Lack of association between the CALM1 core promoter polymorphism (-16C/T) and susceptibility to knee osteoarthritis in a Chinese Han population

<p>Abstract</p> <p>Background</p> <p><it>CALM1 </it>gene encodes calmodulin (CaM), an important and ubiquitous eukaryotic Ca²⁺-binding protein. Several studies have indicated that a deficient CaM function is likely to be involved in the pathogenesis of osteoarthritis (OA). Using a convincing genome-wide association study, a Japanese group has recently demonstrated a genetic association between the <it>CALM1 </it>core promoter polymorphism (-16C/T transition SNP, rs12885713) and OA susceptibility. However, the subsequent association studies failed to provide consistent results in OA patients of differently selected populations. The present study is to evaluate the association of the -16C/T polymorphism with knee OA in a Chinese Han population.</p> <p>Methods</p> <p>A case-control association study was conducted. The polymorphism was genotyped in 183 patients who had primary symptomatic knee OA with radiographic confirmation and in 210 matched controls. Allelic and genotypic frequencies were compared between patients and control subjects.</p> <p>Results</p> <p>No significant difference was detected in genotype or allele distribution between knee OA and control groups (all <it>P </it>> 0.05). The association was also negative even after stratification by sex. Furthermore, no association between the -16C/T SNP genotype and the clinical variables age, sex, BMI (body mass index) and K/L (Kellgren/Lawrence) score was observed in OA patients.</p> <p>Conclusion</p> <p>The present study suggests that the CALM1 core promoter polymorphism -16C/T is not a risk factor for knee OA susceptibility in the Chinese Han population. Further studies are needed to give a global view of this polymorphism in pathogenesis of OA.</p

Association of the leptin gene with knee osteoarthritis susceptibility in a Han Chinese population: A case-control study

Previous studies have suggested that leptin works as a key regulator in the pathogenesis of osteoarthritis (OA), and genetic factors modulate OA. This study assessed the contribution of leptin gene (LEP) polymorphism(s) to knee OA among Han Chinese. Three tag single-nucleotide polymorphisms (SNPs) covering all those LEP SNPs of which the minor allele frequencies were over 10% were selected. Study subjects (697 patients and 699 controls) were divided into four groups (underweight, normal weight, overweight and obese) by body mass index (BMI). Allele and genotype frequencies in the three tag SNPs were significantly different in the normal weight and overweight groups. In the normal weight, overweight and obese groups, BMI (P=4.3 × 10-5, 0.012 and 0.009, respectively) and gender (P=3.5 × 10-22, 5.1 × 10-23 and 2.1 × 10-8, respectively) were effective factors. Age was an independent effective factor in the overweight group (P=0.009). Haplotypes were associated with OA in the normal weight group (CAT, P=0.015) and the overweight group (AGC, P=0.015). Our results suggest an association between LEP and knee OA in the normal weight and overweight groups among Han Chinese. © 2010 The Japan Society of Human Genetics All rights reserved