MtDNA population variation in Myalgic encephalomyelitis/Chronic fatigue syndrome in two populations: a study of mildly deleterious variants. — CFSMEATLAS
MtDNA population variation in Myalgic encephalomyelitis/Chronic fatigue syndrome in two populations: a study of mildly deleterious variants.
Venter, Marianne, Tomas, Cara, Pienaar, Ilse S et al. · Scientific reports · 2019 · DOI
Quick Summary
This study looked at mitochondrial DNA (the genetic material in the energy-producing parts of our cells) in people with ME/CFS to see if differences in this DNA might help explain the condition. Researchers compared DNA samples from ME/CFS patients in the UK and South Africa to look for variations. Interestingly, they found that ME/CFS patients were less likely to have certain common genetic variations that most people carry, but they did not find any confirmed disease-causing mutations.
Why It Matters
Mitochondrial dysfunction is increasingly suspected as a contributor to ME/CFS given the severe fatigue characteristic of mitochondrial diseases. This study provides evidence that mitochondrial DNA variation patterns differ in ME/CFS patients, offering a new avenue for understanding the biological basis of the condition and potentially identifying patients who might benefit from mitochondria-targeting interventions.
Observed Findings
ME/CFS patients in both UK and South African cohorts showed an excess of individuals lacking mildly deleterious mtDNA population variants compared to background populations.
No confirmed pathogenic mtDNA mutations were identified in either cohort.
The pattern of mtDNA variation was consistent across two geographically distinct populations, suggesting a robust association.
Severity of ME/CFS (moderate vs. severe in UK cohort) was examined alongside these mtDNA patterns.
Inferred Conclusions
Mitochondrial DNA variation patterns may play a role in ME/CFS pathophysiology.
The reduced frequency of mildly deleterious variants in ME/CFS patients suggests a distinct population genetic signature associated with the condition.
Mitochondrial function and bioenergetics warrant further investigation as potential mechanisms in ME/CFS.
Remaining Questions
What is the biological mechanism explaining why reduced mildly deleterious mtDNA variants associate with ME/CFS?
Do these mtDNA variation patterns correlate with measures of mitochondrial function or cellular energy metabolism in ME/CFS patients?
Can these findings be replicated in larger, more diverse populations, and do they predict disease severity or treatment response?
What This Study Does Not Prove
This study does not prove that mitochondrial DNA variations cause ME/CFS, nor does it identify specific genetic mutations responsible for the condition. The association between reduced mildly deleterious variants and ME/CFS does not establish causation, and the biological mechanism explaining this population-level difference remains unclear. The findings require replication in larger populations and functional studies to determine clinical significance.
Tags
Symptom:Fatigue
Biomarker:Gene Expression
Phenotype:Severe
Method Flag:Weak Case DefinitionSmall SampleExploratory OnlyMixed CohortSevere ME Included