Brain-derived neurotrophic factor, apolipoprotein E genetic variants and cognitive performance in Alzheimer's disease.

Since greater attention has been paid to the direct link of genetic variation to cognition and memory performance, apolipoprotein E (ApoE) and brain-derived neurotrophic factor (BDNF) have been the two most frequently studied genes. To investigate the effect of BDNF and ApoE polymorphisms on the cognitive profile of mild-moderate Alzheimer's disease (AD) cases, AD patients, genotyped for ApoE and BDNF polymorphisms, underwent extensive neuropsychological investigation. The effect of either ApoE epsilon4 allele and BDNF genetic variant on the neuropsychological pattern of mental impairment was examined both in terms of group differences in performance on the neuropsychological tests between carriers and non-carriers of each variant and by selecting the best predictor of cognitive performance among demographic and genetic factors by means of a multiple regression analysis. Our data confirm a specific effect caused by the presence and amount of ApoE epsilon4 allele, while they suggest that BDNF genetic variants are not a susceptibility factor to AD.