What is the difference between WGS and 23andMe?

The difference between WGS and 23andMe is depth. 23andMe genotypes about 600,000 specific SNPs (about 0.02 percent of your DNA). WGS reads all 3 billion base pairs at 30x coverage. WGS detects rare variants, structural changes, and regulatory-region variants that 23andMe misses entirely.

How much does WGS cost?

WGS costs about $400 to $1,200 for clinical-grade 30x sequencing through partners like Nucleus, Nebula, or Veritas. Specialized analysis bundles can add $200 to $500. Insurance does not typically cover screening WGS in healthy adults.

Is WGS covered by insurance?

WGS is not typically covered by insurance for screening in healthy adults. It is covered for specific clinical indications like a child with an undiagnosed disease or a patient with strong family history of a Mendelian disease. We are honest about coverage during the decision conversation.

How long does it take to get WGS results?

It takes about 8 to 10 weeks to get WGS results from kit return to analysis. Processing 3 billion base pairs and running them through clinical pipelines is computationally intensive. Rapid clinical WGS in hospitals can return in a few days, but consumer-grade WGS runs on a slower schedule.

Will WGS detect all genetic diseases?

WGS will detect most known disease-causing variants, but not all. Some rare conditions are caused by repeat expansions or epigenetic changes that standard WGS misses. For specific concerns, we may add targeted testing alongside WGS.

Can WGS predict if I will get Alzheimer's?

WGS cannot predict if you will get Alzheimer's. It can give you risk information, especially APOE4 status and a polygenic risk score. APOE4/4 carriers have substantially higher lifetime risk, but most still do not develop the disease. Genes set the slope, lifestyle decides the trajectory.

How do I choose between Nucleus, Nebula, and Veritas?

You choose between Nucleus, Nebula, and Veritas based on price, analysis depth, privacy model, and ongoing clinical interpretation. Nucleus tends to be more affordable and consumer-friendly. Nebula offers strong privacy controls and ongoing reanalysis. Veritas is more clinically oriented. We help you pick based on your goals.

Will my children inherit my variants?

Your children will inherit half of your variants. For dominant conditions, your child has a 50 percent chance of inheriting that variant. For recessive conditions, they only get the disease if they inherit a variant from both parents. Carrier screening before conception is one of WGS's highest-value uses.

What is the difference between exome and whole genome sequencing?

The difference between exome and whole genome sequencing is coverage. Exome sequencing reads the protein-coding regions, about 1 to 2 percent of the genome. WGS reads everything, including regulatory and non-coding regions where many disease variants live. WGS is now often as cheap as exome sequencing, so the field has shifted toward WGS.

How does pharmacogenomic testing change SSRI prescribing?

Pharmacogenomic testing changes SSRI prescribing because CYP2D6 and CYP2C19 status determines how fast you metabolize each drug. Poor metabolizers can build up high levels at standard doses. Ultra-rapid metabolizers may never reach therapeutic concentrations. The data lets us pick the right drug at the right dose on the first try.

What is a polygenic risk score and how reliable is it?

A polygenic risk score (PRS) combines hundreds or thousands of small-effect variants into one risk estimate for a specific disease. PRS reliability has improved substantially for coronary artery disease, breast cancer, type 2 diabetes, and a few other conditions. Reliability is still limited in non-European populations because most reference data was collected in European cohorts.

How does WGS detect copy number variants?

WGS detects copy number variants (CNVs) by analyzing read depth across the genome. Regions with extra copies show higher read depth. Regions with missing segments show lower read depth. CNVs can cause conditions like 22q11 deletion or BRCA1 deletions that genotyping misses entirely.

What is "tertiary analysis" in WGS?

"Tertiary analysis" in WGS is the clinical interpretation step where raw variants are filtered, classified, and matched to disease databases. It is the slowest and most important part of the process. Without good tertiary analysis, you have a hard drive full of letters and no medical insight.

How does APOE4 affect cardiovascular risk versus dementia risk?

APOE4 affects both cardiovascular and dementia risk because the APOE protein handles cholesterol transport. APOE4 carriers tend to have higher LDL and impaired clearance of brain amyloid. Lifestyle, exercise, and aggressive lipid management reduce both risks. The variant amplifies risk; it does not guarantee disease.

What is hemochromatosis and why is WGS useful for it?

Hemochromatosis is a recessive iron-overload disorder, most often caused by HFE C282Y homozygosity. It is one of the most common genetic conditions in people of Northern European ancestry, but is often diagnosed only after years of iron buildup damages the liver, heart, or pancreas. WGS catches it decades early.

How does WGS handle structural variants?

WGS handles structural variants better than older technologies because it reads through breakpoints and unusual regions. Structural variants like inversions, translocations, and large deletions are missed by genotyping arrays. WGS is now the standard for unexplained developmental or oncologic syndromes.

What is "incidental findings" policy in WGS?

The "incidental findings" policy in WGS follows ACMG guidelines, which list specific actionable genes (like BRCA1, BRCA2, Lynch syndrome) that should be reported even if not the original reason for testing. We discuss these policies before sequencing so you know what you might learn and can opt in or out of certain disclosures.

Can WGS predict drug side effects?

WGS can predict many drug side effects through pharmacogenomic markers. HLA-B*5701 predicts severe abacavir hypersensitivity. HLA-B*1502 predicts Stevens-Johnson syndrome from carbamazepine. CYP2C9 and VKORC1 predict warfarin sensitivity. Knowing these before prescribing prevents real harm.

What is the role of mitochondrial DNA in WGS?

The role of mitochondrial DNA in WGS is increasingly recognized. Standard WGS captures mitochondrial DNA at high coverage, allowing detection of mitochondrial disorders that cause neurological, cardiac, and metabolic disease. Mitochondrial inheritance is unique because it is passed only from the mother.

Why does Fishtown Medicine prefer Nucleus or Nebula over 23andMe for serious clinical questions?

Fishtown Medicine prefers Nucleus or Nebula over 23andMe for serious clinical questions because the depth and accuracy are higher. 23andMe is excellent for ancestry and trait fun. For pharmacogenomics, family planning, or rare disease workup, the resolution of WGS makes the difference between guessing and knowing.

TL;DR · 30-second take

Whole Genome Sequencing (WGS) reads all 3 billion base pairs of your DNA at high accuracy (30x coverage), versus consumer genotyping (23andMe) which checks about 0.02 percent. WGS reveals pharmacogenomics, rare disease risk, polygenic scores, and family-planning information that consumer panels miss.

Whole Genome Sequencing in Philadelphia: A Clinical Guide

For the last decade, "consumer genetics" has meant genotyping, like 23andMe or Ancestry. These tests look at specific hotspots called SNPs, covering about 0.02 percent of your DNA. It is like proofreading 5 random sentences in a 500-page novel. Whole Genome Sequencing (WGS) reads the entire book. All 3 billion base pairs. It covers the 99.98 percent that genotyping misses, including rare variants, structural variations, and non-coding regions that regulate how genes turn on or off. At Fishtown Medicine, we use WGS not to tell you "you have blue eyes," but to build a pharmacogenomic and metabolic map of your body that informs real medical decisions.

How does whole genome sequencing actually work?

Whole genome sequencing actually works by reading your DNA letter by letter using next-generation sequencing technology, then comparing your genome to a reference and a clinical-variant database.

Genotyping (the older way)

Technology: DNA microarray.
Resolution: Low, about 600,000 SNPs.
Utility: Ancestry, basic traits like cilantro aversion, and common carrier status for conditions like cystic fibrosis.

Whole genome sequencing (the newer way)

Technology: Next-generation sequencing (NGS), usually Illumina.
Resolution: High, with 30x coverage meaning every letter is read 30 times for accuracy.
Read depth: 100 percent of the genome (exons plus introns plus regulatory regions).
Utility: Rare disease diagnosis, detailed pharmacogenomics, polygenic risk scores, and complete carrier screening.

Why do we use WGS in clinical care?

We use WGS in clinical care for leverage, not entertainment. The data has to change a real decision.

1. Pharmacogenomics (drug compatibility)

This is the highest ROI application. Your genes dictate how your liver processes drugs through CYP450 enzymes.

Pain meds: Some people are "ultra-rapid metabolizers" of codeine, converting it to morphine instantly with overdose risk. Others get zero relief.
Antidepressants (SSRIs): Genetic matching can save years of trial-and-error prescribing.
Anesthesia: Asking "does anyone in your family have trouble with anesthesia?" is archaic. We can now know if you are at risk for malignant hyperthermia.
Statins, beta-blockers, PPIs: All have known pharmacogenomic interactions.

2. Metabolic and methylation strategy

MTHFR and COMT: These genes affect methylation and neurotransmitter clearing. A slow COMT carrier ("warrior gene") often has high focus but high anxiety, and caffeine makes them jittery. We adjust supplements like magnesium versus B-complex to match this reality.
APOE status: The most studied variant in dementia and cardiovascular biology. Knowing your APOE3, 3/4, or 4/4 status changes your lipid targets and lifestyle priorities right away.

3. Rare disease and carrier status

Family planning: You and a partner can know with certainty if you both carry recessive variants for hundreds of conditions.
Silent risks: Conditions like hemochromatosis (iron overload) are often diagnosed only after liver damage. WGS spots them decades earlier.

Who is WGS for?

WGS is for several specific patient profiles where the data clearly changes care.

The "optimizer"

You want to know exactly which supplements (B12, folate, vitamin D) you genetically need, rather than guessing. You want to know your muscle fiber type (ACTN3) to tailor your training.

The "family protector"

You have a vague family history of "heart issues" or "early cancer" and want to know if there is a concrete genetic driver like Lynch syndrome or BRCA, so you can screen on the right timeline.

The "data native"

You see the value of owning your raw data. Science moves fast. A gene that means nothing today may be the key to a new therapy in 5 years. With WGS, you do not need to retest. You just re-query your data.

Who is WGS NOT for?

WGS is not for everyone, and we are honest about the trade-offs.

The health-anxious

Genetic data is probabilistic, not deterministic. Finding a generic "increased risk" for glaucoma might damage your sleep, even if you never get glaucoma. If you struggle with health anxiety, more data can be fuel for the fire.

The privacy-absolutist

Our partners (Nucleus, Nebula) use bank-grade encryption and allow anonymous sequencing, but creating the data still creates a footprint. If you want zero digital health record, do not sequence your DNA.

Life and disability insurance considerations

GINA Act: In the US, health insurers and employers cannot discriminate based on genetic data.
Loophole: Life insurance, disability insurance, and long-term care insurance can ask. If you are planning to apply for a large policy, do that first, then sequence.

What is the strategic roadmap for WGS?

The strategic roadmap for WGS covers ordering, processing, and the deep-dive review. We partner with Nucleus or Nebula Genomics for clinical-grade 30x sequencing.

The kit: A simple cheek swab or saliva tube mailed to your home.
The turnaround: 8 to 10 weeks. This is deep science, not instant.
The deep-dive analysis:

We review the clinical findings: carrier status, pharmacogenomics, lipid risks.
We skip the noise: earwax type, ancestry, and trivial polymorphisms.
We build a personalized user manual: "Avoid these drugs. Take these forms of vitamins. Watch this lipid marker."

Your genes are not your destiny. They are the terrain. Knowing the inheritance tells us the tipping point of the spark. It tells us exactly how hard we need to work to reduce the fuel (lifestyle risk) and maximize resilience.

Scientific References

Manolio TA, et al. "Implementing genomic medicine in the clinic: the future is here." Genetics in Medicine. 2013.
Khera AV, et al. "Genome-wide polygenic scores for common diseases identify individuals with risk equivalent to monogenic mutations." Nature Genetics. 2018.
Caudle KE, et al. "Standardizing terms for clinical pharmacogenetic test results." Genetics in Medicine. 2017.
Adams DR, et al. "Next-generation sequencing to diagnose suspected genetic disorders." New England Journal of Medicine. 2018.

Dr. Ash is a board-certified internal medicine physician at Fishtown Medicine in Philadelphia. He uses Medicine 3.0 tools so your prevention plan is built on your unique genetic terrain, not population averages.

Fishtown Medicine | Diagnostics

2418 E York St, Philadelphia, PA 19125(267) 360-7927 hello@fishtownmedicine.comHSA/FSA Eligible

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Medical Disclaimer: This resource provides clinical context for educational purposes. In the world of Precision Medicine, there is no "one size fits all", the right plan must be matched to your unique lab work, physiology, and goals. Consult Dr. Ash to determine if this approach is right for you, especially if you have chronic health conditions or are taking prescription medications.

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TL;DR · 30-second take

Whole Genome Sequencing in Philadelphia: A Clinical Guide

How does whole genome sequencing actually work?

Whole genome sequencing actually works by reading your DNA letter by letter using next-generation sequencing technology, then comparing your genome to a reference and a clinical-variant database.