Influence of the interaction between environmental quality and T102C SNP in the HTR2A gene on fibromyalgia susceptibility.

Objectives: This study aimed to investigate the genetic influence of the T102C polymorphism of the 2A serotonin receptor gene (HTR2A) and its interaction with environmental aspects, such as exposure to noise, traffic, climate, and opportunities to acquire new information, physical protection, and security, among others, as possible risk factors for developing fibromyalgia syndrome (FMS).

Methods: Forty-one FMS patients and 49 controls were evaluated. Environmental factors were evaluated by application of the V domain of the WHOQOL-100 questionnaire. Patients were asked that their answers represented only the periods preceding the onset of symptoms. The T102C variant of the HTR2A gene was determined through PCR/RFLP.

Results: Among patients, the frequency of carriers of the 102C allele was higher than in controls (76.5% vs. 50%; P = 0.028). The scores of the V domain were lower in patients than in controls, indicating a worst perception of the environmental quality by patients (P < 0.001). The factor "lack of opportunities for acquiring new information and skills" increased the chance of developing FMS by almost 14-fold (P = 0.009). The factor "low quality of social care and health" together with the presence of the 102C allele also increased this chance by more than 90-fold (P = 0.005). However, carriers of the same allele who have high quality social care and health are not at a higher risk to develop FMS.

Conclusion: These data suggest that these factors may predispose to FMS, especially in carriers of the 102C allele. However, studies with larger samples are required to confirm this hypothesis.