Genetic Contribution to the Development of Radiographic Knee Osteoarthritis in a Population Presenting with Nonacute Knee Symptoms a Decade Earlier

Association between GDF5 single nucleotide polymorphism rs143383 and lumbar disc degeneration

The association between growth differentiation factor 5 (GDF5), single nucleotide polymorphism (SNP) rs143383 and lumbar disc degeneration (LDD) was investigated. A total of 210 patients with LDD (observation group) and 320 patients without lumbar diseases (control group) diagnosed in Shanghai General Hospital of Nanjing Medical University from August 2013 to March 2017 were randomly selected. Then, deoxyribonucleic acid (DNA) was extracted from the blood of each patient, and Taq-man fluorescent quantitative polymerase chain reaction (qPCR) technique was used to detect rs143383 in GFD5 gene. The frequency of different genotypes in observation group and control group was counted, and the associations between different SNP genotypes and the incidence of LDD were analyzed. Good genotyping results were found in both LDD patient group and control group. There were no significant differences in distribution frequency of TT and TC genotypes at site rs143383 between LDD patient group and control group (P>0.05), but the distribution frequency of CC genotype at site rs143383 in LDD patient group had a statistically significant difference from that in control group (P<0.05). In dominant models, odds ratio (OR) of (TC+CC/TT) was 1.195 (P=0.532). In recessive models, OR of (CC/TT+TC) was 4.333 (P=0.028). In co-dominant models, ORs of (TC/TT) and (CC/TT) were 0.967 and 4.43, respectively (P=0.99). The differences in 3 genotypes showed no statistical significance among different pathological grades (Grade I to V) (χ²=1.034, P=0.998), and there was no statistically significant difference in T and C (χ²=0.012, P=0.999). Pathological grades in dominant models, recessive models and over dominant models were analyzed, and no statistically significant difference was found (P>0.05). In conclusion, CC mutant type at rs143383 in GDF5 gene has a strong association with the incidence of LDD, and a high prevalence risk, but it has no evident correlation with pathological grades.

IL1R1 gene polymorphisms are associated with knee osteoarthritis risk in the Chinese Han population

IL1R1, encoding interleukin 1 receptor type 1, is located in the IL-1 gene cluster and is involved in the pathogenesis of hand, hip, and knee osteoarthritis (OA) in different ethnicities. However, the link between IL1R1 polymorphisms and OA risk in the Chinese Han population is unknown. We studied the association between five IL1R1 polymorphisms (rs10490571, rs12712127, rs956730, rs3917225, and rs3917318) and OA risk by analyzing the genotypes of 298 knee OA patients and 297 controls using Sequenom MassARRAY technology. Logistic regression analysis after adjusting for gender and age revealed significant differences in the allele frequencies of IL1R1 rs956730 and IL1R1 rs3917225 between patients and controls. In addition, IL1R1 rs3917225 was associated with increased risk of knee OA with or without adjustment by age and gender in the dominant model (adjusted OR= 1.47, 95%CI: 1.04-2.07, P = 0.030), the recessive model (adjusted OR= 1.75, 95%CI: 1.08-2.85, P= 0.023), and the additive model (adjusted OR= 1.40, 95%CI: 1.09-1.79, P = 0.007). This study is the first to report that IL1R1 polymorphisms are associated with knee OA susceptibility in the Northwestern Chinese Han population.