What Is Whole Genome Sequencing and How Is It Different from 23andMe?

Consumer DNA tests and clinical whole genome sequencing are completely different. Learn what WGS does, why it matters, and when you need it.

What Consumer DNA Tests Actually Do

Services like 23andMe use genotyping. They check roughly 600,000 to 700,000 specific positions in your genome. Your genome contains over 3 billion base pairs. Genotyping checks about 0.02% of your DNA.

These tests are designed for ancestry composition, traits, and carrier status for a small number of well-studied conditions. They cannot identify rare mutations, novel variants, structural changes, or the vast majority of gene disruptions that cause rare diseases.

What Whole Genome Sequencing Does

WGS reads your entire DNA sequence. All 3 billion base pairs. Every gene. Every regulatory region. It can identify single nucleotide variants, insertions and deletions, structural variants, copy number variants, and mitochondrial DNA variants.

Clinical WGS is performed in a CLIA-certified lab and interpreted by board-certified geneticists who evaluate your variants against databases of known disease-causing mutations and current medical literature.

The Numbers

Consumer genotyping checks roughly 600,000 positions. Clinical WGS reads over 3,000,000,000.

Consumer tests screen for variants in maybe 40-50 conditions. Clinical WGS covers all 20,000+ known genes.

Consumer tests are not diagnostic medical tests. Clinical WGS is a medical-grade diagnostic tool.

A negative result on a consumer test tells you almost nothing about whether you have a rare genetic disease. The test simply wasn't looking for it.

This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before making medical decisions.