Genetic analysis of BDNF and TrkB gene polymorphisms in Alzheimer's disease.

According to previous biochemical and genetic findings, brain-derived neurotrophic factor (BDNF), via activation of its tyrosine kinase receptor B (TrkB), is considered as a plausible candidate for contributing to Alzheimer's disease (AD). To examine the genetic association of BDNF and TrkB genes with AD, we genotyped multiple single nucleotide polymorphisms (SNPs) within these genes among 375 Finnish AD patients and 460 control subjects. Single locus and multi-loci haplotype association analyses of BDNF and TrkB gene SNPs did not reveal significant differences between unstratified AD and control groups. In the case of BDNF SNPs, different allele and haplotype frequencies were observed when 160 sporadic AD cases were compared with 460 control subjects. However, these differences did not remain statistically significant after multiple corrections. We conclude that BDNF and TrkB genes are not contributing significant risk effect among Finnish AD patients.