Whole Genome Sequencing
You see two DNA test kits. One is priced at $199, while another is priced at $700. Obviously, you go for the $199 kit, right?
Well, not if you want your WHOLE genome analyzed. For that, you’ll need the newest form of high throughput, next-generation sequencing.
While whole-genome sequencing (WGS) is much more expensive than typical DNA tests, WGS offers way more potential results. In this is article, Genomelink editors will tell you why whole-genome sequencing kits are better than tests from 23andMe, AncestryDNA, and MyHeritage, how they are better, and where you can get one! Check it out!
What is Whole-Genome Sequencing?
Whole-genome sequencing is exactly what it sounds like - using your spit sample or a cheek swab, this test will analyze your entire genome. While the human genome used to take billions of dollars to analyze, new techniques allow the entire genome sequence to be read for less than $1,000!
You might be wondering how whole-genome genetic testing is any different from the methods used by 23andMe, AncestryDNA, and MyHeritage. That’s a good question! Here’s a simple breakdown:
Single-Nucleotide Polymorphisms (Typical DNA testing method)
The “typical” DNA test kit looks at around 700,000 single nucleotide polymorphisms (SNPs). These “snips” - as they are jokingly called - consist of two complementary nucleotides at a specific position within your DNA. These genetic variations are important, as they have been linked to a wide number of traits and health conditions. Based on a number of specific SNPs, this testing can assign you an assumed genotype that can be related to different traits.
For example, cystic fibrosis and other genetic diseases are often caused by SNPs. There are several mutations with the cystic fibrosis gene that cause the resulting protein to malfunction. This malfunctioning protein ultimately causes the symptoms of the disease. Since you get 1 gene from your mother and 1 gene from your father, you have 2 copies of the cystic fibrosis gene. However, you need 2 malfunctioning copies in your genetic makeup in order to show the symptoms of the disease. People with only 1 copy are considered “carriers”.
The reason SNP testing (especially for genetic diseases) works so well is that scientists have identified the most common SNPs - or singular mutations - that cause many cases of the most common genetic variants. Therefore, to save time and money, DNA testing companies tend to only test a few hundred thousand SNPs that have been associated to certain traits, conveniently available on Illumina sequencing chips.
However, the 700,000 SNPs measured by common DNA testing companies are only a microscopic portion of your DNA. Considering you have over 3,000,000,000 nucleotide-pairs in your DNA, most DNA testing companies are only measuring about 0.023% of the total. You may have random, uncommon mutations in the rest of your genome that SNP DNA sequencing cannot find. Imagine if you could learn about the variation present in 100% of your DNA...
That’s where WGS comes in. Instead of looking at the most commonly studied SNPs in a tiny portion of the genome, WGS reads every single molecule in your DNA sequence - all 6 billion of them. Laboratories do this using new sequencing technologies based on the same “chip” technology as traditional SNP testing - though on a much larger scale.
As a consequence, a WGS test will get you far more results than with a traditional SNP test. Why? Because there are simply far more measurements taken when the whole genome is analyzed. SNP tests may be missing a large portion number of variants specific to your health and wellbeing that are not common SNPs in the wider population.
In fact, most SNPs even fall within the “exon” - the part of your DNA that actually produces proteins. Some companies offer “whole-exome sequencing” kits, that only look at these regions. Exons only account for around 3% of your total DNA. The other 97% is made of “introns” - curious spacers between exons. However, there is now a lot of research investigating the role and purpose of this “extra” DNA. Large scale studies of introns in sequencing data are showing that up to 50% of all genetic disorders may be caused by mutations in this area.
With whole-genome sequencing, most companies offer life-time updates or updates via subscription service on all the scientific studies related to all the mutations you carry. If you get in now, you will be at the cutting edge of science. Plus, many of the whole-genome testing services listed below allow you to be a part of massive research studies in human genetics (or even get paid to participate!).
What Makes WGS Better?
While science has been largely focused on exons and the most common DNA mutations, as the science progresses it will open many opportunities for individualized medicine within the health care industry. Not only will scientists be able to better diagnose rare genetic conditions, but they will also be able to better predict how your body will react to medicines. This will be far more accurate and predictive than standard genotyping methods.
Though there is a lot of science to be done, eventually the entire genome will likely be understood to play some role in health and wellbeing.
Whole-genome kits often come at a standard “30X”. This means the test is repeated 30 times to ensure that the genome is read accurately. Since reading individual molecules is an extremely difficult task, this makes sure that the machine accurately records each nucleotide in its proper sequence. This makes it one of the most accurate methods for predicting health conditions and ancestry testing.
Plus, with WGS testing you can find so-called “de novo” mutations - or mutations that were not inherited. Rather, these mutations are created by errors during the replication process. As the science of bioinformatics progresses, we will begin to get a much clearer picture of how these rare mutations play into things like pharmacogenomic effects of medicines, rare diseases, and lots of information related to public health in general.
In ancestry testing, WGS also offers an advantage. Because it measures far more genetic variants (every base-pair you have!) it can more accurately predict how your genomic information compares to the reference genome in the data set. This offers you a high-resolution image of your family history and can connect you more accurately to family members.
More Genetic Material Analyzed
WGS looks at your entire genome, and document the exact sequence. The sheer volume of genetic sites analyzed means you will get far more than the “common” variants found in SNP tests. Your genome contains hundreds of thousands of SNPs that are unique to you, and are hard to detect in traditional SNP testing. By contrast, if you get your entire gene documented, you will have access to all traits and correlations, as they are uncovered by science.
Essentially, we are at the very tip of the DNA iceberg. As we go further and further down the rabbit hole, scientists are going to find all sorts of correlations in your DNA. This will lead to more causation studies - which will illuminate exactly how these previously unstudied regions of DNA are contributing to health traits, nutrition traits, and general wellbeing. Plus, the entire science of whole-genome sequencing opens up the enormous possibility for individualized medicine.
How Much Does Whole Genome Sequencing Cost?
Like the wider DNA testing kit market, there are several different pricing strategies being used by different companies. Essentially, each company is trying to mitigate the higher sequencing costs of WGS in its own way. You can get a breakdown of the prices of three major WGS companies here:
$599 - $1,399
Dante Labs works on a “pay-as-you-go” model. A basic WGS test with 30X coverage costs $599. The report you get analyzes a wide-variety of common SNPs. For those with a family history of certain conditions or just increased interest in a specific condition, Dante Labs also offers “add-on” tests. If you really want to dig deep, they also offer a 120X test that is super accurate and may be able to help your doctor diagnose a rare condition.
$299 - $1000
Nebula Genomics works on a subscription model. Your initial test and results are $299, but you must pay a subscription fee to access the Nebula platform. The Nebula platform operates as a literature-retrieval service - connecting you to all sorts of scientific studies related to your genetic data. This allows you (or you and a doctor) to do your own data analysis with help from Nebula. Plus, Nebula Genomics is using a system of blockchain to store your DNA. This means that your genetic data is safe. It also offers the opportunity to get paid by participating in research studies!
$599 - $3,599
Veritas Genetics requires that you have a physician working with you to interpret and analyze your results. Very focused on health-related traits, the company even offers an advanced genetic analysis of specific genes and conditions to help your doctor determine if you are suffering from a very rare genetic condition. Unfortunately, Veritas is currently unavailable in the United States, though the company says they are working on a complex foreign funding rule that is preventing them from selling to the U.S. market.
If you are interested, read our full review of WGS testing companies and how they are advancing human genetics.