Cardio IQ APOE Genotype
The Cardio IQ APOE Genotype test identifies which ε2, ε3, or ε4 alleles an individual carries, informing cardiovascular risk, lipid metabolism, dietary response, and Alzheimer susceptibility. The ε4 allele raises LDL cholesterol and Alzheimer risk in a dose-dependent manner, while ε2 lowers LDL but predisposes to type III dyslipidaemia;
1
Biomarkers
Blood (whole blood)
Sample
7–10 business days
Turnaround
No
Fasting
What is the APOE Genotype test?
The Cardio IQ APOE Genotype test identifies which combination of the three major APOE alleles—ε2, ε3, and ε4—an individual carries, providing genetic insight into lipid metabolism, cardiovascular risk, and susceptibility to Alzheimer disease. Although routine lipid screening does not require genotyping, practitioners order APOE when personalised risk assessment, refractory dyslipidaemia, or family history prompts consideration of genetic modifiers. APOE genotype is particularly useful in patients with discordant lipid profiles or suboptimal responses to standard therapy, in those with type III dyslipidaemia (dysbetalipoproteinaemia), and when evaluating individuals with a strong family history of premature cardiovascular disease or dementia. In the functional and preventive medicine context, the result guides dietary counselling—ε4 carriers may benefit from stricter saturated-fat limits—and informs discussions around cognitive health, though it must be framed as a risk modifier rather than a deterministic test.
What does the APOE Genotype test measure?
Apolipoprotein E is a plasma glycoprotein synthesised predominantly in the liver and brain that mediates uptake of lipoproteins by binding to hepatic receptors, playing a central role in cholesterol transport and metabolism. The APOE gene on chromosome 19 has three major alleles—ε2, ε3, and ε4—that differ by single amino-acid substitutions at positions 112 and 158, altering receptor binding affinity and lipoprotein clearance. The ε3 allele is the ancestral and most prevalent form; ε2 binds poorly to receptors and is associated with lower LDL cholesterol and modestly higher triglycerides, while ε4 increases receptor binding and LDL cholesterol and is the strongest common genetic risk factor for late-onset Alzheimer disease.
APOE genotype influences both cardiovascular and neurological disease risk. In lipid metabolism, ε4 carriers typically have higher baseline LDL cholesterol and may show a more robust LDL response to dietary saturated fat and statin therapy, while ε2 carriers have a lower LDL but are predisposed to type III dyslipidaemia when combined with secondary factors. In neurology, the ε4 allele is associated with a dose-dependent increase in Alzheimer risk and earlier disease onset, although it is neither necessary nor sufficient for diagnosis. Genotyping informs stratification of cardiovascular risk, guides lipid-lowering strategy, and—when appropriately counselled—can contribute to discussions of cognitive health and preventive planning.
Why is the APOE Genotype test ordered?
- Patients with refractory or atypical dyslipidaemia, particularly when type III dyslipidaemia (broad-β disease) is suspected on the basis of elevated cholesterol and triglycerides and palmar xanthomas
- Individuals with a strong family history of premature atherosclerotic cardiovascular disease or hyperlipidaemia, to refine heritable risk
- Patients seeking personalised dietary and lipid-management strategies, especially those interested in gene-informed nutrition and saturated-fat response
- Adults with a family history of early-onset Alzheimer disease or multiple affected relatives, when appropriately counselled regarding the probabilistic nature of ε4 risk
- Patients undergoing comprehensive cardiometabolic or longevity-focused assessment panels where genetic lipid modifiers add clinical value
- Evaluation of unexpected statin hyper-response or side effects, where APOE genotype may contextualise individual variability
- Risk stratification in asymptomatic individuals with borderline lipid abnormalities, when genotype will influence intensity of intervention
Sample collection and turnaround
Sample type
Blood (whole blood)
Fasting required
No
Collection method
Venipuncture at patient service centre
Turnaround
7–10 business days
Collection notes
Phlebotomy via Quest; whole blood collected into EDTA (lavender-top) tube for genomic DNA extraction. No special preparation required. Genotype is a one-time test unless there is concern about sample integrity or labeling error.
Specimen requirements
Minimum 3 mL whole blood in EDTA. DNA is stable at room temperature for several days and refrigerated or frozen for long-term storage. Avoid haemolysis and ensure correct patient identification to prevent sample mix-up.
What can affect APOE Genotype results?
APOE genotyping is performed on genomic DNA, so specimen integrity and correct labeling are critical; contamination or sample mix-up will yield incorrect genotype.
Hypothyroidism, diabetes, nephrotic syndrome, and alcohol excess can alter lipid phenotype independent of APOE; genotype interpretation requires exclusion of secondary factors.
Statins, fibrates, and other drugs alter circulating lipids but not the genotype; therapy does not interfere with the test itself but may mask the baseline lipid phenotype associated with a given APOE variant.
ε4 frequency varies by ancestry (higher in northern Europeans, lower in some Asian and African populations), which influences pre-test probability but not assay validity; risk estimates derived from European cohorts may not extrapolate precisely.
The assay detects the common ε2, ε3, and ε4 alleles; extremely rare variants may not be identified, though they account for a negligible fraction of cases.
What do APOE Genotype results mean?
Elevated
Not applicable — APOE genotyping reports allelic combinations (e.g., ε3/ε4, ε4/ε4) rather than quantitative elevation. ε4/ε4 homozygosity confers the highest cardiovascular and Alzheimer risk; one ε4 copy is intermediate. ε2/ε2 or ε2/ε3 with hypertriglyceridaemia suggests type III dyslipidaemia.
Normal
ε3/ε3 is the most common genotype and serves as the population reference, associated with average lipid metabolism and Alzheimer risk. A 'normal' genotype does not eliminate cardiovascular or cognitive risk, which depend on the totality of genetic, environmental, and lifestyle factors.
Reduced
Not applicable — the test reports genotype, not a level. ε2 homozygosity is associated with lower LDL cholesterol under normal conditions but predisposes to type III dyslipidaemia in the presence of metabolic stress or secondary factors.
Note: APOE genotype is one piece of a multifactorial risk profile and should never be used in isolation to diagnose disease or make treatment decisions. An ε4 allele increases Alzheimer risk but is not deterministic — many ε4 carriers do not develop dementia, and many patients with Alzheimer lack ε4. Informed consent and genetic counselling are essential before ordering, particularly when cognitive risk is the primary concern. Results are lifelong and may have implications for family members; consider privacy, psychological impact, and potential consequences for insurance or employment where genetic-discrimination protections vary.
Frequently asked questions
The three common alleles are ε2, ε3, and ε4, differing by single amino-acid substitutions that alter receptor binding. ε3 is the most common and serves as the reference; ε4 increases LDL cholesterol and Alzheimer risk, while ε2 lowers LDL but can cause type III dyslipidaemia in certain contexts.
How to access the APOE Genotype test
The APOE Genotype reference page is free and open to all practitioners. Create a free practitioner account to see pricing, save tests to your list, and generate requisition forms. Verification takes 1–2 business days.
Create Free AccountAbout this page
Published: October 7, 2026
Last reviewed: October 7, 2026
- Mahley RW. Apolipoprotein E: from cardiovascular disease to neurodegenerative disorders. J Mol Med. (2016)
- Grundy SM, et al. 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA guideline on the management of blood cholesterol. (2019)
- Farrer LA, et al. Effects of age, sex, and ethnicity on the association between apolipoprotein E genotype and Alzheimer disease: a meta-analysis. JAMA. (1997)
- National Institute on Aging and Alzheimer's Association workgroup on genetic testing for Alzheimer disease. Consensus recommendations. (2013)
- Eichner JE, et al. Apolipoprotein E polymorphism and cardiovascular disease: a HuGE review. Am J Epidemiol. (2002)
This content is for licensed healthcare practitioners only and does not constitute medical advice. Clinical decisions should be based on the full clinical picture and not on any single test result.
Related tests
cardiovascular
Apo-B
The Apolipoprotein B (Apo-B) test counts the total number of atherogenic lipoprotein particles, since each LDL, VLDL, IDL, and lipoprotein(a) particle carries one apolipoprotein B. It is a strong cardiovascular risk marker, in many analyses superior to LDL cholesterol because it captures particle number rather than cholesterol content, and is especially informative where LDL cholesterol…
cardiovascular
LDL Cholesterol
The LDL Cholesterol test measures the concentration of cholesterol carried within low-density lipoprotein particles in serum, serving as the cornerstone lipid parameter for cardiovascular risk assessment, lipid-lowering therapy initiation, and treatment-to-target monitoring.
cardiovascular
Lp(a)
The lipoprotein(a) [Lp(a)] test measures a genetically determined, LDL-like particle that is an independent risk factor for atherosclerotic cardiovascular disease and aortic valve stenosis. Because its level is largely inherited and stable through life, a single measurement usually suffices to establish lifelong risk.