Association of Estrogen Receptor-alpha Single-nucleotide Polymorphism (Codon 594 G→→→→→A) and Thai Patients Affected by Knee Osteoarthritis†
Tulyapruek Tawonsawatruk MD*, Objoon Trachoo MD**, Thanaphot Channoom MD*, Thanyachai Sura MD, MRCP**, Jakris Eu-ahsunthornwattana MD, MSc**, Patarawan Woratanarat MD, PhD*, Wiwat Wajanavisit MD*
Affiliation : † Parts of this work have been presented at the 30th Annual Meeting of the Royal College of Orthopedic Surgeons of Thailand during October 22-25, 2008 at Royal Cliff Beach Resort, Pattaya, Chonburi, Thailand. * Department of Orthopedics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand ** Division of Medical Genetics and Molecular Medicine, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
Background : Estrogen receptor-alpha single-nucleotide polymorphism (ER-alpha SNP) has previously shown
its susceptibility to knee osteoarthritis (OA) but this association cannot be applied to ethnic groups with
different genetic backgrounds.
Objective : To characterize the genetic association between ER-alpha SNP and knee OA in the Thai
Material and Method: A case–control study was conducted at Ramathibodi Hospital from August 2007 to
May 2008. Altogether, 104 cases affected by knee OA and 104 controls were included in this study. SNP
rs2228480 (codon 594 G!A) on the ER-alpha gene was genotyped by a PCR-RFLP-based technique. Genotype
frequencies were analyzed by logistic regression.
Results : ER-alpha SNP was normally distributed through the Hardy-Weinberg Equilibrium (HWE). The risk of
knee OA was genetically associated to AG and AA genotypes compared with homozygous wild-type GG (OR:
1.02, 95% CI: 0.60–1.80 for AG; OR: 1.27, 95% CI: 0.30–4.90 for AA).
Conclusion : Our study showed that these genetic alterations might be associated with knee osteoarthritis in
the Thai population. Further investigation on other informative SNPs on the ER-alpha gene should be
performed to create a reliable haplotype that might provide a stronger link between genetic profiles and
clinical picture.
Keywords : Osteoarthritis, OA, Estrogen receptor-alpha, ER-alpha, Single-nucleotide polymorphism, SNP, RFLP, Thai
