Association Study Of Brain-derived Neurotrophic Factor (bdnf) Haplotype And Apolipoprotein E (apoe) Gene Polymorphism In Late-onset Depression

ObjectiveThe aim of the present study was to identify the genotype and allele frequencies of susceptible genes involving in BDNF and APOE in a Chinese Han population, verify and explore the relationship between BDNF haplotypes and late-onset depression (LOD) and to develop approaches for early diagnosis, further understanding pathogenic mechanism of LOD.MethodsCase-control study and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method were used to detect the polymorphisms of APOE, BDNF 712G/A, BDNF 270C/T, BDNF 196A/G and BDNF 11757G/C in 144 LOD patients and 110 healthy controls. The software SHEsis was used to analyze the linkage disequilibrium and haplotypes between the two groups.Results1. The distribution of APOE genotypes followed Hardy-Weinberg equilibrium among LOD patients and control subjects (P>0.05 for each comparison). Our data showed that the distribution of APOE alleles and genotypes were not significantly different in patients compared with controls..2. The distribution of BDNF 712G/A, 270C/T, 196A/G, BDNF 11757G/C genotypes followed Hardy-Weinberg equilibrium among patients and control subjects (except for 11757G/C in patients). The current study did not demonstrate any significant difference in genotypes and alleles frequencies between patients and controls.3. The presence of 712G-270T, 196A-11757G, 196G-11757C haplotypes was higher in patients compared to controls. The other haplotypes did not show significant difference between patients and controls.4. The presence of 712G-196A-11757G, 712G-196G-11757C, 270C-196A- 11757G, 270C-196G-11757C haplotypes was higher in patients compared to controls. The other haplotypes did not show significant difference between patients and controls.5. The presence of 712G-270C-196A-11757G, 712G-270C-196G-11757C haplotypes was higher in patients compared to controls. The other haplotypes did not show significant difference between patients and controls.6. APOEε4 allele interacted with BDNF 712G/A BDNF 270C/T, BDNF 196A/G, BDNF 11757G/C did not significantly increase the risk with late-onset depression.Conclusions1. The BDNF 712G-270T, 196A-11757G, 196G-11757C,712G-196A-11757G, 712G-196G-11757C, 270C-196A-11757G, 270C-196G-11757C, 712G-270C-196A- 11757G, 712G-270C-196G-11757C haplotypes might be the risk markers for LOD.2. APOE SNP did not show to be a risk factor for LOD.3. APOEε4 allele interacted with BDNF 712G/A BDNF 270C/T, BDNF 196A/G, BDNF 11757G/C did not serve as the risk marker for LOD.