Largest-Ever Genetic Study Points to Nervous System Roots of Fibromyalgia

The largest-ever genetic study of fibromyalgia has identified new genetic risk factors for the condition and provided the strongest evidence yet that it is primarily a nervous system disorder rather than an autoimmune disease, with results published in Nature Medicine and highlighted by Fred Hutch Cancer Center this week.

2.5 Million People, 26 Risk Loci

Researchers analyzed genetic data from more than 2.5 million adults — 2,563,755 individuals, including 54,629 diagnosed with fibromyalgia — drawn from 11 health research cohorts across the US, UK, Finland, Estonia, Denmark and Iceland, involving 53 researchers from seven countries. The study was jointly led by Dr. Michael Wainberg of the Lunenfeld-Tanenbaum Research Institute and the University of Toronto, Dr. Nasa Sinnott-Armstrong of Fred Hutch Cancer Center and the University of Washington, and Dr. Hanna Ollila of the University of Helsinki and Massachusetts General Hospital. It identified 26 genetic risk loci, many implicating genes involved in brain and nerve function, including GPR52, DCC, DRD2/NCAM1, MDGA2 and CELF4.

Neural Enrichment and a Huntington Surprise

Heritability analyses showed enrichment in neural tissues and cell types, with the strongest signals in brain regions including the cortex, caudate, frontal cortex, putamen and anterior cingulate cortex — consistent with the central sensitisation model of heightened pain and sensory processing. The study found only modest genetic correlations with autoimmune disorders and no major histocompatibility complex signal, arguing against an autoimmune basis. The strongest single association was a coding variant in the HTT gene — the gene mutated in Huntington's disease — conferring roughly 9 percent increased odds of fibromyalgia, while another variant pointed at GPR52, a receptor that regulates HTT levels and is already being investigated as a drug target for Huntington's disease.

What Comes Next

The findings do not yet provide a genetic test for diagnosis or an immediate new treatment, but they offer biological starting points. The researchers have founded the Chronic Pain Genomics Consortium to investigate other chronic pain syndromes, starting with pelvic pain, in the hope that targeting shared nervous-system mechanisms could benefit a whole cluster of chronic pain conditions.