Association Analysis of Some Polymorphic Variants of Dopaminergic Network Genes (DRD2 rs1800497, DRD4 rs1800955, CNTF rs1800169) with Dopamine and CNTF Levels in Patients with Vibration Disease

Vibration disease (VD) is a chronic occupational disease characterized mainly by damage to the peripheral and central nervous system, including the brain. In the present work, the levels of ciliary neurotrophic factor (CNTF), dopamine and their relationship with polymorphic variants of the G/A gene CNTF (rs1800169), C/T gene DRD2/ANKK1 (rs1800497), T/C gene DRD4 (rs1800955) were evaluated in patients with VD. As a result of the study, an increase in serum CNTF concentrations was recorded relative to the reference values in 55% of patients with VD and dopamine in 41%. It was shown that changes in the levels of studied neurotrophins are associated with polymorphic variants of the genes of the dopaminergic system. In carriers of the C/C genotype of the rs1800955 gene DRD4 polymorphism, increased levels of CNTF and dopamine were observed in 80% of cases. The chance of detecting increased dopamine concentration in VD patients with C/C genotype was 10.7 times greater (OR = 10.7(1.7–65.3)) compared to carriers of the T/T genotype, and 5.7 times higher (OR = 5.7(1.0–31.5)) compared to carriers of T/S genotype. A decrease in CNTF concentration to 2.9 pg/mL and below was noted in 66% of VD patients who were carriers of the T/T genotype of the DRD2/ANKK1 polymorphism (rs1800497). In summary, the study established that polymorphisms rs1800497 of the DRD2/ANKK1 gene and rs1800955 of the DRD4 gene influence serum concentrations of CNTF and dopamine. Specifically, the rs1800497 polymorphism of DRD2/ANKK1 is associated with a decrease in CNTF levels, while the rs1800955 polymorphism of the DRD4 gene is associated with an increase in both CNTF and dopamine. These findings may indicate impairments in neurogenesis and neurotransmitter-receptor interactions, resulting from a combination of genetic factors and epigenetic changes. Further research on larger patient cohorts is necessary for a more detailed assessment of the contribution of genetic factors to the changes in CNTF and dopamine concentrations.