A significant study has identified a potential genetic link between fibromyalgia, a condition characterized by widespread pain, fatigue, and severe brain fog, and Huntington's disease, a devastating inherited neurological disorder. The findings, published in Nature Medicine, challenge previous assumptions about fibromyalgia's origins and suggest a clearer biological basis for the chronic illness.
The research analyzed genetic data from over 2.5 million adults, including approximately 55,000 individuals with fibromyalgia. This comprehensive analysis revealed 26 genetic variations associated with fibromyalgia, many of which are involved in brain and nervous system function. Notably, the study found a strong signal within the huntingtin (HTT) gene, the same gene responsible for causing Huntington's disease.
Huntington's disease is an incurable inherited disorder that progressively destroys nerve cells in the brain, impacting a person's ability to move, think, and control behavior. In the UK, around 7,000 people live with this condition.
Fibromyalgia, on the other hand, is estimated to affect between 1.8 million and 2.9 million adults in the UK, though actual numbers may be higher due to diagnostic challenges. While often affecting middle-aged women, it can be diagnosed in individuals over 25. Common symptoms include widespread pain, extreme sensitivity to pain and light, stiffness, and the commonly reported "fibro fog," which impairs concentration, memory, and speech.
Scientists previously discovered the HTT gene's role in Huntington's disease about 30 years ago. The current study's authors, including Michael Wainberg of the Lunenfeld-Tanenbaum Research Institute and University of Toronto, state that their findings fundamentally alter the understanding of fibromyalgia. "For decades, patients have been dismissed or told their pain is simply psychological. Our findings confirm the condition has a clear biological basis," Wainberg said.
The research also suggests that fibromyalgia might be a disorder of the nervous system rather than an autoimmune disease, a view that contrasts with some earlier findings. A 2021 study by King's College London had proposed that fibromyalgia symptoms were linked to immune system overactivity. However, the new study indicates that fibromyalgia could be a disorder affecting neural tissues.
Furthermore, the study found strong associations between fibromyalgia and other conditions such as back pain, irritable bowel syndrome, and post-traumatic stress disorder. Researchers hypothesize that shared problems within the nervous system might explain the co-occurrence of these conditions.
While genetic factors play a role, the researchers emphasize that genes alone are unlikely to cause fibromyalgia. They propose that environmental triggers, such as experiencing a painful condition like arthritis, may be necessary for the illness to develop. "Understanding how genes, environmental exposures, and life events jointly contribute to risk of fibromyalgia syndrome is critical," stated Nasa Sinnott-Armstrong from Fred Hutch Cancer Center and the University of Washington. "Further research into triggers of fibromyalgia and corresponding changes to neural tissues will help understand what drives fibromyalgia and how to treat it."
Interestingly, the study found no genetic differences between men and women, despite fibromyalgia being diagnosed approximately three times more often in women.