Alzheimer's disease (AD) is a progressive neurodegenerative disorder that is typically initialized by neuronal death in the hippocampus and mediotemporal structures with characteristic episodic memory impairment. However, what is different among AD patients is the age of onset and progression of the disease.
It has been suggested that the major modulators of these factors appear to be genetic polymorphisms in apolipoprotein E (APOE) and brain-derived neurotrophic factor (BDNF) genes. APOE e4 allele is the primary genetic determinant of risk for late-onset AD.
BDNF Val66Met polymorphism has been shown to alter the risk for developing cognitive impairment and disease progression, both directly and indirectly through an interaction with the APOE genotype. The carriage of both risky variants APOE e4/BDNF Met was associated with episodic memory impairment and faster memory decline compared to the presence of only one or none of these high-risk polymorphisms.
This information may be useful for improving the early-detection capability of individuals at risk of developing AD, as well as advancing our understanding of polymorphic combinations that predict the rate of disease progression. Some interventional studies also indicate potential for non-pharmacological interventions in disease prevention in high-risk individuals.