To investigate the relationship between knee osteoarthritis (KOA) susceptibility and single nucleotides polymorphism (SNP) of a disinterring and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5) gene.

A total of 188 patients with KOA from Luoyang Orthopedic Hospital were collected as the case group, and 100 patients in the control group were excluded from disease diagnosis. Fifteen SNP of ADAMTS-5 genes were chosen by Genome Variation Server (GVS) online gene database. SNP typing was identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The Hardy-Weinberg equilibrium test was carried out first, chi-square test and Haplotype analysis were carried out on the allele of SNP locus in accordance with the Hardy-Weinberg balance, and then logistic regression analysis was carried out on the genotype.

The C allele of rs2249350 locus in the case group was significantly higher than that in the control group [odds ratios (OR)=1.176, 95% confidence interval (CI) (1.025, 1.351), P=0.0016], the A allele was significantly lower than that in the control group [OR=0.761, 95%CI (0.612, 0.947), P=0.016]. AA genotype [OR=0.288, 95%CI (0.124, 0.669), P=0.004] and recessive gene model [OR=0.348, 95%CI (0.162, 0.749), P=0.007] at rs2249350 locus were negatively correlated with osteoarthritis of the knee joint. There was linkage disequilibrium between the two sites of rs229054 and rs2249350, which formed three single haplotype blocks of GC, GA, and AC. The haplotype GC in the case group was significantly higher than that in the control group [OR=1.259, 95%CI (1.032, 1.537), P=0.019], while the GA in the case group was markedly lower than that in the control group [OR=0.763, 95%CI (0.614, 0.949), P=0.017].

The C allele of rs2249350 site of ADAMTS-5 gene may be the pathogenic factor of knee osteoarthritis, while the A allele may be the protective factor. AA genotype at rs2249350 site may be a protective genotype of osteoarthritis of the knee joint, which reduces the risk of disease, and A allele may be a recessive gene and recessive inheritance. GC haplotype at rs229054 and rs2249350 site may be the pathogenic factor of knee osteoarthritis, while GA haplotype may be a protective factor. The relationship between alleles, genotypes and haplotypes of this site and osteoarthritis of the knee joint still needs to be further studied and verified.