The single nucleotide polymorphism (SNP) of the estrogen receptor-β gene, rs1256049, is associated with knee osteoarthritis in Korean population

Background: Estrogens affect articular cartilage metabolism via estrogen receptors (ER) in chondrocytes and are believed to play an important role in the pathophysiology of osteoarthritis (OA). The aim of this study is to determine whether the single nucleotide polymorphism (SNP) of the estrogen receptor-beta (ER-beta) is associated with an increased susceptibility to knee OA. Methods: The possible influence of the SNP of the ER-beta was investigated in 286 OA patients and 294 healthy subjects as controls. A polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) assay and a PCR-single strand conformation polymorphism (SSCP) assay were used to identify the Rsa polymorphism genotype among healthy controls and OA patients, respectively. Results: For rs1256049 (Rsa), frequencies of genotypes GG, GA, and AA were 49.0% (144/294), 43.5% (128/294), and 7.5% (22/294) in healthy controls, and 35.3% (101/286), 45.5% (130/286), and 192% (55/286) in OA patients. Frequencies of alleles G and A among healthy controls were 70.7% (416/588) and 29.3% (172/588); whereas those among OA patients were 58.0% (332/572) and 42.0% (240/572). Statistically significant differences in allele and genotype frequencies of rs1256049 were observed between OA patients and controls (P<0.0001). In particular, the risk of OA was significantly increased in carriers with the rs1256049A allele and rs1256049 AA homozygotes. Conclusions: These results suggest a close association of rs1256049 ER-beta polymorphisms with susceptibility to OA in the Korean population. Clinical relevance: The rs1256049 polymorphism of the estrogen receptor-p gene can potentially be used to identify genetically high-risk subgroup of osteoarthritis in advance and to understand pathogenesis of osteoarthritis. (C) 2013 Elsevier B.V. All rights reserved.