Welcome to the second in our series of articles about how to search for unknown family members.
I introduced the series in the article, DNA: In Search of…New Series Launches.
This article addresses the question of “How did this happen?” and introduces the tools we need to answer that question. I’ve combined two articles into one because I really didn’t want to leave you hanging after introducing you to the problem.
We discuss the various kinds of DNA tests, when they are appropriate for your biological sex, and how one can use them to discover information about the person or people you’re seeking.
In other words, we begin at the point of making the discovery that there is something amiss, then review possible glitches. Once we confirm there is someone you need to search for, we discuss how to use genetic testing reasonably and in a planned fashion to solve that mystery.
Please note that I am NOT referring to unexpected ethnicity results in this article. This article refers to your match list and who you do and don’t match on that list. We will discuss ethnicity and how it can help you in a different context in a future article.
Some people have known all their lives that they were adopted, or that they didn’t know the identity of one parent, generally their father.
Other people have made or will make that discovery in a different way. Sometimes, that realization happens when they take an autosomal DNA test and don’t match people they expect to match, either not at all or in a different way.
- You might not match a parent or a sibling.
- You could match only people on your mother’s side, but no known relatives on your father’s side.
- Your parents or siblings have tested, but you don’t match any of them.
- Your immediate family hasn’t tested, but your first and second cousins have tested, and you don’t match any of them.
- You recognize no people, families, or family names on your match list.
- You think you know your genealogy, but nothing on your match list looks familiar.
- If your parents and close relatives haven’t tested, not recognizing families might be explained if your family is part of a community of undertested individuals.
- You might not recognize anyone or surnames if you know absolutely nothing about your family genealogy.
- Sometimes, a sibling is reported as a half-sibling instead of a full sibling, which is an unexpected finding. This means that you only share one parent, not two. I wrote about this in the article Full or Half Siblings. The non-matching parent is generally the father. The question that follows is, which one of you, if not both, weren’t fathered by the man you thought was your biological father?
These discoveries are generally unexpected and unwelcome – a horrible shock followed by some level of disbelief.
I’ve been there.
My half-brother turned out to not be my half-brother, so we weren’t biologically related at all, although that didn’t change how much I loved him one iota.
Later, I did identify his father, but it was too late for them. My brother had passed on by that time.
Ironically, his biological family would have welcomed him with open arms.
If you’re interested, I wrote about our journey in a series of articles:
- Semper Fi, Dave
- Dear Dave: I Found Your Father
- Dear Dave: Meet Your Family
- Dear Dave: You’re Featured in a Book
The Shock of Discovery
It’s difficult discovering that your full sibling isn’t a full sibling or not a sibling at all, but it’s even worse when you discover that one or both of your parents are not your biological parent(s) when you weren’t expecting that. Obviously, sometimes those two shockers accompany each other.
And no, if you don’t match your parents, siblings, first or second cousins, DNA tests can’t be “that” wrong in terms of matching. That’s generally the first question everyone asks.
Yes, we have seen a couple of instances of test mix-ups at the labs, many years ago, among the millions of tests taken. Better quality control procedures were introduced, and a mix-up hasn’t happened in a very long time. However, if you really think that’s a possibility, or you need peace of mind – order another test from the same vendor. If the second test comes back with the same match list as the first test, there is no lab mix-up.
Or, you can order a test from another vendor – something you’re going to need anyway to solve the mystery and for your genealogy. Hint – the two vendors you must test at directly are Ancestry and 23andMe because they don’t accept uploads. If you’re going to order another test, make it one or both of those.
Before deciding you’ve discovered a genetic disconnect, let’s take a deep breath and look at a couple of other possibilities first.
Be Sure the Vial or Transfer Wasn’t Confused
If you’re encountering a situation where you’re not matching relatives that you know have tested, or for some reason, you suspect something isn’t right, the first things that need to be considered are:
- Are you positive that your relative(s) have taken a DNA test? You wouldn’t believe how many times someone has told me that they don’t match their mother/father/sibling and come to find out, their family member hasn’t tested. Did they order a test but never send it in? Did they send it in, but their results arent’ back yet?
- Are you positive that your relative(s) tested at the same company where you did? Many times we discover that they’ve tested, but at a different company. Have your relative show you their results, take a screenshot, or give you their login to confirm you’re at the same vendor.
- Are you missing all of your relatives or just one or two in the same line? If the answer is one or two, they, not you, may have a disconnect, especially if you match other people on the same side of your family.
- Did you and a friend or spouse both swab or spit at the same time? If so, is there any possibility that your and their vials were inadvertently swapped when you put them in envelopes and mailed them?
If there is any doubt, check with that other person and see if they are experiencing the same issue. If you look at their results, you may recognize your own family. I’ve seen this occur at family reunions and at the holidays, where several DNA tests were taken by various family members.
- This last situation is much more common and is caused by confusing files during a download/upload to another vendor. Do you manage multiple kits, and did you inadvertently download the wrong DNA file, or upload the wrong person’s DNA file to a different vendor?
If so, you’re looking at someone else’s results, thinking they are your own. If that person is a cousin, you may be even more confused because you may match some of the same people, just at very different levels. This could make your sibling look like a half-sibling or first cousin, for example.
If there is any possibility of an upload mix-up, or any doubt whatsoever:
- Delete the suspect file at the vendor where you uploaded the DNA file
- Delete the downloaded files from your computer
- Start over by downloading the DNA file again from the original vendor
- Label the downloaded file clearly, and immediately, with the tester’s name and date.
- Upload the new file to the target vendor before you download another person’s DNA file.
Step-by-step upload/download instructions can be found, here.
Not Parent Expected
If you discover that one of two parents is not the expected biological parent, you’ve discovered a genetic disconnect that is known by a number of different terms. Initially, the term NPE was used, but other terms have been added over the years, and they are sometimes used differently, depending on who is speaking.
- NPE – Non-Parental Event, Not Parent Expected
- MPE – Misattributed Paternal/Parental Event or Misattributed Parentage Experience
- Undocumented Adoption – Regardless of how the situation occurred, it was not documented.
Please, please do NOT jump to conclusions and make assumptions about infidelity and duplicity. There can be many reasons for this occurrence, including:
- Agreed upon “open” relationships
- Intentional impregnation when one partner is infertile
- Sperm donor
- Unknown first marriage, with step-father raising a child as his own
- Illegitimate birth of a child before marriage
- Lifestyle choices
In other words, the situation may have been known to the involved parties, even if they did not share that information with you or others. Prior to the last 20 years, no one would ever have considered that this information might ever be revealed. Social norms and judgments were very different a generation or more ago.
I wrote about this in the article, Things That Need To Be said: Adoption, Adultery, Coercion, Rape, and DNA.
Of course, these events could happen in any generation, but the closer to you, in time, the more evident it will be when looking at your matches.
Now that we’ve determined that we have an unknown parent or grandparent, how do we sort this out?
Let’s Start with the Basics
I’m going to begin by explaining the basics of the different kinds of tests, and when each test can be used.
In this series, we will be focused on searching for six individuals, separately – both parents and all four grandparents.
You will be able to use the same techniques for ancestors in more distant generations by following the same instructions and methodologies, just adapting to include more matches to reach further back in time.
We will be taking the search step-by-step in each article.
Four Kinds of DNA
For genealogy, we can work with four kinds of DNA:
- Autosomal DNA
- X DNA
- Y DNA
- Mitochondrial DNA
We can potentially use each of these when searching for unknown ancestors, including parents and grandparents. Each type of DNA has specific characteristics and uses in different situations because it’s inherited differently by the son and daughter, below.
In these examples, everything is from the perspective of the son and daughter.
Y DNA testing is only available to males, because only males have a Y chromosome which is inherited directly from the father, shown by the blue arrow. In other words, the son has the father’s Y chromosome (and generally his surname,) but the daughter does not.
The Y chromosome can provide surnames and very close matches, or reach far back in time, or both. Ideally, Y DNA is used in conjunction with autosomal testing when searching for unknown individuals.
Mitochondrial DNA can be tested by everyone since males and females both receive mitochondrial DNA from their mother, passed to her from her direct maternal line, shown by the pink arrows and the yellow hearts. Both the son and daughter can test for their mother’s mitochondrial DNA.
Both Y DNA and mitochondrial DNA can reach far back in time, but can also be informative of recent connections. Neither are ever mixed with the DNA of the other parent, so the DNA is not diluted over the generations.
Think of Y DNA and mitochondrial DNA as having the ability to provide recent genealogy information and connections, plus a deep dive on just one particular line. Fortunately, when you’re looking for parents, the lines they test are the direct maternal (or matrilineal) line and the direct paternal (or patrilineal) lines.
Both Y DNA and mitochondrial DNA tests are deep, not broad. One line each.
Y DNA and mitochondrial DNA will both be able to tell you if that specific ancestral line is European, African, Native American, Asian, Jewish, and so forth. Additionally, both offer matching at FamilyTreeDNA, information about where other testers’ ancestors are found in the world, and more.
If you want more information about what these tests have to offer, now, I provide a Y DNA Resource page, here, and a Mitochondrial DNA Resource page, here.
Autosomal DNA is the DNA contributed to you on chromosomes 1-22 by your ancestors from across all your ancestral lines in your tree, shown by the green arrow.
Everyone receives half of their autosomal DNA from each parent, with the exception of the X chromosome, which we’ll discuss in a minute.
This means that because the parent’s DNA is cut in half in each generation, the contributions of more distant ancestors’ DNA are reduced over time, with each generational division, until it’s no longer discernable or disappears altogether.
Autosomal DNA is broad across many lines, but not deep.
This figure provided by Dr. Paul Maier at FamilyTreeDNA, in the MyOrigins 3.0 White Paper, illustrates that by the 7th generation, you won’t receive DNA from a few of your ancestors. Some may be contained in segments too small to be reported by DNA testing vendors.
Translated, this means that autosomal DNA matching is most reliable in the closest generations, which is where we are working.
There is no documented occurrence of second cousins who don’t match each other. 90% of third cousins match, and about 50% of fourth cousins. I wrote about that in the article, Why Don’t I Match My Cousin?
The 23rd Chromosome – Sex Determination
Autosomal DNA generally refers to chromosomes 1-22. The 23rd chromosome is the sex selection chromosome.
Males have a Y chromosome contributed by their father, and an X contributed by their mother. The Y chromosome is what makes males, male.
Females have an X chromosome contributed by both their mother and father, which recombines just like chromosomes 1-22, but women have no Y chromosome.
In this graphic, you can see that a male child receives the father’s Y chromosome and the mother’s X. The female child receives an X chromosome from both parents.
Only FamilyTreeDNA and 23andMe report X chromosome results by including them with their autosomal DNA test.
Let’s take a look at how the X chromosome works in a little more detail.
X Chromosome DNA is another type of autosomal DNA, meaning it can be inherited from both parents in some circumstances. However, the X chromosome has a different inheritance path which means we analyze it differently for genealogy.
The father gives an X or a Y chromosome to his offspring, but not both.
If the child inherits the Y chromosome from the father, the child becomes a male. If the child inherits the X chromosome from the father, the child becomes a female.
Men only receive an X chromosome from their mother since they receive a Y chromosome from their father. Men can inherit a mixture of their mother’s X chromosomes that were contributed to their mother from both her mother (peach) and father (green.) Conversely, men can inherit their maternal grandmother’s or maternal grandfather’s X chromosome intact.
In this example, the mother and father have three sons. None of the sons can inherit an X chromosome from their father, whose X chromosome is shown in yellow. The father gives the sons his Y chromosome, not shown here, instead of an X, which is how they become males. Males only inherit their X chromosome from their mother.
The mother inherited one copy of her X chromosome from her father, shown in green, and one copy from her mother, shown in peach.
- The first son inherited his maternal grandfather’s green X chromosome, intact, from his mother, and none of his maternal grandmother’s peach X chromosome.
- The second son inherited a portion of his maternal grandmother’s peach X chromosome and a portion of his maternal grandfather’s green X chromosome. I’ve shown the portions as half, but the division could vary.
- The third son inherited his maternal grandmother’s peach X chromosome, intact, and none of his maternal grandfather’s green X chromosome.
This means if you match a man on his X chromosome, assuming it’s a valid match and not identical by chance, that match MUST come from his mother’s line.
In a future article, I’ll provide some X-specific fan charts and tips to help you easily discern potential X inheritance paths.
Women inherit an X chromosome from both their mother and father. They inherit their father’s X chromosome intact that he received from his mother, because he only has one X to give his daughter. Therefore, daughters inherit their paternal grandmother’s X chromosome from their father, because he passes on exactly what he received from his mother.
In this graphic, the father and mother have three daughters. You can see that each daughter receives the father’s yellow X chromosome that he inherited from his mother.
He doesn’t have a second copy of an X chromosome to mix with his mother’s.
Women inherit their mother’s X chromosome in the same fashion that men do. You can see in our example that:
- The first daughter inherited her father’s yellow X chromosome, plus her maternal grandmother’s peach X chromosome, intact, and none of her maternal grandfather’s green X chromosome.
- The second daughter inherited her father’s yellow X chromosome, plus part of her maternal grandfather’s green X chromosome and part of her maternal grandmother’s peach X chromosome from her mother. The portions of the mother’s pink and green chromosomes inherited by the daughter can vary widely.
- The third daughter inherited her father’s yellow X chromosome, plus her maternal grandfather’s green X chromosome, intact, which is his mother’s X chromosome, of course. This daughter inherited none of her maternal grandmother’s peach X chromosome.
Women inherit two X chromosomes, one from each parent, while men only inherit one X, contributed from their mother. This means that X matches have different inheritance paths for women and men.
Because the X inheritance path involves the mother, many people confuse mitochondrial DNA inheritance with X inheritance. I wrote about that in the article, X Matching and Mitochondrial DNA is NOT the Same Thing.
Testing Strategies and Vendor Strengths
In the next article, we will be discussing detailed testing strategies based on multiple factors:
- Who you are searching for in your tree
- Who, other than you, is available to test
- Sex of the tester(s)
- Vendor strengths and unique offerings
- Urgency, or not
- Using combinations of vendor results and why you want to
Getting lucky may be what you hope for, but it’s not a strategy.😊
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Thank you for this. I always knew I was adopted at birth. I was born in 1953. I was lucky and found my adoption papers in the safe my parents had in 2000. They named my bio parents, which was later confirmed by DNA matches with half sibs and many cousins of all degrees. My issue is finding a second great-grandma. Unnamed, no marriage record, three children. All other trees name second wife as mother to the three but not possible. Way too young.
Thanks for the interesting article. I don’t understand this:
“This means if you match a man on his X chromosome, assuming it’s a valid match and not identical by chance, that match MUST come from his mother’s line”
If a man has a DNA match with a man, is it possible to determine that this match is on his female line? The article says that X is not transmitted to a man from his father. So how can I find out that this is a match on the female line of another man?
Is it enough for X to be a match for another man, or does it have to be a match for both? Which of these two men has X in the FTDNA? Only the man on the other side, or both men?
Sorry for my bad english, I’m translating with google translate.
For two matching men, an X match comes from both of their Mother’s lines.
Thanks for the answer. That is, if at least one of the men has a match on the father’s line, then a match between them on X is impossible at all. This is very good because it excludes all lines with X sections, reducing searches and making them easier.
The key in this sentence is the coincidence of the X of BOTH men.
I do have all the names of my grandparents. However, my father left when I was about 2 years old. He returned to his home country, Germany. When I first attempted to fill out my family tree, I found a publicly available, digitized WWI record for his father. Evidently, the guy was illegitimate, with only his mother and her place of residence identified. (Not one of those situations in Germany where a couple concieved first then after a year plus married.) It’s very unfortunate that my great grandmother’s surname was Schmidt, from cradle to grave! I probably can only figure out the identity of his father via DNA matches. I have one possibly relevant and very new match at MH. He’s my fourth highest match there. An 80 year old guy ER who left Germany post WWII for Canada. We share 57.1 cM… which I guess is a bit more useful, considering it’s probably involving a half relationship… going back 4 generations at least in my case. (It could also be a 1x or 2x removed scenario b/w ER and me.) ER’s daughter and I have had quite a few exchanges… but like always… there is a bit of chill if a possible NPE is part of the story. (My third highest match at MH is an Australian guy. I am 99% convinced I solved that NPE match… but this predominantly Anglo-Irish, well-educated guy is not buying it… that we are half 2nd cousins via my known great grandfather, EH,… who was a young German Imperial naval officer, apparently sowing his seeds, on a well-documented voyage, around the Cape of Good Hope, with extensive time in Australian ports… in the late 1890’s. I even have this Uropa’s general Y chromosome… My second highest MH match, J-E H, is the grandson of a younger brother of EH. So J-EH is my full 2nd cousin, once removed. We share 91 cM. My top MH match is my biological daughter, whom I raised. : ) – Genealogy… challenging, intriguing, and for some – quite unsettling. I have another Aussie top match… so I think my great grandfather had “fun” in more than one port. None of those Aussie folks… all at the top of my Ancestry list… want to know. : ( (Final thing… I have a half sister in Germany, via my deceased father. He told me about her. I don’t know if she knows about me. I guess we have one identical X chromosome from our respective pair of X chromosomes.) I will follow your series carefully. (I’ve come across several matches who are adoptees. Too distant for me to help them much, sadly.)
You’ve already completed a lot of work.
This article shed some light on a family mental health issue which I have spent some time looking at. It is obviously along my mother’s line, but very few relevant cousins have tested their DNA. However, thanks to you, I now have an explanation of the possible inheritance pathways.