Objectives: To evaluate the role of COMT gene variants as potential risk factors in a group of patients affected with chronic temporomandibular disorder (TMD) pain.
Methods: We sequenced COMT gene in 182 Italian subjects (50 affected by TMD and 132 controls). The study population consisted of patients affected by myogenous and/or arthrogenous pain (RDC/TMD: Ia, Ib, IIIa, IIIb diagnostic categories).
Results: We detected 40 single nucleotide polymorphisms (SNPs) variants (18 novel). Three SNPs, all located in the promoter regions, were more frequently present in cases than in controls (rs 4646310 P=0.018, rs165656 P=0.001, rs 165722 P=0.007). After the False Discovery Rate (FDR) correction rs165656 remained significantly associated with TMD (P=0.049). In addition, the rs 4646310 (AG vs GG, P=0.015) and rs 165656 (GG vs CC, P=0.001) were at binary logistic regression analysis independently associated with TMD, conferring a risk disease of 2.6 (CI= 1.2-5.6) and of 5.3 (CI= 2.0-13.7) respectively.
Discussion: Our data extend the number of SNPs present in the promoter region that could play a regulatory role in COMT gene and suggest that the genetic polymorphisms rs 165656 and rs 4646310 exert a role in TMD susceptibility.