Researchers have spent decades trying to pin down the cause (or causes) of chronic fatigue syndrome (CFS or ME/CFS), but so far the research has created more controversy than clarity. Researchers have found insufficient or conflicting evidence on prospective causes including infection, immune dysfunction, endocrine-metabolic dysfunction, neurally mediated hypotension and depression. Data on sleep disruption is limited.
Meanwhile, studies on a genetic component are showing promise. For the details on genetic research, read this excerpt from UpToDate, an electronic reference that's widely used and trusted by doctors.
Genetic Research & Chronic Fatigue Syndrome: Details from UpToDate
"Data generated from 227 patients with CFS who underwent detailed clinical evaluations, measurements of sleep physiology, cognitive function, autonomic nervous system function, and blood analyses of the sequence and expression of 20,000 genes have linked CFS to certain genes involved in immune and stress responses. The following findings were noted in CFS patients compared with controls:
- Different levels of expression of genes with roles in the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system; functionally these led to differences in how the body responds to hormones and other chemical messengers that are released in response to challenges and stressors such as trauma, injury, and other adverse events.
- DNA sequence changes in three genes associated with brain function, stress reactions, and emotional responses.
"The findings suggest that difficulty managing stress may be linked to the development of CFS. They also suggest that there is not a single cause of CFS, but that there may be a number of stress-related triggers in those with a genetic predisposition. These studies are the strongest evidence for a biologic basis for CFS and may help to more effectively diagnose and develop effective treatments for this disease."
Remember that "stress" isn't always psychological -- it can be physiological as well. Essentially what researchers are saying is that people with genetic abnormalities in their stress-response systems may be especially prone to CFS. When those people encounter certain stressors, it triggers the illness. Such stressors could include:
- Viral or bacterial infection
- Exposure to toxins
- Chronic psychological stress
Some prominent CFS researchers are exploring genetic abnormalities in the search for better treatments and a greater understanding of the condition.
Want to learn more? See UpToDate’s topic, "Patient Information: Chronic Fatigue Syndrome" for additional in-depth, current and unbiased medical information on chronic fatigue syndrome, including expert physician recommendations.
Source: "Clinical features and diagnosis of chronic fatigue syndrome" UpToDate. Accessed: January 2009.
