Association Of MMP9 And MMP2 Polymorphism With Susceptibility To Non-traumatic Osteonecrosis Of Femoral Head In A Chinese Han Population Of Northern China

Background: Non-traumatic osteonecrosis of the femoral head(ONFH)is is a painful and progressive disorder of the hip joint,mainly affecting middle aged individuals 30-50 years old in Chinese Han population.Matrix metalloproteinase(MMPs)produced by osteoblasts and osteoclasts have been implicated in the degradation of extracellular matrix(ECM)and basement membranes(BMs)during bone development.The aim of our study was to identify the associations between 8 selected genes from the MMP9 and MMP2 and non-traumatic ONFH.Materials and methods: In the case-control study,we examined 8 single-nucleotide polymorphisms(SNPs),which were previously-identified related to other diseases,in the MMP9 and MMP2 genes of 585 non-traumatic ONFH patients and 507 controls from northern China to determine whether these SNPs are associated with the risks of developing non-traumatic ONFH.Result: Chi-squared tests,genetic model and haplotype analyses are used to evaluate the association between SNPs and non-traumatic ONFH.After adjusting for age and gender,it shows the SNP rs2274755 in MMP9 is associated with a decreased risk of non-traumatic ONFH in the dominant model(OR=0.71,95%CI: 0.52-0.92,p=0.011)and log-additive model(OR,0.740;95% CI,0.56-0.94;P = 0.013).Additionally,the “TGC” haplotype in rs2274755 was associated with a 0.79-fold decrease in the risk of non-traumatic ONFH,and the “CTC” haplotype is with a 0.65-fold decrease risk.Conclusion: These results provide evidence that MMP9 at the SNP(rs2274755)locus is associated with a decreased risk of non-traumatic ONFH in Chinese Han population.