A Significant Association Between rs2295190 Polymorphism of the ESR1 Gene and Fibromyalgia Syndrome.

Fibromyalgia syndrome (FMS) is a multifactorial disease characterized by chronic diffuse pain. Genetic factors are also involved in the etiology. However, there is not enough information on the genetic factors that play a role in the pathogenesis of FMS. The aim of this study is to investigate the relationship between estrogen receptor 1 gene (ESR1) 594G>A (rs2228480) and 325C>G (rs2295190) polymorphisms and fibromyalgia syndrome (FMS). A total of 294 women, 146 of who were FMS patients and 148 of whom were healthy controls, were enrolled in the study. The instruments used to collect data from patients included patient follow-up form, Visual Analogue Scale (VAS), and Fibromyalgia Impact Questionnaire (FIQ). Genotyping of ESR1 594G>A and 325C>G polymorphisms in the extracted DNA samples was performed using an RT-PCR device and TaqMan hydrolysis probes. It was found that, for rs2295190 polymorphism, patients with CG and GG genotypes versus CC genotypes showed a decreased risk for FMS (OR: 0.442; 95% CI: 0.234-0.833). But there were no significant differences were found in the genotype distribution of  rs2228480 polymorphism between the FMS patients and controls. The intragroup evaluation of FMS patients revealed no significant association between symptoms, pain score, FIQ score, and polymorphisms (p>0.05). We are of the opinion that there is a significant association between ESR1 rs2295190 polymorphism and FMS and that this polymorphism may be protective against FMS. However, there is a need for comprehensive studies on different populations to obtain clearer data as well as further studies to elucidate the possible mechanism of association.

Potassium Ion Channel Protein (KCNH) Levels in Patients with Fibromyalgia Syndrome.

Although there is not yet full clarity of the pathogenesis of fibromyalgia syndrome (FM), central sensitization is considered to be responsible. The purpose of this study was to measure the plasma levels of potassium ion channel proteins (human KCNH2, KCNH6 and KCNH7) in FM patients and healthy control subjects. The study sample includes 76 newly diagnosed FM patients and 79 healthy individuals. Venous blood samples were taken to measure the plasma levels of KCNH2, KCNH6 and KCNH7. Pain severity in FM patients was assessed using a visual analog scale (VAS). Bioinformatics analysis was performed using the STRING v 11 Protein interaction tool. Age, gender and body mass index were seen to be similar in both groups. In comparisons between FM and control groups, KCNH2 plasma levels was found to be significantly lower in the FM group. No significant correlation was found between plasma levels of KCNH2, KCNH6 and KCNH7 protein levels and VAS score of patients with FM. The KCNH2 protein had a high homology score with 9 proteins. The plasma levels of KCNH2 FM patients were found to be lower than those of the healthy control subjects, no difference was determined in respect of the plasma levels of KCNH6 and KCNH7. These results may be of use in guiding future studies on the pathogenesis of FM.

Serum Calcitonin Gene-Related Peptide and Receptor Protein Levels in Patients With Fibromyalgia Syndrome: A Cross-Sectional Study.

OBJECTIVES: This study aims to compare the serum calcitonin gene-related peptide (CGRP) and CGRP receptor protein levels between patients with fibromyalgia syndrome (FM) and healthy control subjects. PATIENTS AND METHODS: The study included 88 patients (7 males, 81 females; mean age 44.5±9.1 years; range, 20 to 72 years) newly-diagnosed with FM according to the 2010 American College of Rheumatology criteria and 88 healthy volunteers (6 males, 82 females; mean age 43.0±6.1 years; range, 20 to 57 years). Venous blood samples were collected from both groups for the measurement of the levels of serum CGRP and CGRP receptor proteins (receptor component protein [RCP], receptor activity modifying protein 1 [RAMP 1] and calcitonin receptor-like receptor [CLR]). RESULTS: A comparison of the serum CGRP, CLR and RCP levels of the FM and control groups revealed a statistically significant difference (p=0.001, p=0.005, p=0.001, respectively). The difference between the groups in respect of the serum RAMP 1 levels was not statistically significant (p=0.107). CONCLUSION: The serum CGRP, CLR and RCP levels were found to be higher in the FM patients, but no difference was determined between the FM patients and the healthy control group in respect of the RAMP 1 level. These results can be of guidance for further clinical studies of the etiopathogenesis and treatment of FM.