Probable early-onset Alzheimer's disease in an apolipoprotein E2 homozygote.
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.


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.


CONCLUSIONS
Clinically confirmed early-onset AD is atypical in ApoE2 homozygotes but can occur.
Cleo Roberts Center for Clinical Research, Banner Sun Health Research Institute, Sun City, AZ 85351, USA.
Lauren
L
Cole
Christine
C
Belden
Sandra
S
Jacobson
Carolyn
C
Liebsack
Kent
K
Myers
Cornelia
C
Reninger
Camryn
C
Berk
Marwan N
MN
Sabbagh
D017668:Age of Onset; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000235:genetics*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid; D053329:Apolipoprotein E2 / Q000235:genetics*; D003071:Cognition / Q000502:physiology; D004252:DNA Mutational Analysis; D005260:Female; D006720:Homozygote; D006801:Humans; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed; D016875:tau Proteins / Q000134:cerebrospinal fluid
D016229:Amyloid beta-Peptides; D053329:Apolipoprotein E2; D016875:tau Proteins