Outline the genetic association of Apolipoprotein E with Alzheimer’s Disease (AD) and describe its function in the brain. What is the likelihood that the patient will develop early onset AD (before 60 years of age

Outline the genetic association of Apolipoprotein E with Alzheimer’s Disease (AD) and describe its function in the brain. What is the likelihood that the patient will develop early onset AD (before 60 years of age

what question

APOE and Alzheimer’s Disease

layout

component details

components

APOE Function
Alleles
Risk Association
Mechanism in AD
Early-Onset AD
Likelihood of Early-Onset
Testing Implication

APOE Function

Lipid transport, neuronal repair in CNS

Alleles

ε2 (protective), ε3 (neutral), ε4 (risk)

Risk Association

ε4/ε4 → 10–15× risk; ε3/ε4 → 2–3× risk

Mechanism in AD

Promotes amyloid-beta aggregation and reduced clearance

Early-Onset AD

Usually caused by mutations in APP, PSEN1, or PSEN2—not APOE

Likelihood of Early-Onset

Low, unless rare high-penetrance mutations are present

Testing Implication

APOE genotyping gives risk insight, not diagnos