I've spent years working in genomics, and the most common question I get isn't about the science. It's from someone who's done a consumer genetic test and wants to know: "Should I be worried about this result?" The answer is almost always more nuanced than the report makes it look.
What You Need to Know
- Consumer genetic tests provide probabilistic risk information, not diagnoses - a "higher risk" result doesn't mean you'll develop a condition
- Polygenic risk scores aggregate hundreds of genetic variants into a single risk estimate, but environmental factors, lifestyle, and family history matter as much or more for most conditions
- Pharmacogenomic results (how you respond to medications) are among the most clinically actionable outputs of consumer genetics
- Genetic results should be interpreted with a health professional - direct-to-consumer reports lack the clinical context to be fully meaningful
What the Test Actually Does
When you take a consumer genetic test, a lab analyses specific locations in your DNA. Depending on the test, this could be a few hundred locations (basic ancestry and trait tests) or several hundred thousand (comprehensive health-focused panels).
The lab compares your genetic variants to population databases. If your variant at a particular location matches one associated with, say, increased risk of type 2 diabetes in research studies, the report flags it.
700K+
genetic variants typically analysed in a comprehensive consumer health genetic test, out of roughly 4-5 million common variants in the human genome
Source: National Human Genome Research Institute, 2023
This sounds comprehensive. It's important to understand what it is and isn't.
What It Is
A snapshot of your genetic predispositions. Your DNA doesn't change. The test gives you a permanent dataset about your inherited risk factors, drug metabolism profiles, carrier status for certain conditions, and trait predispositions.
Probabilistic, not deterministic. A genetic result tells you about likelihood, not certainty. Having a genetic variant associated with higher cardiovascular risk means you're statistically more likely to develop cardiovascular disease than someone without that variant, all else being equal. All else is never equal.
One input among many. Your genetics are one layer of your health picture. Environment, lifestyle, diet, stress, sleep, social connection, and access to healthcare all modify how your genetic predispositions play out.
What It Isn't
A diagnosis. A higher genetic risk for a condition is not the same as having that condition. I've seen people receive a genetic report and assume they're destined for a disease. That misunderstanding causes real harm.
Complete. Consumer tests analyse common variants. Rare variants, structural changes, and complex gene interactions are typically not covered. A "clear" consumer genetic report doesn't mean you have no genetic risk factors - it means the ones tested weren't flagged.
Static in interpretation. The science of genomics moves fast. A variant classified as "uncertain significance" today might be reclassified next year as new research emerges. Your DNA doesn't change, but our understanding of it does.
The Categories That Matter
Not all genetic results are equally useful. Here's how I think about the different categories.
Pharmacogenomics - The Most Actionable
This is the category I find most immediately valuable. Pharmacogenomic testing tells you how your body metabolises specific medications. Are you a rapid metaboliser of a common antidepressant? A poor metaboliser of a standard pain medication? This information directly changes what a clinician prescribes.
99%
of people carry at least one actionable pharmacogenomic variant that could affect their response to a commonly prescribed medication
Source: Clinical Pharmacogenetics Implementation Consortium (CPIC), 2021
When I was at Edison, pharmacogenomics was one of our strongest use cases. A patient going on a new medication could have their pharmacogenomic profile checked first, potentially avoiding weeks of trial and error with drugs that wouldn't work for them.
This is precision health at its most practical. Remove the guesswork from prescribing.
Polygenic Risk Scores - Useful With Context
Polygenic risk scores combine the effects of hundreds or thousands of genetic variants into a single risk estimate for conditions like heart disease, type 2 diabetes, or certain cancers.
These scores are genuinely informative at a population level. A person in the top 5% of polygenic risk for coronary artery disease has a meaningfully elevated risk compared to the median. That's useful clinical information.
The challenge is interpretation. A high polygenic risk score for a condition doesn't mean you'll develop it. A low score doesn't mean you won't. Environmental and lifestyle factors interact with genetic risk in ways we're still mapping. The score is one input for a clinical conversation, not a verdict.
Genetic testing doesn't tell you your future. It tells you your predispositions. What you do with that information - with the guidance of a clinician - is what actually shapes your health outcomes.
Jay Harrison
Health Technology Advisory
Carrier Status - Important for Family Planning
Carrier screening identifies whether you carry variants for recessive genetic conditions. You might be perfectly healthy but carry a variant that, if your partner carries the same one, could result in an affected child.
This information is most valuable before or during family planning. It's straightforward to test for, well understood scientifically, and has clear clinical pathways.
Ancestry and Traits - Interesting, Not Clinical
Eye colour prediction, earwax type, caffeine sensitivity - these are the genetic results that make dinner party conversation. They're scientifically valid but clinically irrelevant. Enjoy them for what they are.
How to Use Your Results
If you've taken or are considering a consumer genetic test, here's my practical guidance.
Don't interpret alone. Take your results to a GP or genetic counsellor. The report gives you data. A clinician gives you context. The combination is what matters.
Focus on actionable categories. Pharmacogenomic results and high-risk polygenic scores are worth discussing with your doctor. Ancestry results are for your own interest.
Understand the limitations. A consumer test is not a clinical-grade diagnostic. If a result concerns you, a clinician can order targeted clinical testing that's more comprehensive and more precise.
Revisit periodically. As genomic science advances, the interpretation of your variants may change. Some testing companies update reports as new research emerges. Check back annually.
Share with your health team. If you have actionable results, make sure they're in your clinical record. A pharmacogenomic profile is only useful if your prescribing doctor knows about it.
Don't panic. Elevated genetic risk is not a sentence. It's information. Information that, combined with lifestyle choices and clinical monitoring, can help you make better health decisions.
- Are consumer genetic tests accurate?
- The genotyping itself is highly accurate - typically over 99% for the variants tested. The interpretation of what those variants mean for your health is where uncertainty enters. The science is evolving, and population databases used for comparison have historical biases toward European-descent populations.
- Should everyone get genetic testing?
- I believe genetic information is valuable for everyone, but it needs to come with clinical interpretation. A test without guidance can cause unnecessary anxiety or false reassurance. If you're considering it, plan to discuss results with a health professional.
- Can an employer or insurer access my genetic results?
- In New Zealand, genetic information is protected under the Privacy Act and the Human Rights Act prohibits discrimination based on genetic status. Your results are your personal health information. However, be aware of the terms of service for any consumer testing company - read how they handle and store your data.