Abstract
INTRODUCTION: The association between Fibromyalgia (FM) and the FMR1 gene premutation has been suggested, but remains inconclusively established. Previous studies often focus on whether women with FM have the FMR1 premutation, while a more appropriate approach would involve examining FM manifestation in women with the premutation. FM is a condition with multifactorial etiology, and while the rarity of the FMR1 premutation makes it unlikely that most FM cases are linked to this variation, an increased prevalence of FM among premutation carriers is still plausible. The authors present a pilot study with a more effective approach for sample definition that shows a trend toward confirming this association. OBJECTIVE: To investigate the association between FM and the FMR1 premutation, using a study design that focuses on FM occurrence in women with the premutation, rather than the presence of the premutation in women with FM. METHOD: FM occurrence was evaluated in 140 Brazilian women aged 30 to 59, including 70 premutation carriers and 70 controls. RESULTS: FM was diagnosed using the 2016 American College of Rheumatology (ACR) criteria. FM frequency was 25.71% among premutation carriers, compared to 12.86% in controls (p = 0.087). Relative risk (RR = 2) analysis showed a higher risk in the premutation group (95% Confidence Interval: 0.965‒4.143, p = 0.0621). CONCLUSIONS: This study employs a robust methodology with an improved sample definition and consistent diagnostic criteria. However, larger studies are needed to confirm the association and achieve statistical significance; the authors also provide a sample size calculation for future research.