To evaluate the role of COMT gene variants as potential risk factors in a group of patients affected with chronic temporomandibular disorder (TMD) pain.
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).
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.
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.