An SNP in the 5′-UTR of GDF5 is associated with osteoarthritis susceptibility in Europeans and with in vivo differences in allelic expression in articular cartilage

Abstract

A compelling genetic association with osteoarthritis (OA) of a functional SNP (rs143383, T/C) in the 5'-UTR of the GDF5 gene was recently reported in case-control cohorts from Japan and China. GDF5 is a pro-chondrogenic growth factor. The T-allele frequency of the gene was elevated in cases, with an odds ratio (OR) of 1.79, and in vitro functional studies demonstrated that this allele mediated a moderate but significant reduction in the activity of the GDF5 promoter in several cell lines. Our initial objective was to assess whether the SNP was also associated with OA in a broad European population by genotyping the SNP in 2487 cases and 2018 age-matched controls from the UK and Spain. The T-allele was associated with OA (P = 0.03, OR = 1.10) as was carrier status for this allele (P = 0.004, OR = 1.28), demonstrating that the SNP is associated with OA in two diverse ethnic groups, Asians and Europeans. We subsequently assessed the functional effect of the SNP on GDF5 allelic expression using RNA extracted from the cartilage of OA patients who had undergone joint-replacement surgery. The associated T-allele showed up to a 27% reduction in expression relative to the C-allele (P = 0.00007), revealing that the functional effect mediated by SNP rs143383 on GDF5 expression is active in patients who have severe disease up to the point at which they require surgery. A small but persistent imbalance of GDF5 expression throughout life therefore appears to render an individual more susceptible to OA.

Association of Polymorphism in Growth and Differentiation Factor 5 Gene With Osteoarthritis Knee

“…Consistent with the previous reports in Caucasian and Orientals (Miyamoto et al, 2007;Southam et al, 2007), the present study has demonstrated the association between polymorphisms of GDF5 and risk of knee OA in North Indian population and supports the hypothesis that polymorphisms in GDF5 may be involved in the pathogenesis of this disease (Miyamoto et al, 2007). Our data have shown that polymorphism exist in the GDf-5 (BsiE1) gene in North Indian population.…”

“…Our data have shown that polymorphism exist in the GDf-5 (BsiE1) gene in North Indian population. The frequency of T allele in our population (55%) was similar to that reported in Caucasians (59-63 %) (Rouault et al, 2010;Southam et al, 2007;Tsezou et al, 2008;Valdes and Spector, 2009) the oriental population carry relatively higher frequency (70-74%) of variant T allele (Shin et al, 2012;Cao et al, 2010;Dai et al, 2008;Miyamoto et al, 2007).…”

“…Growth and differentiation factor 5 (GDF-5), also known as cartilage derived morphogenetic protein of Transforming Growth Factor-b (TGF-b) superfamily, plays an important role in the development, maintenance and repair of bone and cartilage. It has been shown that reduced transcriptional activity leads to decrease in cartilage synthesis (Francis-West et al, 1999;Hatakeyama et al, 2004;Southam et al, 2007) and to compensate for the cartilage space, the bone beneath thickens and spreads out form knobbly outgrowths (osteophytes).…”

“…The method of (Southam et al, 2007) was followed for determining the GDF-5 gene BSiE1 (T/C; rs143383) polymorphism, In brief, the reaction mixture in 25 µL contained 10X buffer, 1.5mM MgCl 2 , dNTPs (10mM) Science Publications AJBB 0.2 mM , 0.5 µL of 10 pmol of each primer, 1.5U of Taq polymerase (MBI Fermentas, Germany), 100 ng of genomic DNA and sterile MilliQ water. Amplification was performed on GeneAmp PCR system 9700 (Applied Bio System) using the following protocol: 94°C for 5 min for initial denaturation followed by 35 cycles of 94°C for 60 s, annealing at 51°C for 45 s, extension at 72°C for 1min and final elongation step of 72°C for 10 min.…”

Recent advances in association studies of osteoarthritis susceptibility genes

“…28 The most associated SNP (rs143383) is a functional variant, and the susceptibility allele shows decreased GDF5 transcription in vitro and in vivo. [28][29][30] The same allele was reported to be associated with adult height in Caucasians through a GWAS using subjects with non-insulin-dependent diabetes mellitus. 31 Valdes et al 32 assessed rs143383 for OA in the UK Caucasians using 999 knee OA, 843 hip OA and 1166 control samples, and they replicated the association of GDF5 in knee OA (OR¼1.29, 95% CI of 1.14-1.47; P¼8Â10 À5 ).…”