Kashin-Beck disease (KBD) is a chronic endemic osteoarthropathy, which mainly occurs in West and Northeast China. Epidemiological studies suggest that Se deficiency is an important environmental factor for the incidence of KBD. Glutathione peroxidase 4 (GPx4) belongs to the glutathione peroxidase family, which is crucial for optimal antioxidant defences. Our purpose is to investigate the putative association between GPx4 polymorphisms and the risk of KBD. Restriction fragment length polymorphism-PCR was used to detect two SNP (rs713041, rs4807542) in 219 cases and 194 controls in Han Chinese subjects, and quantitative analysis for the GPx4 mRNA level was performed by the real-time PCR method. The results revealed that linkage disequilibrium existed in the two SNP. A significant difference was observed in the haplotype A-T (P = 0·0066) of GPx4, which was obviously lower in the KBD cases (0·006 v. 0·032 %). Correlation analysis based on a single locus showed no association between each SNP and KBD risk. Furthermore, the GPx4 mRNA level was dramatically lower in the blood of KBD patients. Overall, our finding indicated GPx4 polymorphisms and decreased mRNA level may be related to the development of KBD in the Chinese population, suggesting GPx4 as a possible candidate susceptibility gene for KBD.

Kashin-Beck disease (KBD) is an endemic and deformable osteoarthrosis. Epidemiological study has revealed that lower Se level is the principal environmental factor in the pathogenesis of KBD. Selenoprotein P (SEPP1) is a special selenoprotein, which is the primary form of Se in vivo. Our aim was to investigate the putative association of SEPP1 r25191g/a single nucleotide polymorphism (SNP) with KBD risk and the SEPP1 transcriptional levels in whole blood and articular cartilage tissue of KBD cases and controls, respectively. One hundred and sixty-seven cases with KBD and 166 control subjects from Shaanxi province of China were included in the present study. The detection of SNP r25191g/a in the 3′ untranslated region was performed using an efficient technique, tetra-primer amplification refractory mutation system PCR. A quantitative analysis of SEPP1 mRNA in KBD and control groups by real-time PCR was also performed. The present results show no significant difference in genotype and allele distribution of SNP r25191g/a between individuals with KBD and controls (P = 0·279 and 0·428, respectively). There was also no association between SNP r25191g/a and risk of KBD (OR 1·153; 95 % CI 0·533, 2·496). However, the frequency of the rare genotype AG of SNP r25191g/a was significantly lower in Chinese population than in the Caucasians. It was shown that the SEPP1 mRNA expression in whole blood was lower in KBD patients than in the control group (0·149-fold, P < 0·001), but that it was much higher in articular cartilage tissue (4·53-fold, P = 0·012). Our aim was to lay a foundation for us to further study the association between the pathogenesis of KBD and SEPP1.