Is whole genome sequencing better than genotyping?

It depends on your goals. WGS provides far more data — all 3 billion base pairs vs. ~700,000 SNPs — making it better for comprehensive health screening, rare disease diagnosis, pharmacogenetics, and future-proofing (your data can be re-analyzed as science advances). Genotyping is cheaper and sufficient for basic ancestry estimates, a handful of FDA-authorized health reports, and relative matching. For most people interested primarily in ancestry or a few health traits, genotyping provides better value. For those seeking deep health insights, comprehensive pharmacogenetics, or a lifetime genetic resource, WGS is the superior choice.

How much more DNA does WGS read compared to 23andMe?

23andMe's genotyping chip reads approximately 600,000–700,000 single nucleotide polymorphisms (SNPs) — roughly 0.02% of your genome. Whole genome sequencing at 30x depth reads all 3 billion base pairs, providing approximately 5,000 times more raw data points. This difference means WGS captures rare variants, structural rearrangements, and variants in non-coding regulatory regions that genotyping chips completely miss.

Does WGS provide better ancestry information than AncestryDNA?

WGS provides more detailed Y-chromosome and mitochondrial DNA haplogroup data than most genotyping tests, and can be analyzed with third-party tools for deeper ancestry insights. However, for basic ethnicity estimates and relative matching, the large databases of AncestryDNA (25+ million users) and 23andMe (14+ million users) provide more value through DNA matches. WGS providers have much smaller databases, so you will find far fewer genetic relatives. Many users combine both — a one-time WGS for health data and a genotyping test for ancestry matches.

Can I upload WGS data to third-party interpretation tools?

Yes, but with limitations. Most third-party tools like Promethease, Genetic Genie, and SelfDecode are designed for genotyping data files and only accept SNPs. WGS files (typically FASTQ, BAM, or VCF format) are far larger and require specialized tools. Some providers like Sequencing.com and SelfDecode accept WGS VCF files for analysis. Nebula Genomics includes its own interpretation platform with regular updates, reducing the need for third-party tools. Before purchasing WGS, confirm whether your preferred analysis tools accept whole genome data.

Is WGS a one-time purchase or do I need to re-test later?

WGS is a one-time purchase because your genome does not change. Once sequenced, your data file can be re-analyzed indefinitely as new genes are discovered and variant classifications are updated. This future-proofing is one of WGS's primary advantages over genotyping. Providers like Nebula Genomics offer subscription-based updates that periodically re-analyze your genome against the latest scientific databases. With genotyping, if a new important SNP is discovered after you purchase the chip, you would need to buy a newer version of the test to see it.

WGS vs Genotyping: Which DNA Test Is Right for You?

600,000 vs. 3,000,000,000

Consumer genotyping chips test approximately 600,000–700,000 positions in your DNA. Whole genome sequencing reads all 3 billion base pairs. That's the difference between scanning the chapter titles and reading the entire book. — Nature Reviews Genetics, 2023

Understanding the Two Technologies

Before comparing products, it is essential to understand what each technology actually measures. The differences are fundamental, not incremental — they represent two entirely different approaches to reading your genetic code.

How Genotyping Works

Genotyping chips are arrays of microscopic beads, each coated with short DNA probes designed to capture a specific genetic variant. When your DNA sample is washed over the chip, fragments that match a probe stick to it. A fluorescent signal indicates which variant you carry at that position.

The key limitation: genotyping chips only test positions that were pre-selected when the chip was designed. Companies like 23andMe and AncestryDNA use chips manufactured by Illumina that target 600,000–700,000 single nucleotide polymorphisms (SNPs). These SNPs were chosen because they are common in the population (present in >1% of people) and useful for ancestry inference or known disease associations. But they represent approximately 0.02% of your genome. The remaining 99.98% is invisible to the chip.

Furthermore, genotyping chips are designed once and used for years. If a new disease-associated variant is discovered after the chip design is finalized, the chip cannot detect it. Your data is frozen in time.

How Whole Genome Sequencing Works

WGS takes a fundamentally different approach. Instead of checking pre-selected positions, it reads the entire DNA sequence from end to end using sequencing by synthesis. Your DNA is fragmented, amplified, and each fragment is read by a high-speed camera as fluorescently labeled bases are added. The result is a digital file containing every position in your genome that the instrument could resolve.

Because WGS is non-targeted, it detects variants that were unknown when the technology was developed. Your WGS data file can be re-analyzed against new databases for years or decades after the original sequencing run. This future-proofing is one of WGS's most compelling advantages.

Head-to-Head Comparison

Feature	WGS (Nebula, Dante Labs)	Genotyping (23andMe, AncestryDNA)
Genome Coverage	~95–98% of the genome	~0.02% of the genome
Positions Read	~3 billion base pairs	~600,000–700,000 SNPs
Variants Detected	Millions per person	~600,000–700,000
Rare Variants	Yes — all detectable variants	No — only pre-selected common SNPs
Structural Variants	Yes — CNVs, inversions, translocations	Limited or none
Non-coding Regions	Comprehensive coverage	Minimal to none
Cost	$299–$999	$79–$199
Turnaround Time	8–12 weeks	3–6 weeks
Sample Type	Saliva or blood	Saliva
Future-Proof	Yes — re-analyzable indefinitely	No — frozen to chip design
FDA-Authorized Reports	Varies by provider	10+ (23andMe)
Ancestry Database Size	Small (thousands)	Very large (25M+ AncestryDNA)
Best For	Comprehensive health insights, rare disease investigation, pharmacogenetics, lifetime genetic resource	Basic ancestry, DNA relative matching, budget-conscious health screening

Real-World Implications of the Coverage Gap

The 0.02% vs. 100% coverage difference has concrete consequences. Consider these three scenarios:

Cancer Risk

The BRCA1 and BRCA2 genes together contain over 4,000 known disease-associated variants. 23andMe's FDA-authorized BRCA report tests for 3 of these variants — all common in the Ashkenazi Jewish population. If your BRCA risk variant is among the other 3,997+ possibilities, 23andMe will report a negative result. A 2019 study in Genetics in Medicine found that 23andMe's BRCA test misses approximately 90% of BRCA mutation carriers in the general population.

WGS captures all detectable BRCA variants, plus thousands of variants in other cancer-predisposition genes like TP53, PTEN, STK11, and the Lynch syndrome genes (MLH1, MSH2, MSH6, PMS2, EPCAM).

Pharmacogenetics

Your response to many medications is influenced by variants in CYP450 liver enzymes, drug transporters, and drug targets. The Pharmacogene Variation Consortium (PharmVar) catalogs thousands of pharmacogenetically relevant variants across dozens of genes. Genotyping chips test a small fraction of these — typically the most common variants in European populations. If you carry a rare PGx variant common in your ancestry group but uncommon in Europeans, a genotyping chip will likely miss it. WGS captures them all.

Carrier Screening

The American College of Obstetricians and Gynecologists (ACOG) recommends carrier screening for cystic fibrosis, spinal muscular atrophy, and hemoglobinopathies for all pregnant people or those planning pregnancy. Expanded carrier screening panels test for 100–500+ conditions. Genotyping-based "health" tests from DTC companies test for a subset of carrier variants, but miss many disease-causing mutations. WGS provides the most comprehensive carrier screening available outside of clinical diagnostic labs.

Cost Comparison Over Time

The cost gap between WGS and genotyping continues to shrink:

Year	WGS Cost	Genotyping Cost
2007	$2 million (Watson genome)	$999 (23andMe launch)
2014	$1,000 (Illumina HiSeq X Ten)	$99 (23andMe)
2018	$999 (Veritas Genetics)	$79–$199
2022	$299 (Nebula Genomics)	$79–$119
2026	$299–$999	$79–$199

Industry projections suggest WGS will reach $100 within the next 5–10 years, approaching price parity with high-end genotyping. At that point, the consumer case for genotyping may disappear entirely for health applications.

Decision Framework: Which Should You Choose?

Choose genotyping if:

Your primary interest is basic ancestry composition and DNA relative matching
Budget is a primary constraint ($79–$199 vs. $299–$999)
You want a handful of FDA-reviewed health reports (23andMe's 10+ reports)
You do not have specific medical concerns or a strong family history of genetic conditions
You dislike the idea of managing large, complex genetic data files

Choose WGS if:

You want the most comprehensive genetic health assessment available to consumers
You have a personal or family history suggestive of a genetic condition
Pharmacogenetic testing across all relevant genes matters to you
You want a one-time investment that can be re-analyzed as science advances
You are willing to engage with complex genetic information, ideally with professional guidance

Compare WGS and genotyping providers side by side

Compare DNA Tests

Frequently Asked Questions

Can I combine WGS and a genotyping test?

Yes, and many consumers do exactly this. A one-time WGS provides comprehensive health data that can be re-analyzed indefinitely. A genotyping test from AncestryDNA or 23andMe provides access to the largest DNA-matching databases for finding relatives. Since genotyping tests do not require ongoing cost, this dual approach gives you the best of both worlds: deep health insights from WGS and broad ancestry matching from genotyping. Be aware that maintaining two genetic data accounts with different companies means managing two separate privacy policies and data-sharing agreements.

Why doesn't 23andMe just offer WGS instead of genotyping?

Genotyping is significantly cheaper at scale and produces simpler, more manageable data. 23andMe's business model depends on genotyping chips that cost them approximately $30–$50 per sample in bulk. WGS would cost them $200+ per sample, fundamentally changing their unit economics. Furthermore, 23andMe's FDA authorization process was built around specific genotyping results. Transitioning to WGS would require re-authorizing their entire health report portfolio under a very different validation framework.

Will genotyping become obsolete?

For health applications, genotyping is increasingly seen as a stepping stone to WGS. As sequencing costs approach genotyping costs, the health case for genotyping weakens substantially. However, for ancestry relative matching, genotyping companies maintain massive databases (25M+ for AncestryDNA) that WGS companies cannot match. Until WGS providers build databases of comparable size — or interoperability standards emerge — genotyping will retain a role in genealogy and ancestry research.