What Genetic Testing Can Tell You
Genetic testing has transformed how we understand personal health. At its most powerful, it can identify specific mutations that significantly raise disease risk — such as BRCA1 and BRCA2 variants linked to breast and ovarian cancer, or APOE variants associated with Alzheimer's disease. These are high-impact findings that can directly inform medical decisions.
Beyond single-gene mutations, polygenic risk scores (PRS) assess hundreds or thousands of small genetic variants across your genome to estimate your likelihood of developing conditions like type 2 diabetes, heart disease, or certain cancers. Think of it like a weather forecast: it tells you the probability, not the certainty.
What Genetic Testing Cannot Predict
Here's where many people are surprised. Having a genetic variant does not mean you will develop a condition. Most health outcomes are influenced by a combination of genes, environment, lifestyle, and chance. A 'high-risk' score for heart disease does not guarantee a heart attack — and a 'low-risk' score is not a green light to ignore your health.
Consumer genetic tests also vary widely in what they cover. Many test only a small subset of known variants, meaning a negative result can create false reassurance.
Genes vs Environment, Explained Simply
A useful way to think about it: your genes set the stage, but your daily choices influence the performance. Epigenetics — the science of how lifestyle and environment affect how your genes behave — shows us that factors like diet, exercise, stress, and sleep can literally switch genes on or off over time.
You are not defined by your DNA. But understanding it can give you a significant head start.
When Genetic Results Are Actionable
Some findings are immediately clinically relevant:
- A BRCA variant may prompt consideration of enhanced screening or preventive surgery
- A hereditary cholesterol condition may change medication decisions
- Carrier status results may be important for family planning
Other findings — particularly polygenic risk scores — are best used as motivation to adopt protective lifestyle habits, not as diagnoses.
When to Seek Guidance from a Genetic Counsellor
Genetic results can feel overwhelming, especially when they touch on serious conditions or carry implications for family members. A genetic counsellor is trained to help you understand what your results actually mean for your specific situation, put probabilities into context, and guide next steps without unnecessary alarm.
If you're unsure what your results mean, a Jeen genetic counsellor can walk you through it — clearly, calmly, and at your own pace.
