Association between genetic variants of DVWA and osteoarthritis of the knee and hip: a comprehensive meta-analysis.

Recently, double von Willebrand factor domain A (DVWA) gene, a previously unknown gene, was revealed to contain several single nucleotide polymorphisms (SNPs) that showed consistent association with knee osteoarthritis (OA) in Japanese and Chinese cohorts. However, subsequent studies failed to confirm this result in several different populations. To deal with the issues raised by inconsistent results among those studies, we investigated the association between DVWA and OA using meta-analytic techniques, combining all published data up to December 2014. 10 independent samples from 4 teams contributed data for a possible association between SNP rs7639618 and knee or hip OA. The total number of cases and controls of this SNP was respectively 4,142 versus 6,575 for knee OA, and 2,325 versus 2,914 for hip OA. A trend of significant association was observed in the combined population with knee OA (P=0.06), and a significant difference was identified between patients with knee OA and controls for the G-allele of rs7639618 (P=0.02). Together with the reported functional studies, our results indicate that DVWA may have a small but strong effect on the susceptibility to knee OA, at least in Asian population. Further functional studies are needed to determine the underlying variation of DVWA and to relate this to the pathophysiology of OA.