Association of Catechol-O-Methyl-Transferase and Estrogen Receptors polymorphism with Severity of Temporomandibular Disorder in Iranian Patients.

Background: There are many studies which strongly suggest that the pathophysiology of Temporomandibular joint Disorder (TMD) may also be influenced by genetic conditions. The current study was aimed to evaluate the hypothesis that the polymorphism of estrogen receptor genes, estrogen receptor 1 and 2 (ESR1 and ESR2), and the gene Catechol-O-Methyl-Transferase (COMT) could be Predisposing factor for TMD.

Methods: In this case-control study, blood sample were taken from 100 TMD diagnosed patients based on Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and 103 healthy individuals as the control group. Tetra ARMS-PCR method was used to amplify and identify COMT rs4680, ESR1 rs1643821, and ESR2 rs1676303 gene polymorphism.

Results: ESR1 genotype AA and GA showed significantly increase probability (OR= 4.80, OR=2.98, respectively) of TMD. ESR2 T/T homozygosity was associated with decreased risk for TMD (OR=0.41). The relationship between COMT and TMD was not statistically significant (p>00.05). The relationship between the severity of TMD and ESR1 was significant (p=0.003). According to the inheritance pattern the COMT and ESR1 gene, in the dominant pattern can be susceptible to TMD and in ESR2 gene, in the recessive pattern can be protective to TMD.

Conclusion: It seems that SNPs of ESR1 rs1643821 has a susceptible role and ESR2 rs1676303 has a protective role against TMD. Also, we add evidences that various genotype of COMT rs4680 were not statistically different between case and control, but allele A in the dominant inherence pattern can be susceptible to TMD.