Association study of the candidate gene for knee osteoarthritis in Koreans.

The aim of this study was to examine a single-nucleotide polymorphism (SNP) rs7639618 of double von Willebrand factor (DVWA) gene for the association with osteoarthritis (OA) susceptibility in Korean cohort. The study was a part of the Korean cohort study. Two thousand four hundred sixty-two subjects aged 50 years and older who were derived from the cohort and who were assessed for OA at the knee were genotyped. The anteroposterior extended-view weight-bearing radiographs of the knees were obtained. Of the subjects, 725 subjects had radiographic OA. Genomic DNA was extracted from peripheral blood using a QIAamp DNA Blood Mini Kit (Qiagen, Valencia, CA). Genotyping was performed using High Resolution Melt or the Taq-Man allelic discrimination assay and the Rotor-Gene 6000 (Corbett Research, Sydney,Australia). Associations were tested by calculating the odds ratios (ORs) and 95% confidence intervals (95% CIs), using logistic regression analysis with adjustments for age, gender, and body mass index (BMI). The mean age of the OA patients (females: 554 subjects, 76.4%) was 67.4 (7.9) years. The intraobserver agreement was high for the identification of osteophytes (κ: 0.80) and joint space narrowing (κ: 0.70). There was no significant difference (all P values > 0.05) in the genotype or allele frequencies between the patients with OA and healthy controls. There was also no significant difference when the cases were adjusted by age, gender, and BMI. The associations of DVWA SNPs with OA were noted in previous studies and were not found in the Korean OA cohort.