Effects of BDNF and COMT variants on cognitive decline in Early‐Onset Alzheimer’s Disease

Background Early‐Onset Alzheimer’s Disease (EOAD) is a rare condition that affects only 5% of patients with Alzheimer’s Disease (AD). At present, only basic information is known about the impact of AD risk variants on EOAD, and the effects of more subtle genetic contributions to cognitive decline have yet to be investigated. Genetic variants for brain derived neurotrophic factor (BDNF) and catechol‐O‐methyltransferase (COMT) have both been implicated in cognitive change (Fiocco et al., 2010; Ferrer et al., 2019), consequently the aim of the current study was to examine the role of these genetic variants on cognitive decline in EOAD. Method Data from 88 amyloid‐positive EOAD participants enrolled in the Longitudinal Early Onset Alzheimer’s Disease Study (LEADS; aged 40‐64) were analyzed. Exploratory multivariate analyses of covariance (MANCOVA) were conducted to investigate differences in 12‐month cognitive decline as a function of BDNF rs6265 (p.V66M) and COMT rs4680 (p.V158M) variants using dominant genetic models (Val/Val versus Val/Met or Met/Met). Cox Regression analyses were also conducted to consider the effect of genetic variants on age of onset. Result See Table 1 for demographic characteristics of our sample. MANCOVA, controlling for age, education, sex, and race/ethnicity, showed significant effects for BDNF p.V66M on domains of Memory (p