November 16, 2022
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How Accurate Are DNA Tests?

Increasingly popular in recent years, at-home DNA test results are generally regarded as highly accurate. But just how accurate are DNA test results?
Tomohiro Takano

How Accurate Are DNA Tests?

Home DNA test kits have become increasingly popular in recent years. They make wonderful gifts for anyone interested in exploring their ancestry or learning more about how to monitor their health. But just how accurate are DNA test results?

The wrong information could lead to serious consequences for some people, especially those concerned about genetic health conditions or searching for biological family members.

The technology behind DNA sequencing has become more accessible through home testing. There’s always a possibility of human error or sample contamination in any type of testing, but assuming at-home DNA test results are analyzed by professionals in a reputable laboratory, the results are generally considered reliable.

Reasons for Taking At-Home DNA Tests

DNA testing was once only done for solving criminal cases or serious health research. With the affordability and accessibility of at-home tests, you don’t have to have a deep or serious reason for wanting to have your DNA analyzed.

Disease Screening

Some screening tests must be ordered by a physician, but you can learn a lot about your health from a simple DNA test. Specifically, sequence analysis provides information on your risk for developing certain diseases or conditions.

Being at-risk doesn’t necessarily mean you’ll develop a particular illness, but it does allow you to make lifestyle and health care choices that may help you avoid illness. Always speak with your doctor about any DNA test results that concern your health.

Establishing Paternity/Maternity

The first thing that comes to mind for many people when they think of DNA testing is paternity testing. At-home DNA test results can definitively settle familial disputes and establish biological fatherhood.

Each parent provides 50% of a child’s genes. Consequently, comparing the child’s DNA to that of its potential father(s) will result in a 99.9% match when the real father is identified.

DNA testing can also establish biological motherhood. Children who are adopted or are unsure who their biological mother is for other reasons may be able to identify their mother through a DNA database.


Learning more about personal ancestry is perhaps the most common reason for home DNA test kits.

People can trace their ancestry back up to 1,000 years while receiving estimated ethnicity percentages and mapping their family’s migration routes over the generations. DNA matching also helps customers find living relatives in addition to those from the distant past.

What Can Affect the Accuracy of At-Home DNA Test Results?

DNA test kits are simple to use. You just collect a sample, send it to a lab, and wait to get the results.

There aren’t many things that can go wrong in such a straightforward process, but a few factors can potentially produce false results.

Sample Contamination

To ensure that your sample produces accurate results, follow the directions your DNA kit provides to the letter.

If the instructions ask for a cheek swab, droplets from your tongue may yield unreliable information. Likewise, if the sample comes into contact with another person’s or animal’s DNA, it could become contaminated.

Unaccredited Laboratories

Everyone likes saving money, but choosing a laboratory based on price alone isn’t a good idea. To increase your chances of getting the most accurate DNA results, send your sample to a DNA lab that’s fully accredited and equipped with the equipment and knowledge required to perform tests correctly.


Different labs may provide slightly different results. However, this doesn’t necessarily mean that either is untrustworthy.

For example, when testing for genetic disease, one testing company may check for more disease variants than another. If company A tests for 12 genetic variants and company B tests for 24, the two sets of results could be quite different, even though both are still technically correct.

Small Databases

When it comes to learning more about ancestry, one of the biggest complaints from customers is that they don’t get enough information about common ancestors. But a lack of information in DNA test results is not the same as inaccuracy. Limitations like this are often the result of underdeveloped databases.

The reference database is the collection of all the people who have taken that specific company’s DNA test and made their information publicly available. If you’re taking a test from a newer company, there will naturally be less information available in their database.

Furthermore, there could be people with whom you share a genetic link that have opted not to share their information with others. As more DNA sequences are added to the database, more matches will be available, and more accurate profiles will emerge.

Types of Ancestry DNA Tests

There are three main types of ancestry DNA tests currently available. While each is equally accurate, the information gained from each type of test is a little different.


Mitochondrial DNA (mtDNA) is passed exclusively from the mother to her children, both male and female. Results from mtDNA tests provide information on an individual’s haplogroup. The haplogroup, also known as the deep ancestral group, establishes a family’s ancestral heritage and sheds light on the maternal ancestor’s lineage.


Y-DNA tests are only suitable for males, as Y-DNA is passed down from father to son.

The Y chromosome is responsible for male sexual traits, and all of the cells in a person who’s biologically male contain one Y chromosome. This chromosome remains virtually unchanged as it passes to each new generation.

Someone might choose to take a Y-DNA test to identify their paternal heritage or learn about the migration pattern of their paternal line.

Autosomal DNA

Tests that analyze autosomes are the most common type of ancestry DNA tests. Autosomal DNA includes the chromosomes from both parents, so analyzing it can provide information on both sides of the family tree as far back as ten generations. Autosomal DNA tests are considered highly accurate.

For a complete look at all of your ancestral connections, autosomal DNA is the best, more accurate choice.

Getting the Most Accurate DNA Results

At-home DNA test results are generally regarded as being highly accurate. Being clear on your reasons for testing, choosing the type of test that’s most suitable for your needs, and working with an accredited laboratory will help ensure that you can trust the results you get. Contact Genomelink to learn more about the benefits of having a deeper understanding of your raw DNA data.

Tomohiro Takano
Tomohiro Takano
Co-Founder and CEO