A single-nucleotide polymorphism in MMP9 is associated with decreased risk of steroid-induced osteonecrosis of the femoral head

Abstract

Osteonecrosis of the femoral head (ONFH) is a common hip joint disease, and steroid-induced ONFH accounts for a large number of cases. Here, we examined eight previously-identified single-nucleotide polymorphisms (SNPs) in the MPP2 and MPP9 genes of 285 steroid-induced ONFH patients and 507 healthy controls from northern China to determine whether these SNPs were associated with the risk of developing steroid-induced ONFH. Chi-squared tests and genetic model and haplotype analyses were used to evaluate associations. The rs2274755 SNP in MMP9 was associated with a decreased risk of steroid-induced ONFH in the allele, dominant, and additive models. Additionally, the "CGC" MMP9 haplotype was associated with a 0.69-fold decrease in the risk of steroid-induced ONFH. Although additional, larger population-based studies are needed to confirm these findings, our results reveal for the first time an association between a MMP9 SNP at the rs2274755 locus and a decreased risk of steroid-induced ONFH in a northern Chinese population.

Keywords: MMP2; MMP9; association study; osteonecrosis of the femoral head; single nucleotide polymorphisms.

Figure 1. Linkage disequilibrium (LD) plots containing three SNPs from MMP9

Red squares display statistically significant associations between a pair of SNPs, as measured by D'; darker shades of red indicate higher D'

Figure 2. Linkage disequilibrium (LD) plots containing five SNPs from MMP2

Red squares display statistically significant associations between a pair of SNPs, as measured by D'; darker shades of red indicate higher D'.