How To Interpret DNA Test Results
DNA testing has come a long way since it was first introduced on the market as an at-home option. Here at YourDNA, we take pride in keeping up to date with the latest developments when it comes to analyzing your results so that you can rest assured you get the knowledge you desire about your health, genealogy and even paternity.
DNA tests have become widely popular over the last several years, as more people are determined to discover their ancestry.
Companies like 23andMe, AncestryDNA, MyHeritage and Family Tree DNA offer cost-effective at-home testing that delivers results to your email inbox within a few weeks.
Many focus on origins and ethnic mapping but there are some tailored to discovering health issues, including identifying variants that may signify whether a person is a carrier for specific diseases.
Other DNA tests are used to determine paternity when it’s called into question. Regardless of the type of test you take, knowing how to interpret the results is beneficial in understanding the reports.
Interpreting DNA Test Results
After you’ve taken the DNA test, whether it’s for ethnic mapping, health, weight or even paternity-based, you’ll receive a report that lists the findings.
These reports are highly detailed, and while they do use a lot of scientific jargon, they’re easily broken down into layman’s terms so you can understand the specific components.
The more specialized the test you take, the more detailed your end results will be. Most reports come with a key that explains each factor and how it relates to your DNA.
Are DNA Results Accurate?
There are a lot of factors that go into evaluating your DNA and external elements that can skew your results. However, the testing itself is precise, so you can rest assured that your results will be fairly accurate, though they will never be 100 percent.
Several stories have emerged about people who have taken DNA tests from different companies and ended up with varying results. Does this mean that one is more accurate than another?
No, it simply means that these companies are likely testing different factors in the DNA strands. Typically, your ethnic estimate will generally be the same with slight variations among companies, particularly if they dial into specific regions.
Interpreting Possible Matches
When it comes to interpreting possible familial matches, DNA companies essentially compare common DNA among those who submit their samples. By doing this, they identify a similar code that may indicate your relationship to someone else in the database.
Many of these matches are distant, which makes sense because a person’s ancestry dates back thousands of years and having similar ancestors will lead to these matches.
Siblings and first cousins will have a higher percentage of matched DNA, where distant cousins, aunts and uncles will have lower percentages, including some that come in with under 1 percent match rates.
Do You Need Genetic Counseling?
Genetic counseling is a personal choice that each person has to make, though it can be beneficial for some more than others.
For example, if you test positive for specific genes related to Alzheimer’s or other diseases, you’ll want to know the impact that this can have on your current and future family members. If your tests indicate that you’re not a carrier, you likely won’t require the services of a genetic counselor.
What Is a Genetic Counselor?
A genetic counselor is a medical specialist who is well-versed in genetics and how they affect you and your direct descendants. They can help you navigate your results and even recommend more testing that provides additional insight into inherited conditions and diseases.
You’ll also have access to information that can help you make informed decisions about your family, such as whether it’s a good idea to have children or how to go about preventing potential occurrences.
Not all genetic counselors work in the same niche, some choose to specialize in different areas such as neurology, cancer, pediatric and prenatal fields. Others prefer to dedicate themselves to research with the hopes of advancing medical knowledge to help even more with genetic conditions in the future.
What Is a Positive Test Result?
A positive test result indicates different things for different tests.
For example, if you’re taking a health-based DNA test, a positive result could mean that you carry specific genes that are passed down from your parents and other ancestors, particularly relating to diseases such as cystic fibrosis or dementia.
Positive results don’t necessarily mean that you’ll develop the disease, but your children or grandchildren may down the line. With a paternity test, a positive test result simply means that the child tested against your DNA has proven to be related to you.
What Percentage Does a Paternity DNA Test Have to Be to Be Positive?
In order to be considered a positive match, a DNA test has to range between 99 and 99.99 percent. Anything below that and the results will display that the person is excluded as the father.
This is a scientific term that basically states the male tested cannot be accepted as the biological father because the science does not support the relationship.
What Does 99.99 Mean on a DNA Test?
Receiving a 99.99 percent match on a DNA test signifies that there is very little doubt that the person taking the DNA test is the father of the child. This is measured through the Combined Paternity Index, or CPI.
However, the test results will not outright say you are the father, it will be scientifically stated as “not excluded,” which means your genetic makeup matches the child’s with enough accuracy to determine that you’re the alleged father.
What Is a Negative Test Result?
A negative test result when it comes to DNA testing, like a positive result, can have multiple meanings.
However, it typically means that there are no genetic changes or mutations that indicate the presence of, or that a person is a carrier of a certain disease. It can also mean that a person is not at an increased risk.
For most negative tests, further testing is necessary in order to confirm the result. This should typically be done in a lab under the guidance of a qualified physician, especially if it warrants further review.
What Is an Inconclusive Test Result?
An inconclusive test result can be frustrating because it gives no real insight into your DNA either way.
It cannot tell you if you’re at a higher risk for certain diseases but it can’t rule it out either, so you’re left with no real answer and no means of evaluating your results. If you end up with an inconclusive result, don’t despair.
Instead focus on those that are conclusive and consider scheduling another DNA test as soon as you can if you’re that dedicated to wanting to learn more about your genes and potential risk factors. If you did an at-home test, maybe you’ll want to schedule one with your doctor to eliminate another incident of inconclusive results.
Why Would a DNA Test Be Inconclusive?
There are several reasons why your DNA test might be inconclusive, depending on the type of test that you’re taking. For paternity tests, any range that extends from above 0 to 98.99 percent is considered inconclusive.
This often occurs because there isn’t enough DNA to compile or there aren’t enough matches in the DNA to come up with a positive result. For this reason, if the paternity isn’t verified, but the lab technicians need more data, they’ll include the mother’s DNA in the test as well.
This makes it easy for them to eliminate the mother’s DNA to hopefully form a stronger match with the potential father. It can also go the other way and completely eliminate him as a potential candidate.
For health tests, on the other hand, the factors are a bit different so there are varying reasons why the results can come back as indeterminate. The most common reason is that there are natural variations that occur in a person’s DNA that aren’t necessarily related to a disease or disorder.
The best way to overcome this is to have family members undergo the same testing, both those affected and those unaffected to help clear up results.
Another reason for indeterminate results is contamination of the DNA sample. This can happen when the sample is handled improperly, whether intentional or not.
Finally, inconclusive results may occur if the sample size is too small. In cases of contamination or too small of a sample, you’ll have to do the testing once again.
Interpreting Paternity DNA Test Results
If you’ve had to undergo a paternity DNA test, you are probably familiar with the process which involves a cheek swab of both the alleged father and the child or children in question.
The test is pretty straightforward and compares both sets of DNA looking for commonalities that indicate the presence of a relationship between the two.
Paternity ‘Not Excluded’
Paternity ‘not excluded’ is a scientific term that indicates the probability of paternity is enough that the man is not being excluded as being the father of the child. This is only listed if the match is between 99 and 99.99 percent. These results are the closest you’ll get to a positive.
Paternity excluded means that there is not enough evidence to support a relationship between the alleged father and the child. In this case, a court would rule that the person is not the father and would not recognize him as the biological parent.
Can the Probability of Relationship Ever Be 100%?
The probability of paternity can be 100 percent, but not in a positive manner. If the result is 0 percent, it’s considered that the person tested is 100 percent not the father. There will never be a 100 percent positive result; the highest match for a paternity ‘not excluded’ result is 99.99 percent.
Interpreting Ethnicity DNA Test Results
All of the at-home DNA tests you take will include your ethnicity results, pinpointing the regions that your genetic makeup indicates.
For some people, learning their ethnic regions comes as a great surprise, while others are confident in theirs, knowing their genealogy quite well. These results give you an insight into where your ancestors originated from.
They can be limited to a specific region or spread across the globe, depending on your roots. In general, you’ll see a list of regions with a percentage next to them to indicate how much of your makeup comes from that ethnic region.
Some results may even include low confidence regions, which are those that the test cannot pinpoint with certainty using your DNA. They are often the lowest percentages on your list.
How Do Maps From Different DNA Testing Companies Compare?
Your ethnicity estimate is a ballpark figure but could vary among companies. If they’re doing the same test, how could they possibly be different you might be wondering.
The truth lies in the number of regions that each DNA testing company uses. MyHeritage DNA, for example, uses 42 regions while 23andMe has continued to add more than 100 over the years and includes sub-regions to more accurately pinpoint your ancestry.
Interpreting Ethnicity Maps
The ethnicity maps for DNA testing companies tend to be interactive, meaning you can click on the regions to get more information about the area and what your ancestors were like in the past as well as how they landed in that region.
The ethnicity maps also tell you which countries fall into those regions and some companies even pinpoint the exact location your DNA outlines.
What Are Reference Panels?
Reference panels are a means of proving your ancestry with 100 percent certainty. They are a glimpse into an extensive family history that includes those who date back thousands of years.
If you’re certain of your history, you can apply to be on the reference panel and log your name for future generations to discover. It’s not a simple task though, and not just anyone can do it.
You do need a paper trail that proves your connection and only after this is established, you will need a DNA test as confirmation.
Interpreting Health DNA Test Results
One aspect of DNA testing that tends to spark a lot of emotion is testing for health factors.
This is especially true if you’re looking to see if you are a carrier for a disease or condition, or if you have inherited gene mutations that indicate you’ll potentially or definitely develop a condition or disease in the future.
Is It Possible to Get False Positives?
When it comes to taking any kind of test, there is always room for error. For this reason, there is the potential that false positives may occur.
One study even identified a 40 percent error rate that led to false positives. This only exemplifies the importance of going over your results with a qualified professional.
What Does Zero Variants Detected Mean?
When the test results say “zero variants detected” it means that there are no mutations detected that signify an increased risk of a specific condition or disease.
What Does It Mean to Be a Carrier of a Disease?
Being a carrier means that your DNA includes gene mutations that could lead to the future development of the specific condition it’s testing for. It does not mean that you will definitely develop the disease, it only means that you have the potential to in the future.
Some people are carriers and never have any symptoms or developments. On the flip side, some people aren’t carriers and do develop conditions or diseases later in life.
Should You Analyze Your Health DNA Test Results or Let a Professional Analyze Them?
While you’re given enough information to determine your results on your own, sometimes the context is best analyzed by a qualified doctor. For this reason, most companies have a fine print text that says the results are only for educational and informational purposes.
Instead of trying to figure out what your markers mean for your future, seek out the help of a professional to evaluate your results.
What to Do If Your DNA Reports Are Not What You Expected
Sometimes the results you get are exactly what you suspected, while other times they may throw you for a loop.
If you’ve spent your entire life hearing about how your great-grandparents are from Ireland, you might undoubtedly be a bit surprised if your results show up showing a very low percentage of Irish ancestry.
That doesn’t mean that your family lied to you, it simply means you didn’t inherit much of that ethnicity.
It’s possible that you and your siblings have different percentages of ethnic makeup, and this is very normal. You do get 50 percent DNA from each parent, but that DNA can and often does differ among children. This is the reason why you may have brown eyes, but your sibling’s are blue.
Other things that might take you by surprise are the presence of genes for inherited conditions or increased risks for serious diseases, even if there is no history in your family. One thing to note, though, is that the presence of these markers does not necessarily mean you’ll develop the disease.
Some just outline the risks, so don’t be rash in making any decisions about your present or future. Instead, take the opportunity to speak with your doctor or a genetic counselor for a more accurate representation of what the markers mean for you and potentially, your family.
Helpful Tools to Analyze Your DNA
If you find that you need extra help or want more information than you received, there are a few sites that are helpful when it comes to analyzing your DNA reports.
They all work essentially the same way: you upload your raw data and then select the services you want to use. Some are free while others charge a fee for their services.
Some also offer a combination of free and paid options so you can return at a later date and upgrade your services.
GEDmatch, found at gedmatch.com, has several options on their site. After uploading your raw data you can choose from varying analyses including:
- Matches including one-to-one, one-to-many, X one-to-one
- Phasing, including phasing for DNA that you didn’t inherit
- Relationship Tree projections
The company offers two services: basic memberships, which are free and Tier 1 utilities which are available for $10 monthly as of January 2019.
GEDmatch works with analyses from 23andMe, AncestryDNA as well as FTDNA, though some services are limited to 23andMe only. You’ll need the kit number to get started.
Found at geneticgenie.org, this site is very specific in the analyses that it provides. It also only works with 23andMe tests, so be aware of that if you’re trying to use their services. You can upload your raw data to receive your:
- Methylation Analysis
- Detox Profile
At the present, there are no costs associated with using these services, though they do ask that you consider donating to help offset the costs of maintaining the website.
If you’re looking to research and learn more about what your DNA profile says about you, you’ll get a lot of information from promethease.com. Here you can upload raw data from nearly any DNA testing service, which makes it a universal solution.
The site does warn that the detailed reports are for informational purposes only and to speak with a doctor or genetic counselor about any concerning issues that may appear. Some of the information you’ll receive:
- Genealogical details
- Health information to gauge genetic risks
- Titles of scientific literature to reference for better understanding
The site doesn’t take long to generate your report, you’ll have access to it within 15 minutes. As of January 2019, the reports cost $12, though you can add another data file to create combined reports for an additional $4.
If you want the combined reports, you have to pay for them at the same time.
Interpretome works with data files from two specific companies: Lumigenix and 23andMe. It gives a comprehensive analysis that determines:
- Your health risks for specific diseases including Type 2 Diabetes, Alzheimer’s and Lewy body disease to name a few
- Genealogy results
The site cautions against taking the results as diagnostic, rather their reports are meant to be informational in nature for educational purposes only.
Genomapp is an app designed to work on your Android or iOS device. You upload your DNA data to get your comprehensive report in just 5 minutes. Things included in your report include:
- Inherited Conditions
- Complex Diseases
- Blood Groups
There is a small fee associated with exporting your report as a PDF, though it tends to be hidden until you request it.
Whether you’re taking your first DNA test or comparing your results against different companies, you definitely want to know how to interpret the results to get a full understanding of the factors that go into testing.
Your DNA is processed into what’s known as raw data, which you can plug into one of many tools for a more thorough explanation of what your genes are trying to tell you.
Genealogy and health DNA tests go into far more detail than your standard paternity tests because they’re seeking out the information held within your DNA strands, whereas paternity tests are looking for commonality.
Knowing how to interpret the results gives you more power to make educated decisions about your current lifestyle and your future.