The rs2030324 SNP of brain-derived neurotrophic factor (BDNF) is associated with visual cognitive processing in multiple sclerosis

Purpose: To investigate the associations between the rs2030324 SNP of brain-derived neurotrophic factor (BDNF) and neuropsychological (NP) test measures in multiple sclerosis (MS) patients. Background: BDNF regulates the survival of neuronal and non-neuronal cells and plays a critical role in neurochemical processes underlying learning and memory. Methods: A total of 209 MS patients (161 females; 48 males) underwent brain MRI and genotyping for BDNF rs2030324. The NP testing (n = 108) assessed processing speed, working memory, new learning and executive control. The MRI measurements included T1 and T2 lesion volume, whole brain, white and gray matter volumes, magnetization transfer imaging and regional subcortical brain volumes. Results: The T/T rs2030324 genotype group performed poorly on the Brief Visuospatial Memory Test-Revised (p = 0.031) and the Symbol Digit Modalities Test (p = 0.045) compared to the C/C genotype group. Because these NP tests both involve visual processing, the relationship with the volume of the thalamus was assessed. The BDNF rs2030324 genotype was associated with the volume of the left thalamus (p = 0.036). There were no significant associations with whole brain lesional and atrophy MRI measures. Conclusions: The C allele of BDNF rs2030324 is associated with protection against visual cognitive processing deficits via mechanisms that appear associated with the volume of the thalamus.