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Probable early-onset Alzheimer's disease in an apolipoprotein E2 homozygote
Lauren Cole1, Christine Belden, Sandra Jacobson
1Cleo Roberts Center for Clinical Research, Banner Sun Health Research Institute, Sun City, AZ 85351, USA.
Objective:
To describe a case of early-onset Alzheimer's disease (AD) in an apolipoprotein (Apo) ε2/ε2 homozygote.
Background:
Apo ε2/ε2 is the rarest of the ApoE genotypes, representing only 1.4% of the population. Cognitive decline in ApoE ε2 homozygotes has rarely been reported.
Case Report/Methods:
We report a 58-year-old Apo ε2/ε2 female who meets clinical criteria for probable AD as confirmed by neuropsychological testing, positron emission/computed tomography scan, CSF analysis and genetic screening for known mutations.
Results:
The clinical course is typical of AD, with progressive cognitive and functional decline.
Conclusion:
Clinically confirmed early-onset AD is atypical in ApoE2 homozygotes but can occur.
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