Clinical Genetic Testing vs. 23andMe: What’s the Difference?

If you are considering genetic testing for hereditary cancer risk, you may be weighing whether a consumer DNA test from a company like 23andMe is sufficient, or whether you need clinical-grade testing. The two may look similar on the surface, but the differences are medically significant.

What Consumer DNA Tests Actually Test

23andMe reports on 44 specific variants in the BRCA1 and BRCA2 genes, plus a small number of MUTYH variants. There are more than 3,500 known pathogenic variants in BRCA1 and BRCA2 alone. Testing for 44 of them means more than 98 percent of disease-causing BRCA variants are not covered by the consumer test. Learn about what genetic testing is and how it works.

What Clinical-Grade Testing Does Differently

• Full gene sequencing. Clinical testing reads the complete sequence of each gene, detecting known, rare, and novel variants.
• Multi-gene panels. Typically 40 to 80+ genes including BRCA, Lynch syndrome, PALB2, ATM, CHEK2, and many others.
• Sanger confirmation. Pathogenic findings are confirmed using a second, independent method.
• Certified laboratories. CLIA certification and CAP accreditation ensure quality, accuracy, and reproducibility.

The Counseling Gap

With clinical testing, your results are reviewed by a licensed genetic counselor who interprets them in the context of your complete history. Consumer tests deliver results through an online report with no individualized professional interpretation. The FDA requires 23andMe to include a disclaimer stating that its reports should not be used to make treatment decisions. Learn about the clinical testing process.

When Consumer Testing Falls Short

The risk of consumer testing is not that it gives wrong answers for the variants it tests — accuracy exceeds 99 percent. The risk is that it gives incomplete answers that create a false sense of security. A person with a strong family history who receives a negative 23andMe BRCA report may believe they are not at hereditary risk, but their family’s cancer could be driven by a variant not among the 44 tested.

The Bottom Line

When the question is whether you carry a hereditary cancer variant that could affect your health and your family’s health, the answer requires clinical-grade testing. If you have already taken a consumer test and your results were negative, that does not mean clinical testing is unnecessary. A clinical risk assessment can help determine whether comprehensive testing is warranted. Learn about who should consider clinical genetic testing.