Association of Polymorphic Variants of Brain-Derived Neurotrophic Factor Gene (Bdnf Rs6265) and Glutamate Transporter Gene of the Second Type (Slc1a2 Rs4354668) with the Course of Multiple Sclerosis in Patients Living in Tomsk Region

Background: Multiple sclerosis (MS) is an autoimmune disease of the central nervous system that affects people of working age and ultimately leads to disability. This disease is of polygenic origin. The role of factors related to the pathogenesis of the disease and affecting both neuroinflammation and remyelination is studied. Aims: Our goal was to investigate the association of single nucleotide polymorphisms BDNF rs6265 and SLC1A2 rs4354668 with the risk of occurrence, clinical manifestations and the course of MS.

Materials and methods: The study included 302 patients with MS, 268 healthy volunteers were enrolled in a control group. The obtained blood was used for DNA extraction by standard phenol-chloroform method. The identification of allelic variants of genes SLC1A2 (rs4354668) and BDNF (rs6265) was performed by polymerase chain reaction.

Results: When comparing the frequencies of genotypes and alleles of polymorphic variants of BDNF and SLC1A2 genes between the groups of MS patients and the control group, no statistically significant differences were revealed. Comparison of genotype and allele frequencies of patients depending on sex, age of onset of the disease also did not reveal statistically significant differences. The study of the association of polymorphic variant of the gene BDNF (rs6265) with clinical manifestations of the disease revealed the association of genotype CC with oculomotor and trigeminal disorders at the onset of the disease (F=7, p=0.017). The study of the polymorphic variant rs4354668 of the glutamate transporter gene SLC1A2 revealed the association of allele G with an earlier (within 5 years from the moment of debut) transition of the disease to the stage of secondary progression, despite the therapy with DMT (χ²=5.940; p=0.010; OR 1.58; 95% CI 1.09−2.29). Homozygous genotype of TT (χ²=6.393; p=0.041; OR 0.50; 95% CI 0.28−0.88) and allele T (χ²=5.940; p=0.010; OR 0.63; 95% CI 0.44−0.92) of the polymorphism rs4354668 of the glutamate transporter gene SLC1A2 are significantly more common in the group of patients with late transition (15 years or more from the moment of debut) to the secondary progressive course.

Conclusions: In our study we revealed the relationship of the studied polymorphic variants of genes with clinical signs at the onset of the disease and with the clinical manifestations of MS in patients living in the Tomsk region.