A DAT1 gene and APOE ε4 interaction is associated with apathy and structural brain changes in Alzheimer’s Disease

Abstract Background Apathy in patients with Alzheimer’s disease (AD) is associated with significant morbidity. We examined whether interactions between genetic variants related to neurotransmitter systems and regional brain atrophy are associated with apathy in patients with mild cognitive impairment (MCI) and AD. Method For 1162 participants in the Alzheimer’s Disease Neuroimaging Initiative, including those with AD, MCI and cognitively normal individuals, a partial least squares correspondence analysis (PLS‐CA) modeled interactions between single nucleotide polymorphisms (SNPs), structural whole‐brain imaging variables, and apathy. Result An interaction between apathy, the possession of an APOE (apolipoprotein E) ε4 allele combined with minor homozygosity for the DAT1 (dopamine transporter 1) gene, and brain atrophy. Conclusion The results point to an association of a dopaminergic genetic marker and apathy in AD and may inform future design of clinical trials of apathy, as well as new treatment targets.