Landmark-Høyvik, Hege, Reinertsen, Kristin V, Loge, Jon H et al. · PM & R : the journal of injury, function, and rehabilitation · 2010 · DOI
This study reviewed scientific literature to understand whether genetics (inherited traits) and epigenetics (chemical changes that affect how genes work) influence fatigue in people with ME/CFS and other conditions. The researchers found that while some biological systems appear to malfunction in people with persistent fatigue, no clear genetic or epigenetic markers have been reliably identified yet. The authors argue that future research needs to be larger, better-designed, and consider how genes, environment, and body systems work together.
This review identifies critical gaps in our understanding of why some people develop ME/CFS, pointing out that decades of research has not yet confirmed reproducible genetic or epigenetic markers. The findings underscore the need for better-designed, larger-scale studies that could eventually enable earlier diagnosis or personalized treatment approaches for patients. For patients, this explains why simple genetic tests do not yet exist for ME/CFS and highlights the complexity of the disease.
This review does not prove that genetic or epigenetic factors do not influence fatigue in ME/CFS—only that reliable markers have not yet been identified. The absence of confirmed findings reflects study design limitations rather than proof that genetics plays no role. The review does not establish which specific environmental, immune, or neurological factors are primary drivers of ME/CFS.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
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