Serotonin receptor (5-HT 2A) and catechol-O-methyltransferase (COMT) gene polymorphisms: triggers of fibromyalgia?
BACKGROUND
Fibromyalgia is a rheumatic syndrome characterized by diffuse and chronic pain associated with fatigue, sleep disorders, anxiety, depression, memory loss, and dizziness. Although the physiological mechanisms that control fibromyalgia have not been precisely established, neuroendocrine, genetic or molecular factors may be involved in fibromyalgia.


OBJECTIVE
The aim of the present study was to characterize serotonin receptor (5-HT2A) and catechol-O-methyltransferase (COMT) gene polymorphisms in Brazilian patients with fibromyalgia and to evaluate the participation of these polymorphisms in the etiology of the disease.


METHODS
Genomic DNA extracted from 102 blood samples (51 patients, 51 controls) was used for molecular characterization of the 5-HT2A and COMT gene polymorphisms by PCR-RFLP.


RESULTS
Analysis of the 5-HT2A polymorphism revealed a frequency of 25.49% C/C, 49.02% T/C and 25.49% T/T in patients, and of 17.65% C/C, 62.74% T/C and 19.61% T/T in the control group, with no differences between the two groups.Analysis of the COMT polymorphism in patients showed a frequency of 17.65% and 45.10% for genotypes H/H and L/H, respectively. In the control group the frequency was 29.42% for H/H and 60.78% for L/H, also with no differences between the two groups. However, there was a significant difference in the frequency of the L/L genotype between patients (37.25%) and controls (9.8%), which permitted differentiation between the two groups.


CONCLUSIONS
The L/L genotype was more frequent among fibromyalgia patients. Though considering a polygenic situation and environmental factors, the molecular study of the rs4680 SNP of the COMT gene may be helpful to the identification of susceptible individuals.
Unidade de Biotecnologia, Universidade de Ribeirão Preto, SP, Brasil.
Josie Budag
JB
Matsuda
Flávia Regina
FR
Barbosa
Lucas Junqueira Fernandes
LJ
Morel
Suzelei de Castro
Sde C
França
Sonia Marli
SM
Zingaretti
Lucienir Maria
LM
da Silva
Ana Maria Soares
AM
Pereira
Mozart
M
Marins
Ana Lúcia
AL
Fachin
D002394:Catechol O-Methyltransferase / Q000235:genetics*; D005260:Female; D005356:Fibromyalgia / Q000209:etiology / Q000235:genetics*; D006801:Humans; D008875:Middle Aged; D011110:Polymorphism, Genetic; D044402:Receptor, Serotonin, 5-HT2A / Q000235:genetics*; D011795:Surveys and Questionnaires
D044402:Receptor, Serotonin, 5-HT2A; D002394:Catechol O-Methyltransferase