Evaluation of Relationship Between Common Variants in FGF18 Gene and Knee Osteoarthritis Susceptibility

Abstract

Osteoarthritis (OA) is the most common type of arthritis disease. Previous etiological studies indicated that both environmental and genetic factors play important roles in the occurrence and development of knee OA (KOA). In the present study, we aimed to investigate the association between the FGF18 gene and susceptibility to KOA in Han Chinese population. A total of 2,556 unrelated Han Chinese individuals, including 866 KOA patients and 1,688 healthy controls, were recruited. Nine tag SNPs located within the gene region of FGF18 were selected for genotyping. Logistic models were fitted for single marker-based association analyses. Age, gender and BMI were included in each model as covariates. To investigate the functional consequences of significant SNP, we extracted expression quantitative trait loci (eQTL) data from the GTEx database. SNP rs3884606 was significantly associated with the risk of KOA (OR [95% CI]=1.25 [1.11-1.41], p=0.0002) after adjusting for age, gender and BMI. The G allele was significantly associated with an increased risk of KOA. No significant eQTL signals could be identified for SNP rs3884606 on FGF18. In this study, we identified a genetic polymorphism in FGF18 that was significantly associated with the risk of KOA based on samples with Chinese Han ancestry. Our findings replicated the recent GWAS report and supported an association between KOA and FGF18.