Polymorphic Variants of Neurotrophic Factor Genes in Affective Disorders: Pilot Study

Neurotrophic factors are regulatory proteins of nervous tissue. They have a significant effect on all processes in neurons. Neurotrophic factors participate in the processes of neuronal differentiation, neurogenesis, synaptogenesis, and the regulation of neuronal plasticity. Numerous data in the literature indicate that disruption of the regulation of neurotrophic factors can play an important role in the etiology of affective disorders. We examined 235 patients with an affective disorder (F31, F32, F33, F34.1, ICD-10) and 187 healthy controls. The mental state of the patients was assessed by SIGH-SAD, HARS, and CGI scales. Genotyping of polymorphic variants of neurotrophic factor genes (BDNF, NGF, and NRG1) was performed using real-time PCR. Only one of the polymorphisms (rs7124442 in the BDNF gene) showed an association with the affective disorders. All polymorphisms (except rs11030104 in the BDNF gene) showed an association or associated trend with clinical characteristics of the disease, evaluated according to psychometric scales and response to therapy. Our results support the potential value of the studied neurotrophic genes as a neurobiological marker for depression pathogenesis, clinical characteristics, and response to treatment. Due to several limitations, further case-control studies with larger sample sizes and different ethnic groups are needed.