DNA Test Comparison: Accuracy, Cost, and Which Test is Best

Consumer DNA testing has exploded since 2006, with millions exploring genetics through 23andMe, AncestryDNA, MyHeritage, and Nebula Genomics. Different tests use different technologies and provide vastly different information—from ancestry to health predispositions to detailed genetic variants.

This guide compares major DNA test companies and helps you choose the right test based on your goals: ancestry research, health insights, or comprehensive genomic data for personalized medicine.

DNA Testing Technologies: Genotyping vs Whole Genome Sequencing

The fundamental distinction is genotyping versus whole genome sequencing (WGS). This determines what information you receive.

Genotyping analyzes 600,000-1 million specific locations called SNPs using microarray chips. Companies like 23andMe, AncestryDNA, and MyHeritage use this method for $99-$199. It reads only 0.02% of your genome but captures commonly studied variations relevant to ancestry and health. Accuracy is >99% for tested SNPs, though it cannot detect variants outside pre-selected positions.

Whole genome sequencing reads all 3 billion base pairs. Nebula Genomics offers 30x WGS for $249-$299, reading each position 30 times for accuracy. This enables rare variant detection, copy number analysis, and mitochondrial DNA examination. However, many identified variants remain poorly understood by science.

Practical difference: genotyping suffices for ancestry and common markers like MTHFR C677T, APOE4, or COMT variants. WGS is necessary for comprehensive pharmacogenomics and rare disease assessment. Most people start with genotyping and upgrade to WGS if needing comprehensive data.

Comparing Major DNA Test Companies: Features and Accuracy

23andMe ($99-$229) offers the most comprehensive health reporting with FDA authorization for genetic health risks including BRCA1/BRCA2 (three Ashkenazi variants), APOE4 for Alzheimer's risk, and carrier status for cystic fibrosis. Ancestry Service analyzes 1500+ regions. Health + Ancestry adds 10+ genetic health risks, 40+ carrier conditions, caffeine metabolism, and pharmacogenetics. Ancestry accuracy is 95-99%, strongest for European backgrounds.

AncestryDNA ($99) focuses on genealogy with 2600+ regions analyzed and the world's largest DNA database (20+ million users). Their algorithm excels at finding relatives and building family trees. Health information is minimal—only basic wellness traits. Ancestry accuracy is 95-99%, particularly strong for European and East Asian populations. Best for family tree research.

MyHeritage DNA ($79-$99) analyzes 2100+ regions with strong European coverage, especially Eastern European and Jewish heritage. Their 5+ million user database supports relative matching. Health reports are a $150 add-on. Platform strength is genealogy tools integrating DNA with historical records. Accuracy is 95-98% for ancestry.

Nebula Genomics ($249-$299) provides 30x WGS with weekly updates as research publishes. You receive complete genomic data and can query specific genes through their browser. Includes ancestry analysis, health risks, and exploration of any gene. Accuracy is >99.9% at 30x coverage. Best for maximum genetic information.

DNA Test Accuracy: What Different Tests Can and Cannot Tell You

All major tests are highly accurate for what they measure—limitations matter most. Genotyping achieves >99% accuracy for 600k-1M SNPs but misses rare variants and structural variations. If you have a rare BRCA mutation outside 23andMe's three tested variants, the test misses it.

Ancestry accuracy varies by population. European ancestry is 95-99% accurate due to extensive reference samples. African ancestry is 85-95% due to greater genetic diversity. Native American ancestry is often overestimated below 5% because algorithms confuse it with East Asian ancestry. Oceanian and Central Asian estimates are least accurate (80-90%).

Health predictions are accurate for common variants like APOE4 and MTHFR C677T but miss rare variants. 23andMe's BRCA report tests only 3 variants—missing hundreds of other BRCA mutations. Negative results don't rule out conditions; they mean you lack specific tested variants.

WGS provides near-complete accuracy but interpretation is challenging. You might have 50-100 variants of uncertain significance (VUS) with unclear clinical meaning for years. This is both strength (future-proof) and limitation (restricted immediate actionability).

Understanding your specific variants and their health implications requires personalized analysis. Chat about your genetic variants with Ask My DNA lets you ask "which CYP2D6 variants affect my medication metabolism" or "how does my COMT genotype influence stress response"—connecting raw data to actionable insights.

Choosing the Right DNA Test for Your Goals

For ancestry and genealogy, AncestryDNA offers the largest database (20M+ users) and most detailed regional breakdown (2600+ regions), ideal for finding relatives. 23andMe includes chromosome painting showing DNA segment origins. MyHeritage excels for Eastern European and Jewish ancestry.

For health information, 23andMe provides comprehensive FDA-authorized reports including BRCA, APOE4, and pharmacogenetics. Their $229 Health + Ancestry covers genetic health risks, carrier status, and medication response. These are screening tools, not diagnostic tests.

For comprehensive medical data, Nebula Genomics WGS ($249-$299) provides complete genomic information for pharmacogenomics, rare variants, and ongoing monitoring. Best for complex health issues or personalized medicine applications.

For budget-conscious users, start with genotyping ($79-$99) and download raw data. Upload files to third-party platforms like Ask My DNA, Promethease, or Genetic Genie for additional analysis beyond company reports.

For privacy, note 23andMe and Ancestry have received law enforcement requests. Nebula Genomics offers blockchain-based control. Use pseudonyms when ordering and avoid relative databases. Data deletion is available but relative matches remain visible to others.

FAQ

Is 23andMe more accurate than AncestryDNA?

Both have similar technical accuracy (>99% for tested SNPs, 95-99% for ancestry) but analyze different SNPs using different algorithms, creating 5-10% variation in ancestry percentages. AncestryDNA provides more detailed regional breakdowns (2600+ vs 1500+), while 23andMe offers chromosome painting and comprehensive health reports. Neither is universally "more accurate."

Can DNA tests detect all genetic diseases?

No. Consumer tests screen common variants in limited conditions. They miss rare mutations, don't sequence most genes completely, and don't detect chromosomal abnormalities or large deletions. Clinical genetic testing ordered by physicians uses medical-grade sequencing with diagnostic-quality results and genetic counseling. Consumer tests are screening tools that cannot rule out genetic conditions.

How often should I retest my DNA?

Never retest with the same technology—your DNA doesn't change. However, upgrading from genotyping to WGS provides more comprehensive data. Raw genotyping data can be reanalyzed as research advances without retesting. Companies update ancestry algorithms periodically, changing percentages slightly, but this reflects improved analysis algorithms, not DNA changes.

What should I do with my raw DNA data file?

Download immediately and store securely—companies may close or change policies. Upload to third-party platforms for additional health, ancestry, and trait insights. Platforms like Ask My DNA enable querying specific genes for personalized interpretations. Keep files backed up—they're permanent genetic records becoming more valuable as research progresses.

📋 Educational Content Disclaimer

This article provides educational information about DNA testing options and is not intended as medical advice. Always consult qualified healthcare providers for personalized medical guidance. Genetic information should be interpreted alongside medical history and professional assessment.