Association of Common Variants in TGFA with Increased Risk of Knee Osteoarthritis Susceptibility

Objective: Osteoarthritis (OA) is a complex degenerative joint disorder, which has contributions from both environmental and genetic factors. Several recent publications have established the connection between hip OA susceptibility and genetic markers within the TGFA gene, however, the relationship of these markers with knee OA has not been elucidated. Therefore, the present study was designed to investigate the potential linkage between common variants of the TGFA gene with knee OA in a large sample of Han Chinese individuals. Methods: We conducted a case-control study, including 338 knee OA patients and 985 unrelated healthy controls using both single nucleotide polymorphism (SNP) markers and haplotype-based analyses to examine the genotypic and allelic distribution of 19 tagging SNPs. Results: We identified a significant association between the SNP rs2862851 and disease status of knee OA (p=0.000314, OR=1.40). Allelic analyses showed that the T allele of this SNP significantly elevated the risks of OA. This result was replicated in genotypic association analyses. In addition, haplotype-based analyses have also identified a strong association signal between one haplotype block, including rs2862851, and the disease status of knee OA (p<0.00001). Conclusion: Our findings suggest that the rs2862851 allele of the TGFA gene may significantly contribute to the susceptibility to knee OA in the Han Chinese population.