Arthritis Res Ther. 2007 Oct 26;9(5):R110 [Epub ahead of print]
Catechol-O-Methyl Transferase (COMT) gene haplotypes in Mexican and Spaniard patients with fibromyalgia.
Vargas-Alarcon G, Fragoso JM, Cruz-Robles D, Vargas A, Vargas A, Lao-Villadoniga JI, Garcia-Fructuoso F, Ramos-Kuri M, Hernandez F, Springall R, Bojalil R, Vallejo M, Martinez-Lavin M.
ABSTRACT: Autonomic dysfunction is frequent in patients with fibromyalgia. Heart rate variability analyses have demonstrated signs of ongoing sympathetic hyperactivity. Catecholamines are sympathetic neurotransmitters. Cathecol-O-methyl transferase (COMT), an enzyme, is the major catecholamine-clearing pathway. There are several single-nucleotide polymorphisms (SNPs) in the COMT gene associated with the different catecholamine-clearing abilities of the COMT enzyme. These SNPs are in linkage disequilibrium and segregate as "haplotypes". Healthy females with a particular COMT gene haplotype (ACCG) producing a defective enzyme are more sensitive to painful stimuli. The objective of our study was to define whether or not women with FM from two different countries (Mexico and Spain), have the COMT gene haplotypes that have been previously associated with greater sensitivity to pain. All the individuals in the study were female. Fifty-seven Mexican patients and 78 Spaniard patients were compared with their respective healthy control groups. All participants filled out the Fibromyalgia Impact Questionnaire (FIQ). Six COMT SNPs (rs2097903, rs6269, rs4633, rs4818, rs4680, and rs165599) were genotyped from peripheral blood DNA. In Spaniard patients there was a significant association between three SNPs (rs6269, rs4818, and rs4680) and the presence of FM when compared to healthy controls. Moreover, in Spaniard patients with the "high pain sensitivity" haplotype (ACCG) the disease, as assessed by the FIQ, was more severe. By contrast, Mexican patients displayed only a weak association between rs6269 and rs165599, and some FIQ subscales. In our group of Spaniard patients, there was a strong association between FM and the COMT haplotype previously associated with high pain sensitivity. This association was not observed in Mexican patients. Studies with larger sample size are needed in order to verify or amend these preliminary results.
PMID: 17961261 [PubMed - as supplied by publisher]