Landmark GWAS of 2.5 Million Individuals Reveals 26 Genetic Risk Loci for Fibromyalgia, Implicating Nervous System Origins
核心洞察
A multi-ancestry genome-wide association study across 11 cohorts identified 26 independent genome-wide significant risk loci for fibromyalgia (搜索), establishing a clear biological basis for the condition.
The top association was found in the Huntingtin (HTT (搜索)) gene, with a coding variant (rs149109767-A) conferring approximately 9% increased odds of fibromyalgia (搜索), revealing an unexpected link to Huntington's disease (搜索) biology.
Heritability enrichment analyses showed exclusive enrichment in neural tissues and cell types, with the strongest signal in dentate gyrus neurons, confirming fibromyalgia (搜索) as a nervous system disorder.
A massive international collaboration has produced the largest genome-wide association study (GWAS) of fibromyalgia (搜索) to date, analyzing genetic data from over 2.5 million individuals across 11 cohorts and identifying 26 independent genome-wide significant risk loci for the chronic pain condition. The findings, published in Nature Medicine, provide the most comprehensive genetic evidence to date that fibromyalgia has a clear biological basis rooted in the nervous system.
The primary meta-analysis encompassed 54,629 fibromyalgia (搜索) cases and 2,509,126 controls, with cases defined by ICD-10 code M79.7 in inpatient and/or primary care records. Prevalence varied sixfold across cohorts, from 1.2% in the Estonian Biobank to 7.5% in the Michigan Genomics Initiative, with a median prevalence of 2.5%.
A Surprising Link to Huntington's Disease (搜索)
The most significant association in the primary analysis was with rs149109767-A (OR = 1.09, P = 2.2 × 10⁻¹²), an inframe glutamic acid deletion in the Huntingtin (HTT (搜索)) gene. HTT is the causal gene for Huntington's disease (搜索) (HD), a severe, progressive and fatal neurodegenerative disorder. The fibromyalgia (搜索)-associated variant is located in exon 58 of the 67-exon HTT gene, far from the exon 1 repeat-expansion region that causes HD, but is part of the HD-associated 'A1' haplotype found in Europeans.
"This work changes how we think about fibromyalgia (搜索) at a fundamental level," said Dr. Michael Wainberg, an investigator at the Lunenfeld-Tanenbaum Research Institute and the University of Toronto and co-senior author on the paper. "For decades, patients have been dismissed or told their pain is simply psychological. Our findings confirm the condition has a clear biological basis."
The researchers investigated whether the fibromyalgia (搜索) variant is associated with HD using a six-European-cohort HD GWAS meta-analysis. The top HD association (rs71180116, OR = 44.3, P = 2.62 × 10⁻³⁰) was not in strong LD with the lead fibromyalgia variant (r² = 0.0055) and showed no association with fibromyalgia (OR = 1.027, P = 0.41). While the fibromyalgia variant did associate with HD risk (OR = 2.118, P = 0.00354), this association disappeared after conditioning on the HD-causing repeat expansion.
A second association with a possible HD link was identified: rs6657341-A (OR = 0.961, P = 7.1 × 10⁻⁹), an intronic variant in RABGAP1L, located approximately 150 kilobases upstream of GPR52 (搜索). GPR52 is a brain-specific orphan G-protein-coupled receptor being investigated as a drug target for HD, as it regulates HTT (搜索) levels.
Pain Processing and Brain-Related Mechanisms
Several associations implicated pain processing pathways. One involved rs11664242 near CELF4, which encodes an RNA-binding protein that reduces pain and sensory sensitivity by negatively regulating nociceptor excitability. CELF4 gene therapy is an investigational therapeutic strategy for chronic pain.
Another notable brain association was with rs2734833, an intronic variant in DRD2 (搜索), which encodes the dopamine D2 receptor—the primary target of most antipsychotic drugs. The second-most significant association was with rs9862795 near CAMKV, which encodes a pseudokinase critical for dendritic spine maintenance, synaptic transmission, and synaptic plasticity.
Additional associations implicated genes linked to neurodevelopment and intellectual disability, including DCC (axon guidance), BCL11A (haploinsufficiency causes intellectual disability and autism), BPTF (neurodevelopmental disorder with intellectual disability), and PPP2R2B (CAG repeat expansion causes spinocerebellar ataxia 12).
Heritability Exclusively Enriched in Neural Tissues
Using LD score regression applied to specifically expressed genes (LDSC-SEG), the researchers quantified fibromyalgia (搜索) heritability enrichment across 53 GTEx tissues and 119 cell types from the mouse PanSci single-cell atlas. The results were striking: all five GTEx tissues with Bonferroni-significant enrichment were brain regions—cortex, caudate, frontal cortex, putamen, and anterior cingulate cortex—and 12 of 13 enriched cell types were neuronal.
The strongest cell-type association was with neurons from the dentate gyrus (P = 1.3 × 10⁻⁶), a hippocampal region critical for contextualizing sensory experience, including pain. Significant enrichments were also found in enteric neurons (P = 7.9 × 10⁻⁶) and diverse interneurons, cortical projection neurons, and striatal neurons. Even when grouping cell types by lineage, the only significant lineage was neural (P = 2.3 × 10⁻⁴).
Pervasive Genetic Correlations with Comorbid Disorders
Genetic correlation analyses between the European-only fibromyalgia (搜索) meta-analysis and 855 diseases in FinnGen yielded 337 Bonferroni-significant correlations. The strongest genetic overlap was with pain and musculoskeletal disorders, including cervicobrachial syndrome (rg = 0.87, P = 9.2 × 10⁻⁶⁵), myalgia (rg = 0.82, P = 9.4 × 10⁻⁴⁵), and hypermobility syndrome (rg = 0.79, P = 8.4 × 10⁻¹³).
Fibromyalgia (搜索) also showed substantial genetic correlations with mental and behavioral disorders, with post-traumatic stress disorder (rg = 0.78, P = 6.6 × 10⁻¹⁶) rivaling those of pain conditions. Strong correlations were evident for depression (rg = 0.63, P = 4.1 × 10⁻¹¹⁸), irritable bowel syndrome (rg = 0.70, P = 2.1 × 10⁻³⁵), and functional dyspepsia (rg = 0.67, P = 9.1 × 10⁻²⁴).
"We know that chronic pain syndromes cluster together in individuals and families and are genetically similar," said Professor Frances Williams, co-senior author and Professor of Genomic Epidemiology at King's College London. "Targeting the shared mechanisms underlying them could potentially benefit a whole cluster of disorders."
Notably, genetic correlations with autoimmune disorders were comparatively modest. The highest correlations in this category were with psoriatic arthropathies (rg = 0.41) and Sjögren's syndrome (rg = 0.39). Fibromyalgia (搜索) was more genetically correlated with seronegative rheumatoid arthritis (rg = 0.41) than seropositive RA (rg = 0.24), and with T2-low asthma (rg = 0.44) than T2-high asthma (rg = 0.27), further distinguishing fibromyalgia's genetic architecture from well-characterized inflammatory and autoimmune disease.
Sex-Stratified Analyses and Genetic Risk Prediction
Consistent with known sex differences in fibromyalgia (搜索) prevalence, 87.7% of cases (47,895) were female. While the lower number of male cases yielded less statistical power—2 loci in males versus 21 in females—the inter-sex genetic correlation in European-ancestry individuals was 1.03 (P = 2.9 × 10⁻¹⁶), statistically indistinguishable from perfect correlation. Thus, fibromyalgia's genetic architecture is largely consistent between sexes.
Polygenic risk scores (PRS) constructed from the leave-UK Biobank-out meta-analyses showed modest predictive ability, commensurate with fibromyalgia (搜索)'s observed-scale heritability of 10.4% (95% CI 9.8% to 11.0%). Performance was highest among European-ancestry participants (AUC = 0.59), with attenuated accuracy in South Asian (AUC = 0.55) and African (AUC = 0.55) populations.
Despite modest AUCs, the PRS effectively stratified individuals by risk. Compared with the middle quintile, European-ancestry participants in the highest PRS quintile had a fibromyalgia (搜索) odds ratio of 1.5 (95% CI 1.4 to 1.7), while those in the lowest quintile had an odds ratio of 0.63 (95% CI 0.57 to 0.68). Prevalence increased from approximately 1.0% in the lowest quintile to 2.4% in the highest.
Pleiotropy and Clinical Implications
Phenome-wide association analyses revealed that the 26 lead variants are highly pleiotropic. The most frequent GWAS Catalog associations were with educational attainment (10 variants), body mass index (8), type 2 diabetes (7), pain intensity (6), and insomnia (6). In drug prescription analyses from FinnGen, the most frequent associations were with analgesics (14 variants) and anti-inflammatory/anti-rheumatic drugs (12 variants).
"Understanding how genes, environmental exposures, and life events jointly contribute to the risk of fibromyalgia (搜索) syndrome is critical," said Dr. Nasa Sinnott-Armstrong, Assistant Professor at Fred Hutch Cancer Center and co-senior author. "Further research into triggers of fibromyalgia and corresponding changes in neural tissues will help understand what drives fibromyalgia and how to treat it."
Professor Williams added: "This study provides important new insights into why some people develop fibromyalgia (搜索) syndrome and identifies biological pathways that could lead to new treatment approaches. One of these pathways is already the focus of drug trials for Huntington's disease (搜索), raising the possibility that existing pharmaceutical research could eventually benefit people with fibromyalgia."
The study's researchers have founded the Chronic Pain Genomics Consortium to investigate other chronic pain syndromes, starting with pelvic pain, viewing fibromyalgia (搜索) as only the beginning of a broader exploration of the landscape of chronic pain conditions.