Data from: ApoE is a correlate of phenotypic heterogeneity in Alzheimer’s disease in a national cohort

Objective: To compare the proportion of APOEε4 genotype carriers in
aphasic versus amnestic variants of Alzheimer’s disease (AD). Method: The
proportion of APOEε4 carriers was compared among 3 groups. 1) Forty-two
patients with primary progressive aphasia (PPA) and AD pathology (PPA/AD)
enrolled in the Northwestern Alzheimer Disease Center Clinical Core. 2)
1,418 patients with autopsy confirmed AD and amnestic dementia of the
Alzheimer-type (DAT/AD); 3) 2,608 cognitively normal controls (NC). The
latter two groups were compiled from the National Alzheimer Coordinating
Center (NACC) database. Logistic regression models analyzed the
relationship between groups and APOEε4 carrier status, adjusting for age
of onset and sex as needed. Results: Using NC as the reference and
adjusting for sex and age, the DAT/AD group was 3.97 times more likely to
be APOEε4 carriers. Adjusting for sex and age at symptom onset, the DAT/AD
group was 2.46 times as likely to be carriers compared to PPA/AD. There
was no significant difference in the proportion of APOEε4 carriers for
PPA/AD compared to NC. PPA subtypes included 24 logopenic, 10 agrammatic
nonfluent, and eight either mixed (n=5) or too severe (n=3) to subtype.
The proportion of carriers and non carriers was similar for logopenic and
agrammatic subtypes, both having fewer carriers. Conclusion: The
proportion of APOEε4 carriers was elevated in amnestic but not aphasic
manifestations of AD. These results suggest that APOEε4 is an anatomically
selective risk factor that preferentially increases the vulnerability to
AD pathology of memory-related medial temporal areas rather that
language-related neocortices.