Overcoming Brick Walls in Your Family Tree with a Genealogy DNA Test

February 22, 2019  - by 

Today, many people are turning to DNA testing to overcome brick walls in their family history research. When you are unable to find information to go back any further in your family tree, DNA testing might help you break through these research barriers.

To get through a brick wall, successful genealogists often start by using traditional research methods and tried and true techniques. A genealogy DNA test can work alongside these methods and help break through a brick wall when nothing else can.

Three Types of DNA Testing You Might Use to Overcome Brick Walls

There are several DNA companies that provide opportunities to find relatives in what is generally called a “DNA match list.” DNA cousin matches are people whose DNA significantly matches your own. But with many types of DNA tests, how do you know which one to use? Below is a quick summary of three types of DNA testing that can help the most with brick walls.

  • An Autosomal DNA Test—This DNA test can be taken by males or females and will typically give you DNA matches within about 5 to 6 generations on both your mother and father’s sides of the family.
  • The YDNA Test—This DNA test can be taken only by a male, as it is used to track the Y chromosome passed from father to son over the generations. It extends back many generations. The YDNA test can provide relative matches and a paternal haplogroup. If a father’s family line is in question, this DNA test may help break down that brick wall.
  • The mtDNA Test—This DNA test can be taken by males or females, but it looks only at the genetic markers of your mother’s maternal line. It too extends back many generations. The mtDNA test will provide a maternal haplogroup and DNA matches for the maternal line. If your brick wall involves your mother’s maternal family line, this DNA test may be helpful (although an mtDNA test will naturally have a higher margin for error in the maternal line than a YDNA has in the paternal line).

A woman performs a dna test.

Strategies for Overcoming Brick Walls with DNA

After you’ve taken a DNA test, various strategies can help you break through your brick wall problem. Here are some common problems that DNA can help with and strategies for tackling these brick walls with your DNA test results.

Using DNA to Find an Unknown Parent or Grandparent

To find an unknown parent or grandparent, start by sorting your DNA matches into groups. Many companies help you do this sorting by using a shared or “in common with” feature to show you matches that share DNA with each other. When a whole group has matching DNA, it may mean they all share a common ancestor.

Compare trees with some of these matches to see which groups are connected to your known parents or grandparents, and set these aside. With these set aside, you can focus on matches that might lead you to your unknown relative. Compare trees with these matches, and try to find an ancestor who appears in more than one of the trees. This approach provides a starting point for traditional research, as this common ancestor is possibly related to you and your unknown relative.

As you research the descendants of this common ancestor, look for dates and places that match the information you know about yourself and your unknown relative. Confirm your relationship by asking other living descendants to take a DNA test.

a man researches his family on a laptop.

Using DNA to Find New Avenues for Research

If your research hits a brick wall due to immigration or migration, name changes, or missing records, DNA may suggest clues that can lead you to new relatives, surnames, or locations. To identify these clues, you’ll need to use information about your brick-wall ancestor (the ancestor whose family line ends or who you’re trying to find more information about).

First, identify other descendants of your brick-wall ancestor who have also taken a DNA test (or ask other descendants to take a DNA test). Use the shared or “in common with” feature provided by your DNA testing company to identify other DNA matches connected to the same brick-wall ancestor. Review those matches and their trees. Look for people, surnames, or locations that match the information you already know about your brick-wall ancestor. Next, use records to research these relatives and try to connect them to your brick-wall ancestor.

Using DNA to Confirm a Relationship

If records were burned or are missing or were never created, you can break brick walls by first hypothesizing and then using DNA to confirm a relationship. Start by researching your brick-wall ancestor and identifying possible relatives. Then locate and test living descendants of both your brick-wall ancestor and the possible relatives of this ancestor. Compare the DNA of the descendants of the brick-wall ancestor with the DNA of the descendants of the proposed relatives. If the DNA matches at an expected rate, the relationship probably existed.

Using DNA to Do Collaborative Research

Once you have identified DNA matches that may be related to your brick-wall ancestor, contact these matches to discover what they know about their family lines, especially if they have not uploaded a tree to the DNA testing site.

If your brick-wall ancestor is more recent, a DNA match may have living memory of the person or the person’s descendants who can help you track down relevant records and vital information. They may also have a family tree or other information that can help.

If your DNA match does not include a family tree or has limited information but you both want to learn more about your ancestors, you may want to work on the problem together. A family history site that allows you to upload and share family tree data can be a good way to learn from and collaborate with DNA matches. FamilySearch.org offers a shared family tree for free.

Getting Help

Solving brick walls with DNA is not a simple or easy process, but many places offer DNA help. Consider asking an expert for help in setting up a strategy for you. Family history and DNA experts can also advise if DNA testing can help with your particular brick wall and can even help you with the research itself.

a man helps a couple with their family tree.

How Miles and Angela Overcame a Brick Wall with DNA Testing

For over 20 years, Miles and Angela had searched for the parents of Angela’s ancestor Willie Mae Harris (1864–1909). Willie Mae Harris had appeared in very few records, leaving Miles and Angela with few clues of her parentage.

Traditional research led Miles and Angela to find living descendants of Willie Mae and collect DNA samples from many of them. Using DNA match lists from these known descendants, they were able to find a previously unknown DNA cousin match. This newly discovered cousin had uploaded a family tree that included ancestors with the surname of Harris. Angela and Miles quickly sent an email to the cousin via the DNA testing website to compare their Harris family lines. It was determined their common ancestral link was William E. Harris and Fredonia Aust Harris. With this couple finally identified, further research led to the confirmation that William and Fredonia were the parents of Willie Mae Harris.

In addition to breaking through this 20-year brick wall, Angela found additional living cousins, one of whom sent pictures of William and Fredonia Harris, Willie Mae’s parents. DNA testing was the key to solving this family research problem and extended another generation on their family tree.

Have you had family history success using DNA testing? We would love to hear your story in the comments below.

More about DNA Testing

Compare options for DNA testing and find answers to DNA questions on FamilySearch.org.



Amie Tennant

Amie Bowser Tennant is a genealogy researcher, writer and presenter.She writes blog articles and other content for many top companies and societies in the genealogy field. Her most treasured experience is working as a consultant for family history. Amie lives with her husband and three children in Ohio, surrounded by many of her extended family.

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  1. Could you tell me if my Ancestry DNA test results can be somehow linked into my familysearch.org tree? How can my Ancestry DNA be used in my familysearch.org tree?

  2. Just discovered my paternal grandfather wasn’t my biological grandfather. Had matches I thought were connected to being my paternal great grandmother’s folks who I didn’t know about. When known 2nd cousins matched my dad’s siblings offspring but not me I started looking closer at cM’s and DNApainter.com I already had match lists by groups and in Ancestry could look at shared matches. I stared all my shared matches and they were pretty much in my suspected family group. I already had worked out most recent common ancestor trying to make something fit in the 2nd great grandparents range. What was confusing was the MRCA family was in the same area as first great grandmother in AR in 1860-1880’s and also in Tarrant Texas ( same census) as where my dad’s family was. Pretty sure I have the top two candidates, brothers but could be somebody else. I have been in contact with the grandson of one of the suspected brothers. I contacted FTDNA about the Y-DNA test and they suggested I get ahold of a DNA Genealogy professional. Pretty sure I’ve done about everything I can without the Y-DNA test.
    I’ve uploaded my dna test to GedMatch/Genesis but no closer matches.

  3. Can you use DNA tests of two living cousins to see if they actually shared the same grandparents? My cousin and I just found out from a very distant relative doing geneology research that my cousin’s father (my uncle) may have had a different father (so we would have the same grandmother but different grandfathers). This claim is unconfirmed but intriguing. Would a DNA test be able to tell us if we share 2 grandparents or just one?

    1. I found this out in a round about way. See my post above. The cM values will be less if half cousin vs full cousins. The short answer is yes you can. I matched supposed 1 cousins 1 & 2x removed thru my dads mother. My supposed 2 cousin matched them thru my dads non biological father who I assumed was my biological grandfather. Only after looking at cM and color coding matches into groups did the light come on for me. Larry’s videos really pointed me in the right direction. Look at his cM and triangulation videos but since you already know who you are testing with it’s mostly just if your are first cousins or half first cousins.. If you are half first cousins then color coding groups and triangulation will help finding your grandfathers line. I just sent in my Ftdna Y-111 test to see if my hypothesis is on track or not. DNApainter.com cM tool (free online) is a good place to start and Larry uses it in his video.
      good luck
      Mike Swift

  4. I never knew that YDNA test can only be taken by a male. My dad has been wanting to try DNA testing since he’s been curious about his family line. Speaking of such, I wonder if there’s a next-generation dana sequencing available.

    1. I just got my YDna test results back today. There are a few matches with the family name I’m sure I’m related to. However I have several Pittman matches that are very distant in my Ancestry autosomal matches. I have a lot of investigating to do and messages to send. I’ve sent one off this morning who I think is connected as his middle name is the last name of a gentleman I’m in contact with and his last name is the family name I’m sure I’m connected to. I have found my most recent common ancestor couple and the most associated families matched are on the wife’s side, Martin. The husband side Wall shows up a few places on YDna test. Martin does not. I know that’s not much help. I am ahead of where I was a month ago when I figured out my paternal grandfather is not my biological grandfather.

  5. Hi, after doing a DNA test , I found out my Mothers known father was not her biological father, I have been trying through my DNA to find out who he is . I have used clustering but have know idea what I’m doing.. help.