The role of candidate gene polymorphisms in the risk of vertebrogenic disorders under combined exposure to occupational vibration and heavy physical labor

This study conducted a molecular genetic analysis of polymorphisms in three genes involved in regulation of the inflammatory response and connective tissue remodeling in relation to development of spinal pathology. The aim of the study was to investigate the associations of the polymorphic loci rs361525 of the TNF-α gene, rs1800795 of the IL-6 gene, and rs7163797 of the SMAD3 gene with the risk of developing vertebrogenic disorders in workers under combined exposure to occupational vibration and heavy physical labor. The study included 118 patients with vertebrogenic disorders and 77 controls. Genotyping was performed using realtime polymerase chain reaction. Statistical analysis was performed using Fisher's exact test, the χ2 test, odds ratio (OR), and 95 % confidence interval (CI). A significant association was found between the rs361525 polymorphism of the TNF-α gene and the risk of vertebrogenic disorders. The frequency of the A allele was significantly higherin the patient group (19.8 % versus 7.8 % in the control; p = 0.001; OR = 2.93; 95 % CI: 1.50–5.73). The A/A genotype was also significantly more common among patients (12.1 % versus 0 %; p = 0.001). An association was revealed between the C/C genotype of the rs1800795 polymorphism of the IL-6 gene and an increased risk of vertebrogenic disorders (24.1 % vs. 12.0 % in the control; p = 0.038; OR = 2.334; 95 % CI: 1.032–5.278). No significant differences in the distribution of allele and genotype frequencies were found between the groups for the rs7163797 polymorphisms of the SMAD3 gene. The A allele and homozygous A/A genotype of the rs361525 polymorphism of the TNF-α gene, as well as the C/C genotype of the rs1800795 polymorphism of the IL-6 gene, can be considered potential markers of increased risk of developing vertebrogenic disorders in the studied population. Polymorphism of the SMAD3 gene does not appear to make independent significant contributions to predisposition to these conditions. These results expand our understanding of the molecular genetic basis of spinal pathology and require confirmation in larger, independent samples.