Genetics

Genetic Testing: Complete Guide

Genetic testing has expanded rapidly, from medical diagnostic tests to consumer ancestry/health kits. Understanding the differences helps you interpret results appropriately.

Medical genetic testing
Requires genetic counselling, clinical indication
Consumer tests
Variable quality, limited clinical validity for many claims
BRCA testing
For hereditary breast/ovarian cancer risk
Key point
Results need professional interpretation

Medical vs Direct-to-Consumer Testing

FeatureMedical Genetic TestingDirect-to-Consumer (DTC)
Ordered byClinical geneticist/specialist based on family history/symptomsPurchased directly by consumer online
CounsellingPre- and post-test genetic counselling standardUsually minimal or absent
Clinical validityHigh for tested conditionsVariable — ancestry generally reliable; health predictions often limited
ActionabilityResults guide specific medical decisionsOften limited direct clinical action recommended

BRCA Testing — A Key Example

BRCA1/2 gene testing is offered to people with significant family history of breast/ovarian cancer (multiple affected relatives, early-onset cases, certain ethnic backgrounds with higher prevalence). Positive results significantly inform risk-reducing strategies (enhanced screening, preventive surgery, medication) but require genetic counselling before and after testing given the profound implications.

Limitations of Consumer Genetic Health Tests

Seek Genetic Counselling for Significant Family HistoryIf you have a strong family history of cancer, heart disease, or other conditions with known genetic components, ask your doctor about referral to genetic counselling services rather than relying solely on consumer testing — this ensures appropriate testing and support for interpreting results.
Should I get a consumer genetic health test?
These can be interesting for ancestry and some limited health insights, but shouldn't replace proper medical genetic testing when there's a clinical indication (strong family history), and results should be discussed with a healthcare professional rather than acted upon independently.
What happens if I test positive for BRCA1/2?
This significantly increases lifetime breast and ovarian cancer risk, and options include enhanced screening (earlier, more frequent mammograms/MRI), risk-reducing medication, or preventive surgery — decisions are highly personal and made with specialist genetic counselling support.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.