Genetic testing has moved from research labs to consumer apps. For £100, you can get a report on everything from ancestry to disease risk. But the gap between what consumer genetic testing provides and what clinical genetic testing delivers is enormous — and misunderstanding the difference can lead to either false reassurance or unnecessary panic.
Consumer vs clinical genetic testing
Consumer tests (23andMe, AncestryDNA) look at selected genetic variants — single nucleotide polymorphisms (SNPs). They provide probability estimates for certain conditions. A "higher risk" result doesn't mean you'll develop the condition. A "normal risk" result doesn't mean you won't. These tests are informative for curiosity. They are not diagnostic.
Clinical genetic testing — ordered by a geneticist or specialist — analyses specific genes with clinical-grade accuracy. BRCA testing for breast cancer risk. Lynch syndrome testing for colorectal cancer. Pharmacogenomics testing to predict drug metabolism. These results directly change clinical management.
When clinical genetic testing is warranted
If you have a strong family history of cancer (particularly breast, ovarian, colorectal, or prostate), a referral to clinical genetics for risk assessment and potentially testing is appropriate. NHS criteria exist for who qualifies, but the thresholds can be pushed if your family history is concerning.
Pharmacogenomics — testing how your genes affect drug metabolism — is increasingly useful for psychiatric medications, cardiovascular drugs, and pain management. Knowing whether you're a rapid or slow metaboliser of certain drugs can explain why standard doses don't work for you.
The results conversation
Genetic results without proper counselling are dangerous. A BRCA1 positive result without context can be devastating. With proper genetic counselling, it becomes an actionable piece of intelligence that enables proactive risk management — enhanced screening, risk-reducing surgery if appropriate, and informed family planning.
If you're considering genetic testing, ensure you have access to a qualified genetic counsellor who can interpret the results and guide the clinical response. A raw data file is not a diagnosis.