The genetic architecture of fibromyalgia across 2.5 million individuals

A large-scale study of 2.5 million individuals has established a firm biological basis for fibromyalgia. Researchers conducted a multi-ancestry genome-wide association study to identify the genetic underpinnings of this condition. They found 26 independent risk loci that contribute to the syndrome, moving the field past long-standing debates about its origin.

The findings confirm that fibromyalgia is primarily a central nervous system disorder. The genetic heritability of the condition is concentrated in brain tissues and neuronal cell types. Specifically, the researchers identified enrichment in hippocampal dentate gyrus neurons and enteric neurons. These findings support the central sensitization model, where the brain becomes overly sensitive to sensory input. This biological connection helps explain common cognitive symptoms like brain fog.

A notable finding is the association with the Huntingtin gene. While this gene is linked to Huntington’s disease, the specific variant found in this study is common and distinct from the rare repeat expansions that cause the neurological disorder. This variant increases the odds of fibromyalgia by about 9 percent. Additional associations were found with genes involved in synaptic organization, neurodevelopment, and inflammatory pathways, including targets currently investigated for chronic pain.

The study also addressed the frequent overlap of fibromyalgia with other conditions. The researchers observed significant genetic correlations with irritable bowel syndrome, post-traumatic stress disorder, depression, and localized pain conditions. This shared genetic architecture suggests a transdiagnostic central nervous system vulnerability that predisposes individuals to these comorbidities.

While fibromyalgia is much more common in women, the study found no significant sex differences in the genetic architecture of the condition. This indicates that the prevalence gap is likely driven by nongenetic biological factors, environmental exposures, or diagnostic patterns. These results provide new, concrete molecular starting points for future therapeutic development. The researchers identified potential targets for drug repurposing and gene therapy, marking a significant step forward in understanding the biology of chronic pain.