Association between Single-Nucleotide Polymorphisms of the Tyrosine Kinase Receptor B (TrkB) and Post-Stroke Depression in China

BACKGROUND Polymorphisms of the brain-derived neurotrophic factor (BDNF) have been investigated as candidate genes for post-stroke depression (PSD), and its receptor, neurotrophic tyrosine kinase receptor B (TrkB), has been associated with depression. However, no further data have yet reported the association between PSD and polymorphisms in TrkB. This study aims to investigate whether a relationship exists between TrkB polymorphisms and PSD. METHODS A total of 312 depression patients (PSD patients) and 472 non-depression patient controls (NPSD patients) were recruited. All patients were evaluated using the Hamilton Rating Scale for Depression (HAMD) to determine depression severity, and PSD patients were diagnosed in accordance with DSM-V criteria. Three single-nucleotide polymorphisms (SNPs), namely, rs1187323, rs1212171, and rs1778929, in the TrkB gene were genotyped by high-resolution melt analysis. RESULTS The SNP rs1778929 was significantly more associated with incident PSD in participants with the TT genotype than in those with CC (OR 0.482, 95% CI: 0.313-0.744). In terms of rs1187323, stroke was significantly more associated with incident depression in participants with the AC genotype than in those with AA (OR 0.500, 95% CI: 0.368-0.680). The minor allele (T) of rs1778929 (P = 0.024, OR = 0.725, 95% CI = 0.590-0.890) and the minor allele (C) of rs1187323 (P = 0.000, OR = 0.598, 95% CI = 0.466-0.767) were found to be significantly associated with PSD. Neither genotype nor allele frequencies of rs1212171 showed statistically significant differences between PSD and NPSD patients. CONCLUSIONS The results suggest that rs1778929 and rs1187323 in the TrkB gene are significantly associated with post-stroke depression in the Chinese population. Further studies are necessary to confirm our findings.