Overview
APOE encodes Apolipoprotein E, a protein that plays a major role in lipid metabolism and is associated with Alzheimer’s risk.
19q13.32 (Chromosome 19)
Metabolism
Codominant
APOE-ε4: ~15% carry at least one allele
Function & Significance
Apolipoprotein E is a major component of lipoproteins and plays a central role in the transport and metabolism of cholesterol and other lipids in the body.
🧬 APOE Variants
There are three main variants of the APOE gene:
- APOE-ε2 – Potentially protective against Alzheimer’s
- APOE-ε3 – Most common variant, neutral
- APOE-ε4 – Significantly increases Alzheimer’s risk
Associated Diseases
-
🧠 Alzheimer’s Disease
APOE-ε4 is the strongest genetic risk factor for sporadic Alzheimer’s disease
-
❤️ Cardiovascular Diseases
Influence on cholesterol levels and atherosclerosis risk
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💉 Hyperlipoproteinemia Type III
Rare lipid metabolism disorder
Clinical Relevance
⚕️ APOE Genotyping
APOE testing can be helpful for:
- Risk assessment for Alzheimer’s disease
- Evaluation of cardiovascular risk
- Personalized prevention strategies
Important: APOE-ε4 does not mean you will definitely develop Alzheimer’s – it only increases the risk.
💊 Prevention & Management
Recommended for APOE-ε4 carriers:
- Healthy nutrition (Mediterranean diet)
- Regular physical activity
- Mental stimulation
- Monitoring of cholesterol and blood pressure
- Avoidance of head injuries
🧬 Relevant SNPs (Single Nucleotide Polymorphisms)
The APOE variants are defined by two SNPs:
19:44908684
/
Significance: Defines the APOE ε4 allele (increased Alzheimer’s risk). The C allele is associated with a 3-4 fold increased risk for Alzheimer’s disease.
19:44908822
/
Significance: Defines the APOE ε2 allele (possibly protective). The T allele may be linked to a reduced Alzheimer’s risk.
📊 APOE Genotypes
The combination of these two SNPs determines the APOE genotype:
- ε2/ε2, ε2/ε3: Potentially protective
- ε3/ε3: Neutral (most common genotype)
- ε3/ε4: Moderately increased risk
- ε4/ε4: Significantly increased risk (10-15 fold)
📚 Data Sources
The information on this page is based on the following scientific sources:
- OMIM: #107741 – Online Mendelian Inheritance in Man
- AlzGene Database: Alzheimer Disease Genetics
- dbSNP: rs429358, rs7412 – SNP Database (NCBI)
- ClinVar: Clinical Variant Database (NCBI)
- PubMed: Cardiovascular & Alzheimer Research
Last Update: February 2026
Biological Function
Associated Conditions
Analyzed Markers
Defines APOE ε4 allele (increased Alzheimer's risk)
Defines APOE ε2 allele (possibly protective)