune cells correlated with specific symptom profiles.
Inferred Conclusions
ME/CFS comprises at least four biologically distinct subtypes with different immune methylation signatures and symptom patterns.
Immune gene methylation differences may underlie the heterogeneous symptom presentation observed in ME/CFS patients.
Metabolic and immune dysregulation varies by subtype and may explain differential treatment responses between patients.
Remaining Questions
Are these four subtypes stable over time, or do patients' subtype classification change with disease progression or treatment?
Do these methylation-defined subtypes predict treatment response or prognosis?
What This Study Does Not Prove
This study does not prove that DNA methylation changes cause ME/CFS symptoms—it only shows they are associated. The cross-sectional design cannot establish whether methylation differences precede disease onset or result from it. The findings are limited to women and require validation in larger, diverse populations and longitudinal studies.