Estrogen receptor-alpha polymorphism in patients with and without degenerative disease of the temporomandibular joint

AIMS: The genetic aspect of degenerative joint disease (DJD) of the temporomandibular joint is poorly understood. The prevalence of the estrogen receptor alpha (ER-alpha) gene polymorphism in patients with and without DJD using xbal and pvull restriction fragment length polymorphisms (RFLPs) was studied. METHODOLOGY: DNA samples from 42 DJD⁺ and 36 DJD⁻ subjects were amplified. A 346-base pair long ER-alpha gene fragment containing the two sites of polymorphism in intron 1 was analyzed for xbal and pvull RFLP. Statistical analysis was carried out using Fisher's exact test and two-group t-test. RESULTS: Five different ER-alpha genotypes were found in both groups. These were PXPX, pxpx, pxPX, PxPX, and pxPx. DISCUSSION: There was a higher number of pxpx and pxPX genotypes in the DJD⁺ samples compared to the DJD⁻ group, which suggests the presence of polymorphism possibly modulates the ER-alpha activity in bone and contributes to the degenerative process in the joint.