Genetic & Epigenetic Testing
From APOE genotyping and BRCA screening to polygenic risk scores and DNA methylation analysis — what genetic tests reveal about your predispositions and how fast you are aging.
Key Takeaways
- →APOE genotyping identifies carriers of the ε4 allele, the strongest common genetic risk factor for Alzheimer's disease.
- →Polygenic risk scores aggregate thousands of small genetic effects to estimate disease probability — but they are not destiny.
- →Pharmacogenomic testing can guide medication selection and dosing for statins, blood thinners, antidepressants, and more.
- →Epigenetic (DNA methylation) testing measures biological aging and is responsive to lifestyle changes.
Genetic testing provides a unique form of health information: it reveals inherited predispositions that do not change over your lifetime. While your genes are not your destiny — lifestyle, environment, and epigenetics all modulate gene expression — knowing your genetic risk profile allows for targeted screening, earlier intervention, and personalized prevention strategies.
Single-Gene Risk Variants
- •APOE genotype — The APOE gene has three common variants: ε2, ε3, and ε4. Carrying one copy of ε4 increases Alzheimer's risk roughly 3-fold; two copies increase it 8–12-fold (Lancet Neurology, 2013). APOE4 also affects cholesterol metabolism and cardiovascular risk. Knowing your status can inform screening frequency and lifestyle optimization.
- •BRCA1 / BRCA2 — Pathogenic variants in these tumor suppressor genes dramatically increase lifetime risk of breast cancer (45–72%) and ovarian cancer (10–44%). The National Comprehensive Cancer Network (NCCN) recommends genetic counseling and testing for individuals with significant family history.
- •MTHFR variants — C677T and A1298C polymorphisms affect folate metabolism and can elevate homocysteine. Clinical significance is debated, but carriers may benefit from methylated folate (L-methylfolate) rather than synthetic folic acid.
- •Factor V Leiden / Prothrombin G20210A — Clotting factor mutations that increase deep vein thrombosis and pulmonary embolism risk. Important before hormone therapy or oral contraceptives.
Polygenic Risk Scores (PRS)
Most common diseases are not caused by a single gene but by the cumulative effect of thousands of small-effect variants. Polygenic risk scores aggregate these variants into a single number that estimates relative disease risk. PRS are commercially available for coronary artery disease, type 2 diabetes, breast cancer, prostate cancer, and several other conditions.
PRS limitations
Polygenic risk scores are primarily validated in populations of European ancestry and may be less accurate for other ethnic groups. They estimate relative risk, not absolute risk, and should be interpreted alongside clinical risk factors — not in isolation. A high PRS does not guarantee disease, and a low PRS does not guarantee protection.
Pharmacogenomics
Pharmacogenomic testing analyzes gene variants that affect how your body metabolizes medications. The Clinical Pharmacogenetics Implementation Consortium (CPIC) has published guidelines for over 400 drug-gene pairs. Practically, this can guide dosing for statins (SLCO1B1 gene — risk of myopathy with simvastatin), blood thinners (CYP2C19 — clopidogrel activation), antidepressants, proton pump inhibitors, and pain medications.
Epigenetic Testing (DNA Methylation)
While genetic sequence does not change, DNA methylation — the pattern of chemical marks on your DNA — changes with age, lifestyle, and environment. Epigenetic clocks use methylation patterns to estimate biological age. Unlike genetic tests, epigenetic tests can be repeated over time to track the effect of interventions. TruDiagnostic's TruAge test is currently the most comprehensive consumer option, reporting GrimAge, DunedinPACE, and other clock outputs.
Genetic testing is a one-time investment
Since your DNA sequence does not change, most genetic tests only need to be performed once. Epigenetic tests, however, measure dynamic marks and should be repeated every 6–12 months to track trends. Budget accordingly when building your testing stack.