What is home DNA testing?


What is home DNA testing?

What is home DNA testing?

Most people nowadays are familiar with the concept that DNA contains the blueprint to our existence. However, until relatively recently, it was something that very few were aware of. DNA was first isolated by Fredrich Meischer in 1869, but it wasn’t until the 1950s, after Watson and Crick unveiled their proposed structure of DNA, that it started to be appreciated by more than just the specialists. Since then, DNA testing has arguably become an integral part of society; from ‘Jerry Springer paternity tests’, to its use in criminal investigations, popularised by shows such as CSI. You can’t help but be aware of it.

Now however, a new chapter in the use and understanding of DNA is starting to emerge. Home DNA tests are opening up science to us all, from the comfort of our own homes. Home DNA testing, also known as ‘direct to consumer genetic testing’ or ‘private genetic testing’, allows customers to make use of their genetic information to gain a wide range of insights into themselves. Home DNA kits used to be offered by only a few niche companies, but are now being sold by a wide selection of providers from around the world, resulting in lower and lower prices. As well as being able to order online, customers can now buy themselves an ‘over the counter’ DNA test kit in stores such as Superdrug, which sells 23andMe health and ancestry tests. Whether you buy online or over the counter, purchasing a home DNA kit has become as convenient as getting groceries.

If you’re already convinced and want to know more about the types of DNA test on offer, we’ve listed prices and detailed product info for ancestry, health and paternity providers. Or if none of these take your fancy, you can browse other types of DNA test that range from personality to home dna testing for your pets on our A-Z Tests page.

How do home DNA tests work?

Have you put off buying a DNA home testing kit because of the thought of having to provide a blood sample? Well you needn’t worry. Despite many sharing this concern, the reality is that blood samples are very rarely a requirement of direct to consumer genetic testing. Most simply use a sample from the inside of your cheek, known as a buccal swab, which is easy, painless and quick. All of the equipment and instructions you need are usually provided in the DNA test kit, to make the experience as convenient as possible. The few cases in which you may be required to provide a blood sample include prenatal testing, or when testing specific pets, but these are definite exceptions. In the vast majority of cases, blood samples aren’t recommended or even offered by the company providing the test.

Once you have taken your sample, it is sent back to a genetics lab. Companies offering home DNA kits separately to the actual test, differ on how much they charge for processing the sample at the lab, so make sure you check this before ordering. As previously mentioned, companies often outsource the processing of samples to a lab in a different area of the country or even a different country altogether, which can be costly if you have to organise and pay for the postage and packaging yourself. The labs that process home DNA tests should be accredited by a national agency that verifies the lab’s quality standards, which are set by the International Organisation for Standardisation (look for ISO 17025).

How accurate are results from home DNA tests?

As the provider you purchase your home DNA test from must use an accredited lab, you can be assured that the processing of your DNA samples will be done according to international standards. For relationship tests such as paternity tests, you can be doubly assured that where these are required for legal or immigration purposes, the provider must also be approved by the Ministry of Justice.

Direct to consumer genetic testing companies tend to employ those with a detailed knowledge of the studies that back the conclusions made, so they’re aware of how reliable the research is. In fact, some home DNA tests, such as those that determine paternity, can give you 100% certainty about your results. However, there are others, such as personality and health tests, that provide results based on very new research that has yet to be repeated and consolidated by further studies. Good providers will give you information on the research they based their findings on, and information about the specific genes they looked at, so that you can personally investigate further and assess how accurate the results are. The best providers will even evaluate their own research and grade the results they give you by how reliable the studies they’re based on may be.

The issue of accuracy and reliability is perhaps most significant for DNA home testing kits that are related to health, specifically for those which assess your genetic predisposition to certain diseases. Although results from these home DNA testing kits are backed by research and can give you a good idea of the sort of conditions you are genetically more likely to develop, they are far from a diagnosis. In a lot of cases, even when a home DNA test shows someone to have a higher than normal likelihood of developing a disease, it may only be 1% higher than average, and therefore may still be unlikely overall. This is because DNA testing purely assesses your genetic predisposition, whilst in reality, other biological and environmental factors play equally important roles. If you’re interested in purchasing a health home DNA testing kit, but want more information, read our previous article, ‘What are the pros and cons of genetic screening?’.

How much do home DNA tests cost?

Another reason many people are wary of taking a home DNA test is the price, but this is not as high as you might expect. As direct to consumer genetic testing has become more accessible, the cost has decreased dramatically. It is now a lot more affordable than it was even a few years ago, due to improvements in technology, as well as increasing competition in the market. Prices differ according to what the test includes, the proportion of your DNA that is actually tested and the number of analyses and extra services provided. This means prices for home DNA testing can vary according to category. For example, health testing tends to be more expensive than paternity testing, as it usually includes detailed analysis of a higher number and wider range of genes.

Prices within test categories can also vary quite significantly. This may be because one provider can simply afford to offer the same service at a lower price. However, the phrase ‘you get what you pay for’ often applies in the case of direct to consumer genetic testing, as often a lower price means you will end up paying extra for services that are already included in the price of only slightly more expensive home DNA tests. A common example of this is having to pay extra taxes and postage at the checkout, or for returning your samples to the lab. These can be especially expensive if the lab is based in another country, which is often the case when buying from the UK. Read our article, ‘How much does a DNA test cost’ for more information on the costs involved in purchasing a home DNA test kit.

How and when will I get the results of my home DNA test?

When it comes to the length of time it takes to get your results, when publishing times on their websites, providers consider this period to start when they receive your sample, not from when you order or receive your kit. Again, if the genetic testing lab is based abroad it may take longer for them to receive your sample, so this something worth considering when ordering an online DNA test. The time taken to get these results varies considerably, depending on which type of DNA test you take and which company you are using. However, most companies won’t take longer than 12 weeks, and those that take that long tend to be the ones that sequence your whole genome, as this requires analysis of a lot more genetic information than most tests. The majority of online DNA test providers offer results within two weeks, and many provide the opportunity of an express service, for an additional fee, which in some cases allows you to receive results the same day.

Results are most often delivered online, regardless of whether you purchased a DNA test online or received an ‘over the counter’ DNA test. This usually requires you to register your kit on the company’s website, a process which is mostly made quick and easy and often gives you access to interactive online tools, designed to help you understand and interpret your results. If you want a hard copy of your personal DNA test results from a company that only provides a digital copy, you can sometimes print this document yourself, but you’ll often have to pay extra to be sent an official hard copy.

What do home DNA tests actually test?

To provide you with your home DNA test results, direct to consumer genetic testing companies can look at several different areas of your DNA. Which specific part changes depending on why you’re taking the test. The most common section of your DNA that is analysed is a part known as your ‘exome’. Although this only makes up around 1% of your whole genome (all of the DNA you have), it varies greatly from person to person. The rest of your DNA varies very little from person to person, and is not thought to have a significant effect on many of the aspects that make you the person that you are. With this in mind, only a few companies offer Whole Genome Sequencing (WGS) using a DNA home testing kit. These provide customers with their DNA sequence that includes every single gene in their body, and may prove useful in future, as we find out more about how DNA works. However, due to the size of an individual’s DNA sequence, the price for undertaking it using home DNA testing is, unsurprisingly, significantly higher. This type of direct to consumer genetic testing is also not currently available as part of any ‘over the counter’ DNA test, and can therefore only be ordered online.

When companies analyse your exome, they’re looking for variations of your genes which are linked to different characteristics. Genetic variants can tell you a wide range of things; from whether you’re more or less likely to exhibit certain personality traits, to how likely it is that your baby may suffer with Cystic Fibrosis.

If you’ve purchased a home DNA testing kit before, the provider may have given you a raw copy of your genetic variant data with your results. It’s worth noting that other companies offer services whereby they scan this raw data to give you additional results. This means that you can find out additional information without having to provide another sample. This can end up being much cheaper than taking a second test that requires a sample, so if you’ve taken a test and you want to take another, do investigate this option!

Will I always receive the raw data from my personal DNA test?

When you take an online DNA test or ‘over the counter’ DNA test, the provider won’t always give you your raw genetic data with the results. Sometimes you’ll be able to download this raw data for free, or in the case of 23andMe, when you go to the site of a provider whom can analyse 23andMe’s data, you can enter your 23andMe credentials to allow them to have direct access to that data on 23andMe’s servers.

For health and ancestry testing, the raw data will often be in the form of a list of genetic variants. For relationship DNA testing (e.g. paternity testing), providers tend to give a list of the markers that led to a positive or negative result. It’s worth noting that some providers will charge you a fee for giving you your raw data, but bear in mind that you have a right for a copy of this data, so don’t let any companies tell you that you can’t have it.

If you have concerns about insurance companies gaining access to your genetic data, there are laws in place to protect you. If, for example, you find out that you have a higher likelihood of developing Alzheimer’s disease, insurers are not allowed to use this information to increase the price of their policy or prohibit you from purchasing it. Using someone’s genetic data to disadvantage them has been unofficially termed ‘genetic discrimination’ and is also an issue for the workplace…

The EU Charter of Fundamental Rights states that any discrimination based on any grounds such as “genetic features” shall be prohibited. This prevents employers from using any genetic information about an individual as a reason not to hire or to fire them.

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