Association Between The Genes Polymorphisms In BDNF Signal Pathways And Personality In The Recovered Patients With Depression

Objective:To explore the genes such as BDNF,PKB1,GSK-3B and PRKCG in brain-derived neurotrophic factor (BDNF) pathways, and search for the interaction effects among them on the personality in Chinese North Han the recovered patients with depression.Methods:From Match 2008 to August 2009, Into the study group we included 200 depressive patients undergoing the following up treatment,finally 124 patients recovered, All subjects were assessed by Eysenck Personality Quesrionnaire (EPQ) including three personality dimensions:Neuroticism(N), Introversion-Extraversion(E) and Psychoticism(P). We calculated the standard scores (T) of three dimensions, and then divided N, E dimensions into three levels by the T38.5-61.5:Non-neuroticism, moderate and Neuroticism; Introversion, moderate and Extraversion; divided P dimensions into two levels by the T61.5:Psychoticism and Non-psychoticism. Six single nucleotide polymorphisms (SNPs) of BDNF pathways genes were detected by polymerase chain reaction (PCR), including rs6265 and rs7124442 in BDNF gene, rs2494746 and rs2494738 in PKB1 gene, rs6782799 in GSK-3B gene, and rs3745406 in PRKCG gene. SPSS 13.0 software were used for monofactorial analyses:Personality means were compared with t-test and One-Way ANOVA, the genotypic and allelic frequency distribution were compared withχ2 analysis; UNPHASED program were used to perform the gene-gene interaction analysis among SNPs.Results:1. General demography data analysis There were no significant difference in distributions of mean age, sex and educational background between different personality groups(P>0.05).2. Hardy-Weinberg equilibrium testThe goodness-of-fitχ2 test for Hardy-Weinberg equilibrium showed that the genotypic distributions of 5 SNPs (rs6265 and rs7124442 in BDNF gene, rs6782799 in GSK3B, rs2494746 in PKB1 and rs3745406 in PRKCG) in this sample were in HWE (P>0.05), which indicated that the sample can represent the population. Except rs2494738 in PKB1 has significantly difference in the Hardy-Weinberg equilibrium (P<0.05), and was cancelled from following analysis.3. Single gene analyses3.1 BDNF rs7124442 ①No statistically significant difference of each personality dimension mean was detected between different rs7124442 genotypes and alleles(P>0.05).②There was no significant difference of rs7124442 genotypes and alleles frequency distribution between different personality dimension groups(P>0.05).3.2 BDNF rs6265①The difference of N personality dimension mean was statistically significant between different rs6265 genotypes (P<0.05). N dimension mean with allele A (62.22±9.43) was lower than that with allele G(59.37±11.90), which was statistically significant(t=2.426, P=0.016), but it showed no significant after Bonferroni correction(P>0.05). N,P dimensions mean was not statistically significant between rs6265 genotypes (P>0.05).②The frequency distribution of rs6265 allele A in introversion group (49.7%) was more than no introversion group(35.0%), which was significant (χ2=7.449, P=0.023), but it showed no significant after Bonferroni correction(P>0.05).3.3 PRKCG rs3745406①No statistically significant difference of each personality dimension mean was detected between different rs3745406 genotypes and alleles(P>0.05).②There was no statistically significant difference of rs3745406 genotypes and alleles frequency distribution between different personality dimension groups(P>0.05).3.4 GSK-3B rs6782799①No statistically significant difference of each personality dimension means was detected between different rs6782799 genotypes and alleles(P>0.05).②There was no statistically significant difference of rs6782799 genotypes and alleles frequency distribution between different personality dimension groups (P>0.05).3.5 PKB1 rs2494746①No statistically significant difference of each personality dimension means was detected between different rs2494746 genotypes and alleles(P>0.05).②There was no statistically significant difference of rs2494746 genotypes and alleles frequency distribution between different personality dimension groups (P>0.05).4. Interaction effects gene-gene analysisUNPHASED results showed that the significant interaction effects were detected for the BDNF rs6265-PRKCG rs3745406 combination (χ2=8.016,P=0.024) in Neuroticism personality dimension. But it showed no significant after 1000 times repeating by the permutation testing.The others combination have no significant interaction in the E and P personality dimension(P>0.05).Conclusions: 1. No significant associations were found between BDNF,PKB1,GSK-3B,PRKCG single gene and EPQ personality in Chinese Han the recovered patients with depression.2. No interaction effects were detected including the between with BDNF rs6265,PRKCG rs3745406,GSK-3B rs6782799 and PKB1 rs2494746 on EPQ personality in Chinese Han the recovered patients with depression.