APOE Genotype

Apolipoprotein E (APOE) genotype refers to the specific combination of APOE gene variants (alleles ε2, ε3, ε4) an individual inherits. This genotype significantly influences lipid metabolism and cardiovascular risk (e.g., ε4 increases LDL-C and ASCVD risk) and is the strongest genetic risk factor for late-onset Alzheimer's disease (especially the ε4 allele).

Important Considerations:

• This genetic test has implications for long-term health risks. Discuss the results and their meaning with a qualified healthcare provider or genetic counselor.
• APOE genotype is not deterministic. Having a risk allele (ε4) increases risk but does not guarantee disease development. Conversely, not having a risk allele does not eliminate risk.
• Overall risk for cardiovascular disease and Alzheimer's is influenced by many factors, including lifestyle (diet, exercise, sleep), environment, and other genetic factors.

Interpretation (Relative Alzheimer's Risk vs. ε3/ε3 - Most Common Genotype):

• ε2/ε2 or ε2/ε3: Reduced risk (~50% lower).
• ε3/ε3: Average risk (baseline).
• ε2/ε4 or ε3/ε4: Elevated risk (approx. 2-3 fold).
• ε4/ε4: Significantly elevated risk (approx. 10-15 fold).

(References: PMID: 34666174, PMC3726719, s41467-019-14279-8, s41467-020-18198-x)