As the science behind Family DNA testing has become more refined, the curiosity behind our personal origins has exploded in recent years. Millions of people are adding to a worldwide database that is playing a global game of connect the dots through DNA analysis.
Family DNA tests allow small snippets of your DNA to be analyzed so that your family ancestry and genealogy can be traced back several generations. You can also use the information provided in many tests to learn where living biological relatives are today.
The basics of Family DNA tests
There are three kinds of DNA tests that are used to determine ancestry and genealogy.
The most common of these is the Autosomal DNA test. It is the test used to determine ethnicities/biogeographical origins.
You get half of your autosomal DNA from your mother and the other half from your father so it can be used to track genealogy on both sides of your family. The main drawback is that because of the way autosomal DNA is inherited, it can only be used to trace heritage back about six generations.
Y-DNA or Y-Chromosome test allows you to go back 10 generations or more because the Y-DNA passes unchanged from father to son. This means you can trace your paternal lineage and help you sort out individuals with the same name or similar surnames into family groups.
Women don’t have Y chromosomes, so a female who wants to trace her paternal line will need to have a Y-DNA sample taken from her father, brother, paternal uncle, male cousin on her father’s side, or a nephew (a brother’s son).
Mitochondrial DNA, also known as mtDNA traces a direct maternal line. Mothers pass mtDNA to all of their children, but only daughters pass mtDNA to the next generation.
Genealogists use mtDNA for maternal tracing much the same way that Y-DNA is used for paternal tracing. The good news is that mtDNA allows you to go just as far back in your family tree as with Y-DNA testing.
Depending on how thorough you want to be or what your genealogical goals are, you may need to have all three tests performed.
While Family DNA testing is a highly useful tool for tracing your ancestry, there are some things to take into consideration before you submit to a test.
Family DNA testing works best for people with European ancestry because most of the data already collected comes from people in that geographical part of the world. That means a large part of the world’s population must rely on less detailed profiles when they order a test.
However, this is slowly changing as more people of Asian and African descent take DNA tests.
In addition, when you submit your DNA, you are also by proxy submitting your family’s DNA as well, whether they have consented or not.
Why is this important? Look no further than the example of the “Golden State Killer” who was caught because a distant relative use a service called GEDmatch. Privacy issues need to be considered, especially if your family is sensitive about those types of things.
Family DNA testing may also turn up something you don’t want to know. According to a recent Bloomberg story, those types of surprises happen so often that 23andMe integrates training on how to deal with customers who call in and are devastated by certain results.
At home DNA testing kits
The vast majority of DNA ancestry testing kits are sold online or in drug and department stores for use and testing at home. The industry has matured to the point where the kits are easy to use, non-invasive, simple to send in results, and simple to log on to a private server to get results.
Furthermore, all companies take customer privacy seriously, so they go out of the way to make sure that your individual genetic data is protected to the highest degree possible.
However, some companies may opt to share generic and cumulative data for a variety of purposes so it’s best to be sure you are comfortable with this or there is a way to opt out from sharing before you submit a test.
Costs start at about $49 and go up to a couple of hundred dollars or more, depending on if you choose several possible add-on features (i.e. health and fitness, etc.) or want more than one of the three types of primary tests (autosomal, Y-DNA or mtDNA).
What will I see on my Family DNA test results?
Different testing companies will yield different results, but in general you will get information about your genetic ethnicity estimates, cultural roots and DNA matches that link you to others who have taken the test for your particular company may also be revealed.
Depending on how hard you want to work at it, your results can either be used as a starting point for more research and to dig deeper into your family tree, or it will provide enough answers to satisfy your curiosity.
Depending on the test you choose, your DNA test results also provide information that’s recent if you take an autosomal test or more focused on a 10,000 to 50,000 year time frame if you take a Y-DNA or mtDNA test.
Best DNA tests for ancestry
Identifying what the best tests for ancestry can be a bit tricky. There are a ton of online reviews and sites filled with anecdotal information about the pros and cons of various tests.
Certain tests will tell you different kinds of information that may be more useful for your particular situation, so what’s best for one person may not be the best for another.
Just like any other important decision, the smart thing to do is to research the various testing companies and reach conclusions about which one to use based on your personal ancestry and genealogy goals.
How ancestry DNA tests work
The first step in taking a DNA test for ancestry is to submit a sample. When you order a test, you’ll get a cheek-swab kit or a spit kit.
Collecting a sample is usually done by wiping a swab on the inside of your cheek for several seconds. A mouthwash kit provided by 23andMe is also simple to use.
You swish a supplied rinse in your mouth and spit it back into a container. Samples are then returned to the company which does an analysis on your DNA and supplies you with results, generally online, in 2-8 weeks.
How accurate is an ancestry DNA test?
If you are of European descent, there’s a good chance your results can be measured to more than 99% accuracy. If you are from other regions of the world where less data has been collected and can be used to analyze your DNA, then it will be something less.
This is rapidly changing as millions of people undergo tests and help to build a global database. Some companies even offer updates and more data becomes available after you take your DNA test.
The other thing to consider is the type of test you take. In some cases, an autosomal test will be just fine for your needs.
But at other times, if you are serious about results and have some ancestral challenges, you should consider a Y-DNA test or an mtDNA test.
If you want to put in the work, the best way to use your DNA test results to identify your ancestry is to combine them with traditional genealogical research methods.
DNA tests to find out heritage
People often confuse ancestry and heritage. While they may appear similar on the surface, it’s useful to note the differences.
Ancestry is the historical evolution of a person based on past family relationships. Heritage deals more with culture.
In other words, ancestry is biological while heritage is more concerned with social values. In this regard, there really aren’t tests for heritage, but using tests for ancestry, research can be done to uncover the heritage of relatives from past generations.
Sibling DNA tests
Sibling DNA tests are performed when an interested party wants reassurance about relationships with a person’s siblings or to create documentation that can be admitted in court.
“Peace of mind” tests are available online and in drug stores, but a “legal” sibling test must be carried out following chain of custody rules by a doctor, lab and/or government approved lab testing service.
The first step in performing a sibling DNA test is to determine what you want to have tested. Siblings may be sure that they have the same mother and want to confirm or deny they have the same biological father, or they have the same father but want to confirm or deny if they have the same mother.
It is important to establish the parameters and goals of the test up front so that the right test can be performed.
To get the best results, if a person knows for sure that they definitely share one parent with a possible sibling, that parent should be included in the testing process. This allows the lab to distinguish DNA from the known common parent with DNA that might be shared from the other parent.
Genetic markers are compared with from the tested parent help to reconstruct DNA from both the parent and the siblings. When the tested parent’s DNA is removed, if the remaining DNA is a match in both children, then they are likely siblings.
With a peace of mind test, each participant will swab in the inside of their cheek to collect a buccal sample. Collection is simple, painless and only requires lightly brushing the inside of a check for about 10 seconds to collect a sample.
After a cheek has been swabbed, the sample is placed in a container sent to a lab for testing. When a legal test is required, an appointment must be made at an approved facility where either a buccal sample or blood sample will be collected.
Paternity DNA tests
Because a child gets half of his or her DNA from a mother and the other half from a father, DNA paternity tests can be extremely accurate in determining who the biological parents are when samples are taken from the mother, father and the child.
A lab will be able to match a mother’s DNA and then the remaining DNA is matched against the alleged father. If it does not match, then the person can be excluded from being the biological father.
In cases where a mother or a father is not available for a sample, it is still possible to produce an accurate result through more extensive analysis. When an alleged biological father is missing or deceased, testing can be performing on grandparents, siblings, aunts or uncles or through family reconstruction.
Paternity tests are done for either “peace of mind” or for legal reasons. Using an at-home test is acceptable for peace of mind testing which not only establishes relationship links but can also be used to track heritage and ancestral information as well.
When a paternity test is done for legal reasons, it must be conducted using strict chain of custody rules when collecting a sample.
This means the results of the test can be used in court or with government agencies for several reasons such as collecting child support, validating a relationship for Social Security or Survivor benefits, establishing a relationship for inheritance or probate issues, in a criminal case, adoption proceedings or to complete a birth certificate, among others.
Do paternity DNA tests work?
Absolutely. But there are still times when errors can take place. For example, the testing industry only requires a 99% probability of paternity to be achieved.
But this also means that an identified DNA pattern could be possessed by one out of every 100 men. Even a 1% margin of error is too great for such an important test.
If a paternity test is important enough to take, then you should find a lab that promises a much higher degree of accuracy, such as 99.99%.
You should also know that paternity tests can be administered even before a baby is born. This is because fetal DNA combines with a mother’s DNA by passing through the placenta and into the mother’s blood stream.
As such, noninvasive tests for paternity can be performing as early as 9 weeks into a pregnancy. A prenatal DNA test can also be performed as part of an amniocentesis which is performed during the 16th week following conception.
Another option is to perform a paternity test immediately following birth. The baby must be cleaned up and it’s important that the baby’s mouth be free from meconium, amniotic fluid, breast milk, or formula when doing the DNA collection because a cheek swab is used to collect a sample.
How accurate are DNA tests for siblings and paternity?
Sibling DNA tests are accurate, but not as accurate as DNA paternity tests. This is because siblings are not as closely related to each other as they are to their parents.
The more genetic locations that are tested will improve the accuracy of the test. Most companies check 16 locations as a minimum, but it is possible to check up to 68 locations.
The more locations that are tested will probably increase the cost of the test, but it may be worth it depending your situation.
However, overall passing specific DNA from a parent to a child can vary widely from child to child. Because of this variance, the amount of DNA that siblings share can be much lower than the amount of DNA shared between a parent and a child.
When this happens, there are fewer markers to compare and that can impact the accuracy so that it is less than 100% certainty.
This means that when results are returned to test subjects, they will often come with a Combined Relationship Index (CRI) between 0 and 100. In a sibling DNA test, because there is not as much DNA shared in common between siblings, CRIs often are expressed somewhere in a range between those two absolute numbers, giving less definitive results.
The higher the number, the more likely the relationship exists.
Paternity DNA tests are much more accurate when correct testing protocols are followed. Errors do happen when a sample is contaminated or mislabeled, or when a father uses an imposter to hide his paternal identity.
With a paternity test, the key result is whether the alleged father is Excluded or Is Not Excluded as a child’s biological father. When a result is Excluded, this means that the person in question cannot be the father based on test results.
When a test comes back as Is Not Excluded, this means that the person in question is considered the biological father of the child because they do share a biological relationship.
A Probability of Paternity is also included and is scored from 0% to 100%. A 0% result means that the alleged father is not the biological father. A result that approaches 99.99% means that the alleged father is the biological father.
Different brands of DNA tests in ancestry and heritage
There are dozens and dozens of DNA tests on the market for ancestry and heritage. However, five in particular are recognized as leaders for a variety of reasons.
FamilyTree DNA. Founded in 2000 and based in Houston, this company offers autosomal, Y-DNA and mtDNA testing. It has partnered with other companies worldwide to offer service in local languages or specialist research expertise.
When the National Geographic Society launched the Genographic Project in 2005, they selected Family Tree DNA as the testing company for all public participation.
AncestryDNA. Is the database owner of myfamily.com which is the owner of Ancestry.com
It offers an autosomal DNA test and is in three dozen countries worldwide. It offers a Migrations tool that will show where your ancestors were between the years 1750 and 1900.
By defining this timeline, they are often able to better deliver origins results that match up with what you already know about your family history.
MyHeritage. Boasts of more than 100 million users worldwide and almost 10 billion historical records. It supports 42 languages and currently lists 3.3 billion people in family trees.
LivingDNA. Pinpoints specific geographic regions, especially those in the United Kingdom which is broken down into 42 categories. It can be used for biogeographical ancestry analysis with Y-DNA and mtDNA haplogroup reports.
The test cannot currently be used for genetic genealogy since there is no matching database.
23andMe. Provides a variety of tests for ancestry and health information in the United States, UK, Ireland and Canada. An ancestry-only test is available for US $99 from 23andMe’s international site in the following countries:
Albania, Armenia, Australia, Austria, Azerbaijan, Belarus, Belgium, Bosnia and Herzgovina, Bulgaria, Croatia, Cyprus, Czech Republic, Estonia, France, Georgia, Germany, Greece, Hong Kong, Hungary, Iceland, Israel, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Macedonia, Malta, Moldova, Monaco, New Zealand, Northern Mariana Island, Norway, Poland, Portugal, Puerto Rico, Romania, San Marino, Singapore, Slovakia, Slovenia, Spain, Switzerland, Vatican City.
The most accurate DNA test for ancestry
Different genetic testing companies will yield different results. This is because it can only match people to relatives who are in their particular database.
In other words, accuracy will vary, not because of the quality of the test, but the amount of data behind it. This means, if you’re really serious about ancestry and genealogy, you should consider purchasing more than one test to confirm and hone in even more of specific results.
The fact of the matter is that if you stick with one of the mainstream and widely recognized tests, you should get ample feedback and analysis in the vast majority of cases.
Family DNA testing for Asian, Jewish and Native American ancestry
Because the amount of DNA samples collected and analyzed tends to heavily favor people of European ancestry, the accuracy and amount of information that’s available for DNA ancestry and heritage testing is best served for that population.
However, there are other subsets of heritage and ancestry that also have an interest in learning more about their past as well. While not as exact as European testing, there are some encouraging and limiting things to consider.
Jewish Ancestry. First of all, Judaism is a religion and not an attribute definable by a DNA mutation, but it is possible to uncover certain information that may lead to general conclusions. Overall though, Jewish genealogy can be problematic for several reasons.
Some of these include the fact that traditional paper trails are lacking and the Jewish population frequently intermarries.
Surnames also pose a challenge because unrelated paternal lines have adopted the same surnames, or they have been adapted to the country where descendants live today.
Add to this that surnames that pass from the father to the son were not adopted until the late 1700s and you can get an idea of why there are limitations.
Asian Ancestry. The main problem with tracing Asian ancestry through DNA testing is that there are still relatively small sample sizes and imprecise ways to allocate them to specific ancestry.
As more people are being tested, the available data will grow and result in more accurate and precise results, but for now this is a limiting factor.
Native American Ancestry. DNA testing for Native American ancestors is a good place to start your search, but if your goal is to become a registered member of a federally recognized tribe, you will need to provide additional documentation.
For many federally recognized tribes, 1/16 ancestry (6%) is the bare minimum for being accepted as a registered member of the tribe. And even if your DNA is higher than 6%, you could still be denied recognition because the DNA contribution may have come from several tribes.
For this reason, autosomal testing is better for ruling out Native American ancestry than proving it. If you go back four generations, you are only getting about 1/16, or 6%, of your DNA from each.
This means if you had a great-grandparent in a prior generation who had a European spouse, the most Native ancestry you could show would be less than 1%.
Y-DNA and mtDNA tests are better indicators. They will make it easier to spot a distinct haplogroup unique to North America. A haplogroup is a particular set of genetic mutations.
When people migrated from Africa to other parts of the world thousands of years ago, unique DNA mutations occurred. Humans in the Americas were mostly isolated for a long period, meaning that a unique haplogroup developed.
When a test shows a haplogroup that is found primarily in North Americans, it is a strong indicator of Native American ancestry.