Association of the CALM1 Core Promoter Polymorphism with Knee Osteoarthritis in Patients of Greek Origin

Abstract

Osteoarthritis (OA) is characterized by focal areas of loss of articular cartilage in synovial joints, associated with varying degrees of osteophyte formation, subchondral bone change, and synovitis. The Calmodulin 1 gene (CALM1) encodes for a ubiquitous eukaryotic Ca2+ binding protein and is the principal mediator of the calcium signal. The protein thus affects the chondrocyte's response to mechanical load. A functional core promoter single nucleotide polymorphism (SNP) -16C/T (rs12885713) was recently associated with hip OA (HOA) in the Japanese population, while no association was found in a British group of patients with HOA. Our objective was to assess whether this SNP was also associated with knee OA (KOA) in a Greek Caucasian population sample. The -16T/C SNP was genotyped in a 351 case-control cohort--158 patients with idiopathic KOA and 193 controls. No significant differences were found in genotype frequencies for the -16T/C SNP of CALM1 gene between cases and controls (p = 0.581). Our data implied that the -16TT (rs12885713) CALM1 core promoter genotype is not a risk factor for OA etiology in Greek Caucasians on its own, but associated with the Asporin (ASPN) D14 or D15 risk allele, it could influence KOA susceptibility.