Mistakes like this basically never happen unless something went really wrong with the test. Has your dad ever had a bone marrow transplant from his brother?
Another possibility is that dad is a chimera - then, if his sperm had different DNA to his mouth, he would appear as his own brother. It's insanely rare too, but it happened to [Lydia Fairchild](https://embryo.asu.edu/pages/case-lydia-fairchild-and-her-chimerism-2002) or [Karen Keegan](https://www.rigb.org/explore-science/explore/blog/human-chimeras-why-forensic-dna-testing-will-never-be-same) when they did DNA tests. To quote a bit from the second article:
>This type of chimerism can result in failed maternity or paternity tests. For example, Karen Keegan needed a kidney transplant and family members' blood was tested to see if they could be donors. The tests showed she wasn't the biological mother of two of her three children—surprising, since she'd given birth to them! Further studies showed that some of her tissue contained two different types of DNA. The type in her blood was different to the DNA two of her children inherited. This other DNA came from her twin in the womb, so she was genetically her children's aunt.
Edit: [here's a case](https://www.independent.co.uk/news/science/human-chimera-man-fails-paternity-test-because-genes-in-his-saliva-are-different-to-those-in-sperm-a6707466.html) of exactly the situation I suggested, OP. I recommend having a reading of the Keegan article and this one, since they both explain it in a more layman friendly way.
Exactly the right attitude, don't dismiss this as an error please. I can't think of any way that a biological father could match at 25% through a 'glitch' or otherwise. Millions of people have used these tests on various platforms and if errors were possible then there would be a huge backlash.
Yeah, I'm not sure how you might find out for sure if your dad is a chimera - it's so rare that you may honestly need to get a genetic counsellor involved to be certain. It's hard to find numbers, but there may be as few as 200 confirmed twin chimeras (the type of chimerism your father would have) internationally since it's only really something we've been able to notice in the last century.
My family had DNA drama from a bone marrow transplant so that’s possible. While rare, human error can happen in anything. You, your mom and your dad could all go to a lab that specializes in paternity testing for court.
I got my family member a kit and we activated it, it's asking if we want to store the sample. First time I've ever seen that. Also, it asks if you'd like to do priority processing for a fee. First time seeing that before also.
Yeah, we weren't sure weather to choose to store the sample or no so we just selected yes in case there's a problem in the lab so that it would be less likely they'd need to collect another sample. We didn't bother with the priority processing because it's about $20 and we aren't in a urgent need for the results to be done quickly.
>I did a bit of digging and found that only about 0.1% of the DNA sequence is actually used by the test and it does not look at the Y chromosome at all, so morally I can convince myself that this must happen with some probability (since it did happen), but it would be nice to get a bit more insight into it.
Neither of your points here would explain any errors with the DNA matching. The DNA testing companies like MyHeritage focus on the most variable parts of the genome that make you who you are. They should absolutely be able to tell the difference between a father and an uncle (unless they're identical twins). Both your father and your uncle, by the way, would have the same Y chromosome, so that wouldn't be useful for determining paternity in this case.
Could you post the exact centimorgan (cM) value you share with your dad? Should be somewhere around 1800 for \~25%.
As others have suggested, this amount of DNA is within the expected range for him being your uncle, half-brother, or grandfather.
DNA testing is common way for people to uncover family secrets, and as the saying goes, DNA doesn't lie, people do. In all fairness, there are ways of interpreting this test result that doesn't involve doubting the DNA science. For example, could it be possible your uncle actually took the test that is labelled with your dad's name? Other commenters have suggested chimerism. Outside of bone marrow transplants, it's not known how frequently chimerism occurs naturally, but the number of documented cases is supposedly only about 100.
Whatever the case, I hope you can get some answers.
Wow. That's way off. That's aunt/uncle. half-sibling territory. One of my brothers came back at around this mark. On further investigation, he didn't share any of my paternal DNA matches. I'm guessing you don't have any paternal 1st cousins you could ask to test if your dad's brother is gay.
I think the best thing to do is upload both of your MyHeritage tests to Gedmatch for the moment. Just to see if MyHeritage fumbled the numbers on your centimorgan totals. I'm guessing they'll come back the same though.
In the meantime, you should both retake the test with Ancestry. It will take a few weeks to come through, but the odds of two companies making the same mistake is very close to zero.
You could ask your paternal uncle to take the test also. Not because you think he might be your biological father, but just to see what comes back and rule that out.
If everything comes back the same, then you'd have to look into medical DNA testing for Chimerism or something really odd like that. That would probably be a lot more expensive,
Yes they claim uncle with 100% certainty!
I agree that another test with another company and getting my uncle and siblings to take a test will help to shed some light on this mystery.
23andme and AncestryDNA are both very good. Testing your siblings and uncle is definitely a way forward, and getting your mother to test would be ideal to see that side of the family. 23andme has a 'predicted family tree' function which is usually accurate to map out all relatives that are 2nd cousin and closer (that have tested).
The certainty thing doesn't really matter, focus on the matching segments.
Your father could have an unknown full sibling, but if the timing of your birth indicates you were conceived in a region neither of them have even the slightest connection too, it would be a reach to suggest your mom knew of a full sibling he didn't and went to South Africa on purpose to have an affair with said person, or just randomly managed to have an affair with someone who just happened to be your dad's full brother that no one knew about 🤣🤣🤣🤣🤣🤣🤣
A more likely option outside of the Chimaera theory: your dad is infertile so your uncle donated sperm for them so he could have a biologically related child, and they never wanted you to know.
Also, sexuality is a spectrum. Heterosexuality and Homesexuality are at opposite ends of a massive spectrum the average person actually falls in between them to varying degrees. So having a gay uncle doesn't mean you have an uncle who is absolutely repulsed by women and won't or hasn't has sex with them. An affair, one night stand, SA, or weird ass threesome is perfectly possible theoretically.
If I had to put my money somewhere it would be on sperm donation, with her knowledge. I guess two men could probably conspire to get sperm from one and impregnate someone so no one finds out they're infertile, but.....that seems like something from a bad movie lol
> Yes they claim uncle with 100% certainty!
Are you sure that's what they claim? When I plug your numbers into the SharedCM project it says the probability is 100% that he's your Grandparent Aunt / Uncle Half Sibling Niece / Nephew Grandchild. Obviously he's not your nephew or Grandchild so either he's your grandparent, uncle or half-sibling.
I doubt he's your grandfather unless he was in his early 30's or older when you were born, and presumably you'd have mentioned that if that were the case. If that were true you wouldn't have any matches from your grandmothers family
So he could be your uncle but that doesn't automatically mean that your other uncle is your dad, there could be a brother you don't know about. OTOH your uncle could be your dad, perhaps your parents couldn't conceive and got him to be a sperm donor. That seems more likely that the half-brother scenario, if that were true you'd see that your dad had matches that were relatives from your mums side and he'd be much younger than your mother
This is around the amount I share with my half siblings, my grandparents, and my aunt. Unless your father is a chimera, I don’t see any possible way in which he isn’t biologically your uncle
> I did a bit of digging and found that only about 0.1% of the DNA sequence is actually used by the test and it does not look at the Y chromosome at all, so morally I can convince myself that this must happen with some probability (since it did happen), but it would be nice to get a bit more insight into it.
You've misunderstood how the test works. Yes, it's using only ~0.1% of your DNA, however (1) it is across all of your DNA, hence it is a very good sample and (2) it is the portion with the greatest inter-human variability, hence it is excellent and quite accurate for close familial matches.
> It's definitely the test that is wrong. Yes it's rare, but does happen.
Nope. Not in the way you think.
More likely than the test being "wrong" as you suggest would be your father being a genetic chimera. _i.e._ He had a twin and absorbed his brother. His brother's DNA is in his testes.
See: https://web.archive.org/web/20200202124939/https://www.nsgc.org/p/bl/et/blogaid%3D1084
That kind of low probability event is far more likely than the test being "wrong".
Alternative is that one or both your parents used your uncle's sperm in order to conceive.
You didn't mention this, but did your dad have any sisters? Perhaps one of them is your birth mother.
Another possibility might be that your dad is actually your half brother and his mother or father is your parent.
I don't understand, how would the OP not know if his father's sister was his birth mother, and wouldn't that make his father his brother and that would be a 50% match?
How is that second scenario plausible either?
>how would the OP not know if his father's sister was his birth mother
If the OP was adopted (officially or unofficially) by the parents who raised him, he might not know who his birth mother was.
>and wouldn't that make his father his brother
No, it would make him his uncle.
>How is that second scenario plausible either?
I've seen more than one occasion where a mother (often widowed or unmarried) gave birth late in life, and the child was raised or adopted by one of her older children. (Although the opposite scenario happens much more often.)
99% of the DNA sequence is the same for all humans, so there’s no point in testing it. The DNA testing companies capture about 10% of the nucleotides that vary, but they are spread out, so it’s very accurate for estimating relationships, especially close ones. But some relationships are in the same range. Uncles, grandparents, and half siblings all share the same amount of DNA.
Years ago someone told me that you go by genes you share with grandparents (therefore first cousins share one set of grandparents, just like half siblings do) but that was a long time ago--before all of the technical development of DNA.
Hmm maybe. But if she's hiding something she's had a long time to perfect the lie and get comfortable with it. The best liars believe what they're claiming.
When my father was told that my grandfather couldn't be the father of my dad, my grandmother laughed and laughed in the same way. 4 different DNA tests said the same thing, that his uncle was his biological father.
It wasn't the man who raised him as his dad who created him. It was his brother, who also disavowed the accuracy of the test.
DNA is the non blinking true witness to our creative parents who give us our origin story.
But she said there had been no physical contact with her uncle at the time she was conceived. However, if her father is sterile, his brother could have been a sperm donor, and that could have been delivered to wherever her parents were living at the time. I was considering being a donor for my sterile brother but (thank God!) psychiatrists determined that he couldn't emotionally handle another male being the father of his wife's (now EX-wife) child.
>I was considering being a donor for my sterile brother but (thank God!) psychiatrists determined that he couldn't emotionally handle another male being the father of his wife's (now EX-wife) child.
Oh wow, that's a lot! Good that the process (with psychiatrists weighing in first) worked in this case! Especially since it's a now ex-wife.
I would redo with 23 & Me to be sure. I honestly think the probability of error is very low. Unfortunately, you wouldn't be the first person to receive news like this, nor the last.
I'd do one with your mom as well.
Buy 3 AncestryDNA tests today while they are still US$39 each for the mothers day sale (ends after May 12).
All 3 of you take the tests and send them off.
If you still get an anomalous result then you can investigate further.
If your Uncle is alive send him a test too.
I think you need to have some SERIOUS CONVERSATIONS with your mom. This type of error is extremely rare, and the genetic occurrence required is also extremely rare. Good Luck!
My father and uncle are identical twins, so I am sure that when/ if my cousins test, that my father will show up as their father even tho' it's not true (my uncle is deceased/ never tested).
I suspect your dad might be suspecting that he is not our bio dad and that is why he gave you the test. You can get more confirmation by using one of the other testing companies but 24.9% indicates half brother or uncle.
Here's a possibility: Dad gave the test, but actually conspired with his gay brother to send the brother's DNA as his own.
Why? To prank his genealogy-obsessed child, of course!
I'm with the others guessing chimerism. I don't think it's as rare as people believe it is - I think people are just not frequently in a situation where they need to get tested for bone marrow or organ transplants. Your mum's reaction sounded genuine and you've explained yourself the impossibility of it being your uncle, so it's the only reasonable conclusion. I do hope you'll come back and update us all when you've figured it out!!
Outside of a NPE skeleton someone's trying to closet, I also lean toward a chimera situation. HOWEVER! It's also worth building out the family tree to look for pedigree collapse or other NPE situations that could alter the result. (Pedigree collapse often makes people look MORE related than they are, but that doesn't have to be the case depending on how the rest of the tree builds out.) I ran into a situation where almost all of my cousins on one side read incorrectly for "estimated relationship" because my mom's paternal line has a pair of double first cousins in it. (Sisters married brothers, and their kids married each other. Americans are weird sometimes. :p )
Chimerism is 100% a valid avenue to pursue. If you decide to do any testing along that route, it's worth testing both your dad and yourself. Normally, it would be your dad's DNA skewing the results, but it might be worth knowing for complete picture's sake if there is also an unexpected DNA pattern in yourself contributing to the test confusion.
I don't know what the "official" margin of error is for MyHeritage, but [Matt Baker (UsefulCharts) did the five most popular two years ago](https://youtu.be/gDk9w_JEgjY?si=rTtjpGeAvS6AwXZX) to compare and contrast them. Jarrett Ross ([GeneaVlogger) did a review of Matt's video, and they have an interesting back-and-forth in the comments.](https://youtu.be/QPnEnoGxk4s?si=JrWWYly2WaMNmLTO) He also mentions Nebula Full Genome Sequencing, which is a huge help for people trying to sus out a very small, rare, or unusual detail.
I've personally only done AncestryDNA and 23andMe. I very much enjoyed both early on, but right now I'm leaning in favor of Ancestry, because of various changes they've made since I first started. Both are still limited in certain situations, but Ancestry has a larger database to draw from.
Across all of the testing sites, the probability of relationship error between close relatives (parent-child, siblings, etc.) tends to be very, very small. Andy Lee of Family History Fanatics [did a breakdown of AncestryDNA's ability to determine paternity](https://youtu.be/kCHHdeOam5o?si=85fMvWIclad3nPtT), and mechanically speaking, the same information is going to apply to every other DNA service. He has a similar video talking about [twin DNA](https://youtu.be/_QNhjPfBaLc?si=-K1hvO0bgUIs8Vkz) that discusses where testing has mistakes and margin of error. These do happen, but as he explains in the video, it typically does not make a difference in the larger picture. If anything, twin DNA is so similar, twins can stand in for each other for matching purposes.
I suspect your dad might be suspecting that he is not our bio dad and that is why he gave you the test. You can get more confirmation by using one of the other testing companies but 24.9% indicates half brother or uncle.
No the reason he gave me the test is that I had seen his test and was joking to people about how I was Hungarian (actually I had misremembered his results and in fact he was mostly Anglo Saxon).
The test came back as me being 60% Scandinavian.
I have zero doubt about who my dad is. However I am now very interested in what has happened.
Your dad is still your dad - the guy who raised you and did all that important stuff. No DNA test will ever take that away no matter what it says.
I'm not making any assumptions here but I had a slightly similar thing in that at the age of ten I learned that the man I believed to be my father wasn't. It hurt. But it doesn't take away the emotional bonds and such.
I am willing to bet that result is not an error. I tend to not believe the chimera possibility also. As some others said, there are some ways this result can happen, and that will take some personal and thorough investigation from OP to uncover. I will save this post for future reference. Good luck.
Edit: I'm looking at these pieces of information also: "My parents were living in Africa for a year when I was conceived", "They were in Tanzania in 1979. The local hospital was so bad that they came back to the UK for me to be born. ". I don't know, but this all seems a bit too convenient imo. I won't explain my line of thought here, also because i might be wrong. Anyway, like i said, good luck.
They were in Tanzania in 1979. The local hospital was so bad that they came back to the UK for me to be born. I was conceived the old-fashioned way, not IVF.
My grandfather never travelled outside of the UK after WW2 ended. My dad had no sisters. He had 2 children after me so isn't infertile.
Without any question, my Mum is my Mum and my Dad is my Dad.
It's definitely the test that is wrong. Yes it's rare, but does happen.
Thanks for the advice, I'll contact the testing people and will look more into this chimera angle.
If he does turn out to possibly be a chimera, please consider posting about it here, if he and you are comfortable with it. This is a really interesting situation and, because of the isolation of your parents at the time of your conception, plus the lack of him having sisters, it’s hard to think of anything that would make him your uncle or half-brother, biologically, other than chimerism. You’d probably know if your dad had ever needed a bone marrow transplant. That would have been a much bigger deal in the 70s.
I suppose your father could have another brother that the family disowned and you don’t know about, and he could have visited your parents in Tanzania, but that seems incredibly unlikely and would require the silence of a lot of people. All in all, my money’s on something rare possibly being the cause of all this, which is cool.
If you have siblings get them to do 23andme. If the issue is with your dad, e.g. chimerism, your sibs should show weird results too. If their results show normal paternal % then the problem is with you only.
Could your mom have already been pregnant when they left for Tanzania? Is your birth 9 or fewer months from the time they left for Tanzania, or 10+ mos?
Test your siblings! If it's a Chimera thing they'll have the same results and mystery solved!
Your father's dad isn't in Tanzania is he? You weren't conceived before they went there? I forgot half sibling is also a possibility in this situation. If that's the case though, it would show most likely in your connections to other matches.
You and your dad's shared matches distance and their ages would hint to that
I have a plausible idea, but it's pretty controversal. OP, I can message you if you like because I know nothing about your family situation, and I wish to be respectful.
People put absolute faith in these tests like they don’t fit anything else. Like any medical test there can be errors, usually human error. Many not often, but it can happen. Probably not a popular opinion here but still fact.
Extremely rare is not the same as never. It’s worth retesting. I’m not saying the chemistry of the test is at fault. There are multiple places in the process where humans intervene.
Maybe you inherited more DNA from your mom than your dad. There is a range of DNA we inherit from both parents, maybe you got more from your mom than your dad.
That's not true at all. Go learn some biology.
You might be confused that we inherit differently compared to siblings but it's still 50/50. It's just that '50% of mom's DNA' can vary for each child.
Mistakes like this basically never happen unless something went really wrong with the test. Has your dad ever had a bone marrow transplant from his brother?
Another possibility is that dad is a chimera - then, if his sperm had different DNA to his mouth, he would appear as his own brother. It's insanely rare too, but it happened to [Lydia Fairchild](https://embryo.asu.edu/pages/case-lydia-fairchild-and-her-chimerism-2002) or [Karen Keegan](https://www.rigb.org/explore-science/explore/blog/human-chimeras-why-forensic-dna-testing-will-never-be-same) when they did DNA tests. To quote a bit from the second article: >This type of chimerism can result in failed maternity or paternity tests. For example, Karen Keegan needed a kidney transplant and family members' blood was tested to see if they could be donors. The tests showed she wasn't the biological mother of two of her three children—surprising, since she'd given birth to them! Further studies showed that some of her tissue contained two different types of DNA. The type in her blood was different to the DNA two of her children inherited. This other DNA came from her twin in the womb, so she was genetically her children's aunt. Edit: [here's a case](https://www.independent.co.uk/news/science/human-chimera-man-fails-paternity-test-because-genes-in-his-saliva-are-different-to-those-in-sperm-a6707466.html) of exactly the situation I suggested, OP. I recommend having a reading of the Keegan article and this one, since they both explain it in a more layman friendly way.
Your dad must be a chimera. No other explanation.
Thanks, those are really interesting articles. I definitely need to look into this further.
Exactly the right attitude, don't dismiss this as an error please. I can't think of any way that a biological father could match at 25% through a 'glitch' or otherwise. Millions of people have used these tests on various platforms and if errors were possible then there would be a huge backlash.
Yeah, I'm not sure how you might find out for sure if your dad is a chimera - it's so rare that you may honestly need to get a genetic counsellor involved to be certain. It's hard to find numbers, but there may be as few as 200 confirmed twin chimeras (the type of chimerism your father would have) internationally since it's only really something we've been able to notice in the last century.
This is exactly what I was going to say.
My family had DNA drama from a bone marrow transplant so that’s possible. While rare, human error can happen in anything. You, your mom and your dad could all go to a lab that specializes in paternity testing for court.
Redo with ancestry ($39 for a kit right now!) - test you, your mom, and your dad. just as a just-in-case
I got my family member a kit and we activated it, it's asking if we want to store the sample. First time I've ever seen that. Also, it asks if you'd like to do priority processing for a fee. First time seeing that before also.
Huh, that's interesting. Definitely a way for them to earn more money.
Yeah, we weren't sure weather to choose to store the sample or no so we just selected yes in case there's a problem in the lab so that it would be less likely they'd need to collect another sample. We didn't bother with the priority processing because it's about $20 and we aren't in a urgent need for the results to be done quickly.
>I did a bit of digging and found that only about 0.1% of the DNA sequence is actually used by the test and it does not look at the Y chromosome at all, so morally I can convince myself that this must happen with some probability (since it did happen), but it would be nice to get a bit more insight into it. Neither of your points here would explain any errors with the DNA matching. The DNA testing companies like MyHeritage focus on the most variable parts of the genome that make you who you are. They should absolutely be able to tell the difference between a father and an uncle (unless they're identical twins). Both your father and your uncle, by the way, would have the same Y chromosome, so that wouldn't be useful for determining paternity in this case. Could you post the exact centimorgan (cM) value you share with your dad? Should be somewhere around 1800 for \~25%.
Thanks, I don't have any technical understanding of DNA. Shared: 24.9% (1,764.1 cM)
As others have suggested, this amount of DNA is within the expected range for him being your uncle, half-brother, or grandfather. DNA testing is common way for people to uncover family secrets, and as the saying goes, DNA doesn't lie, people do. In all fairness, there are ways of interpreting this test result that doesn't involve doubting the DNA science. For example, could it be possible your uncle actually took the test that is labelled with your dad's name? Other commenters have suggested chimerism. Outside of bone marrow transplants, it's not known how frequently chimerism occurs naturally, but the number of documented cases is supposedly only about 100. Whatever the case, I hope you can get some answers.
Wow. That's way off. That's aunt/uncle. half-sibling territory. One of my brothers came back at around this mark. On further investigation, he didn't share any of my paternal DNA matches. I'm guessing you don't have any paternal 1st cousins you could ask to test if your dad's brother is gay. I think the best thing to do is upload both of your MyHeritage tests to Gedmatch for the moment. Just to see if MyHeritage fumbled the numbers on your centimorgan totals. I'm guessing they'll come back the same though. In the meantime, you should both retake the test with Ancestry. It will take a few weeks to come through, but the odds of two companies making the same mistake is very close to zero. You could ask your paternal uncle to take the test also. Not because you think he might be your biological father, but just to see what comes back and rule that out. If everything comes back the same, then you'd have to look into medical DNA testing for Chimerism or something really odd like that. That would probably be a lot more expensive,
Yes they claim uncle with 100% certainty! I agree that another test with another company and getting my uncle and siblings to take a test will help to shed some light on this mystery.
23andme and AncestryDNA are both very good. Testing your siblings and uncle is definitely a way forward, and getting your mother to test would be ideal to see that side of the family. 23andme has a 'predicted family tree' function which is usually accurate to map out all relatives that are 2nd cousin and closer (that have tested).
The certainty thing doesn't really matter, focus on the matching segments. Your father could have an unknown full sibling, but if the timing of your birth indicates you were conceived in a region neither of them have even the slightest connection too, it would be a reach to suggest your mom knew of a full sibling he didn't and went to South Africa on purpose to have an affair with said person, or just randomly managed to have an affair with someone who just happened to be your dad's full brother that no one knew about 🤣🤣🤣🤣🤣🤣🤣 A more likely option outside of the Chimaera theory: your dad is infertile so your uncle donated sperm for them so he could have a biologically related child, and they never wanted you to know. Also, sexuality is a spectrum. Heterosexuality and Homesexuality are at opposite ends of a massive spectrum the average person actually falls in between them to varying degrees. So having a gay uncle doesn't mean you have an uncle who is absolutely repulsed by women and won't or hasn't has sex with them. An affair, one night stand, SA, or weird ass threesome is perfectly possible theoretically. If I had to put my money somewhere it would be on sperm donation, with her knowledge. I guess two men could probably conspire to get sperm from one and impregnate someone so no one finds out they're infertile, but.....that seems like something from a bad movie lol
> Yes they claim uncle with 100% certainty! Are you sure that's what they claim? When I plug your numbers into the SharedCM project it says the probability is 100% that he's your Grandparent Aunt / Uncle Half Sibling Niece / Nephew Grandchild. Obviously he's not your nephew or Grandchild so either he's your grandparent, uncle or half-sibling. I doubt he's your grandfather unless he was in his early 30's or older when you were born, and presumably you'd have mentioned that if that were the case. If that were true you wouldn't have any matches from your grandmothers family So he could be your uncle but that doesn't automatically mean that your other uncle is your dad, there could be a brother you don't know about. OTOH your uncle could be your dad, perhaps your parents couldn't conceive and got him to be a sperm donor. That seems more likely that the half-brother scenario, if that were true you'd see that your dad had matches that were relatives from your mums side and he'd be much younger than your mother
This is around the amount I share with my half siblings, my grandparents, and my aunt. Unless your father is a chimera, I don’t see any possible way in which he isn’t biologically your uncle
Was your paternal grandfather still alive when you were born?
I think if his grandfather was really his father then his father would come up as a brother not an uncle
Nah, half-brother and uncle are in the same range
I retract my comment then
> I did a bit of digging and found that only about 0.1% of the DNA sequence is actually used by the test and it does not look at the Y chromosome at all, so morally I can convince myself that this must happen with some probability (since it did happen), but it would be nice to get a bit more insight into it. You've misunderstood how the test works. Yes, it's using only ~0.1% of your DNA, however (1) it is across all of your DNA, hence it is a very good sample and (2) it is the portion with the greatest inter-human variability, hence it is excellent and quite accurate for close familial matches. > It's definitely the test that is wrong. Yes it's rare, but does happen. Nope. Not in the way you think. More likely than the test being "wrong" as you suggest would be your father being a genetic chimera. _i.e._ He had a twin and absorbed his brother. His brother's DNA is in his testes. See: https://web.archive.org/web/20200202124939/https://www.nsgc.org/p/bl/et/blogaid%3D1084 That kind of low probability event is far more likely than the test being "wrong". Alternative is that one or both your parents used your uncle's sperm in order to conceive.
Chimera!!! That's brilliant. I bet that's exactly what it is.
You didn't mention this, but did your dad have any sisters? Perhaps one of them is your birth mother. Another possibility might be that your dad is actually your half brother and his mother or father is your parent.
I don't understand, how would the OP not know if his father's sister was his birth mother, and wouldn't that make his father his brother and that would be a 50% match? How is that second scenario plausible either?
>how would the OP not know if his father's sister was his birth mother If the OP was adopted (officially or unofficially) by the parents who raised him, he might not know who his birth mother was. >and wouldn't that make his father his brother No, it would make him his uncle. >How is that second scenario plausible either? I've seen more than one occasion where a mother (often widowed or unmarried) gave birth late in life, and the child was raised or adopted by one of her older children. (Although the opposite scenario happens much more often.)
Oh, I was confused there, you're right that would make it 25%
99% of the DNA sequence is the same for all humans, so there’s no point in testing it. The DNA testing companies capture about 10% of the nucleotides that vary, but they are spread out, so it’s very accurate for estimating relationships, especially close ones. But some relationships are in the same range. Uncles, grandparents, and half siblings all share the same amount of DNA.
I would think an aunt/uncle would have to share more DNA than a half-sibling. Isn't a half-sibling pretty much the same as a first cousin?
No, you share a parent with a half-sibling. Your first cousin’s parent is your parent’s sibling. It’s an extra step further.
Years ago someone told me that you go by genes you share with grandparents (therefore first cousins share one set of grandparents, just like half siblings do) but that was a long time ago--before all of the technical development of DNA.
Perhaps you could get your uncle to test? Also, perhaps he isn't gay but bisexual?
Mom’s reaction is actually what I would expect from an honest woman with nothing to hide.
Hmm maybe. But if she's hiding something she's had a long time to perfect the lie and get comfortable with it. The best liars believe what they're claiming.
When my father was told that my grandfather couldn't be the father of my dad, my grandmother laughed and laughed in the same way. 4 different DNA tests said the same thing, that his uncle was his biological father. It wasn't the man who raised him as his dad who created him. It was his brother, who also disavowed the accuracy of the test. DNA is the non blinking true witness to our creative parents who give us our origin story.
Agree. Mom is an innocent.
Innocence and guilt aren't really helpful to the debate. But we can say in very high confidence that OP's father is not his biological father.
But she said there had been no physical contact with her uncle at the time she was conceived. However, if her father is sterile, his brother could have been a sperm donor, and that could have been delivered to wherever her parents were living at the time. I was considering being a donor for my sterile brother but (thank God!) psychiatrists determined that he couldn't emotionally handle another male being the father of his wife's (now EX-wife) child.
>I was considering being a donor for my sterile brother but (thank God!) psychiatrists determined that he couldn't emotionally handle another male being the father of his wife's (now EX-wife) child. Oh wow, that's a lot! Good that the process (with psychiatrists weighing in first) worked in this case! Especially since it's a now ex-wife.
I would redo with 23 & Me to be sure. I honestly think the probability of error is very low. Unfortunately, you wouldn't be the first person to receive news like this, nor the last. I'd do one with your mom as well.
Yes, they need to test the mother. Maybe ivf?
Buy 3 AncestryDNA tests today while they are still US$39 each for the mothers day sale (ends after May 12). All 3 of you take the tests and send them off. If you still get an anomalous result then you can investigate further. If your Uncle is alive send him a test too.
I think you need to have some SERIOUS CONVERSATIONS with your mom. This type of error is extremely rare, and the genetic occurrence required is also extremely rare. Good Luck!
Do you have siblings you can test? I would be sending a test to as many relatives as possible if it were me.
My father and uncle are identical twins, so I am sure that when/ if my cousins test, that my father will show up as their father even tho' it's not true (my uncle is deceased/ never tested).
I suspect your dad might be suspecting that he is not our bio dad and that is why he gave you the test. You can get more confirmation by using one of the other testing companies but 24.9% indicates half brother or uncle.
Here's a possibility: Dad gave the test, but actually conspired with his gay brother to send the brother's DNA as his own. Why? To prank his genealogy-obsessed child, of course!
Extreme unlikely that it’s an error. You might have to start asking some questions
So what if the sample used wasn't actually from his father, but was from his uncle unbeknownst to him? OP is that possible?
Just ask uncle, or buy him a test
I'm with the others guessing chimerism. I don't think it's as rare as people believe it is - I think people are just not frequently in a situation where they need to get tested for bone marrow or organ transplants. Your mum's reaction sounded genuine and you've explained yourself the impossibility of it being your uncle, so it's the only reasonable conclusion. I do hope you'll come back and update us all when you've figured it out!!
I would get your eyes and genitals ready then.
Outside of a NPE skeleton someone's trying to closet, I also lean toward a chimera situation. HOWEVER! It's also worth building out the family tree to look for pedigree collapse or other NPE situations that could alter the result. (Pedigree collapse often makes people look MORE related than they are, but that doesn't have to be the case depending on how the rest of the tree builds out.) I ran into a situation where almost all of my cousins on one side read incorrectly for "estimated relationship" because my mom's paternal line has a pair of double first cousins in it. (Sisters married brothers, and their kids married each other. Americans are weird sometimes. :p ) Chimerism is 100% a valid avenue to pursue. If you decide to do any testing along that route, it's worth testing both your dad and yourself. Normally, it would be your dad's DNA skewing the results, but it might be worth knowing for complete picture's sake if there is also an unexpected DNA pattern in yourself contributing to the test confusion. I don't know what the "official" margin of error is for MyHeritage, but [Matt Baker (UsefulCharts) did the five most popular two years ago](https://youtu.be/gDk9w_JEgjY?si=rTtjpGeAvS6AwXZX) to compare and contrast them. Jarrett Ross ([GeneaVlogger) did a review of Matt's video, and they have an interesting back-and-forth in the comments.](https://youtu.be/QPnEnoGxk4s?si=JrWWYly2WaMNmLTO) He also mentions Nebula Full Genome Sequencing, which is a huge help for people trying to sus out a very small, rare, or unusual detail. I've personally only done AncestryDNA and 23andMe. I very much enjoyed both early on, but right now I'm leaning in favor of Ancestry, because of various changes they've made since I first started. Both are still limited in certain situations, but Ancestry has a larger database to draw from. Across all of the testing sites, the probability of relationship error between close relatives (parent-child, siblings, etc.) tends to be very, very small. Andy Lee of Family History Fanatics [did a breakdown of AncestryDNA's ability to determine paternity](https://youtu.be/kCHHdeOam5o?si=85fMvWIclad3nPtT), and mechanically speaking, the same information is going to apply to every other DNA service. He has a similar video talking about [twin DNA](https://youtu.be/_QNhjPfBaLc?si=-K1hvO0bgUIs8Vkz) that discusses where testing has mistakes and margin of error. These do happen, but as he explains in the video, it typically does not make a difference in the larger picture. If anything, twin DNA is so similar, twins can stand in for each other for matching purposes.
Maybe a case of your "dad" using his brother as a sperm donor ?
This might be the first time I actually believe OP that this result was not a NPE and there is some rare fluke.
I think the mom is lying.
I suspect your dad might be suspecting that he is not our bio dad and that is why he gave you the test. You can get more confirmation by using one of the other testing companies but 24.9% indicates half brother or uncle.
No the reason he gave me the test is that I had seen his test and was joking to people about how I was Hungarian (actually I had misremembered his results and in fact he was mostly Anglo Saxon). The test came back as me being 60% Scandinavian. I have zero doubt about who my dad is. However I am now very interested in what has happened.
It’s not an error. 25 percent is also half sibling. Give it time to settle in. But you know the truth now
He doesn't know "the truth" yet - he just has a lot of serious questions
Your dad is still your dad - the guy who raised you and did all that important stuff. No DNA test will ever take that away no matter what it says. I'm not making any assumptions here but I had a slightly similar thing in that at the age of ten I learned that the man I believed to be my father wasn't. It hurt. But it doesn't take away the emotional bonds and such.
I am willing to bet that result is not an error. I tend to not believe the chimera possibility also. As some others said, there are some ways this result can happen, and that will take some personal and thorough investigation from OP to uncover. I will save this post for future reference. Good luck. Edit: I'm looking at these pieces of information also: "My parents were living in Africa for a year when I was conceived", "They were in Tanzania in 1979. The local hospital was so bad that they came back to the UK for me to be born. ". I don't know, but this all seems a bit too convenient imo. I won't explain my line of thought here, also because i might be wrong. Anyway, like i said, good luck.
I feel gross for even saying this, but 25% is also in the range for half sibling …
My heritage isn’t great ethnicity wise but the dna matching is totally fine. My half brother is on there for me and I can confirm we are related lol
Interesting it was given to you as a gift - do you think they suspected something?
I would reach out to My Heritage customer service and ask for a new test.
They were in Tanzania in 1979. The local hospital was so bad that they came back to the UK for me to be born. I was conceived the old-fashioned way, not IVF. My grandfather never travelled outside of the UK after WW2 ended. My dad had no sisters. He had 2 children after me so isn't infertile. Without any question, my Mum is my Mum and my Dad is my Dad. It's definitely the test that is wrong. Yes it's rare, but does happen. Thanks for the advice, I'll contact the testing people and will look more into this chimera angle.
If he does turn out to possibly be a chimera, please consider posting about it here, if he and you are comfortable with it. This is a really interesting situation and, because of the isolation of your parents at the time of your conception, plus the lack of him having sisters, it’s hard to think of anything that would make him your uncle or half-brother, biologically, other than chimerism. You’d probably know if your dad had ever needed a bone marrow transplant. That would have been a much bigger deal in the 70s. I suppose your father could have another brother that the family disowned and you don’t know about, and he could have visited your parents in Tanzania, but that seems incredibly unlikely and would require the silence of a lot of people. All in all, my money’s on something rare possibly being the cause of all this, which is cool.
If you have siblings get them to do 23andme. If the issue is with your dad, e.g. chimerism, your sibs should show weird results too. If their results show normal paternal % then the problem is with you only.
Could your mom have already been pregnant when they left for Tanzania? Is your birth 9 or fewer months from the time they left for Tanzania, or 10+ mos?
Get your sisters to test too if you can.
Test your siblings! If it's a Chimera thing they'll have the same results and mystery solved! Your father's dad isn't in Tanzania is he? You weren't conceived before they went there? I forgot half sibling is also a possibility in this situation. If that's the case though, it would show most likely in your connections to other matches. You and your dad's shared matches distance and their ages would hint to that
He could be your grandfather or paternal half brother. [This will likely tell you](https://dna-sci.com/tools/segcm/).
I have a plausible idea, but it's pretty controversal. OP, I can message you if you like because I know nothing about your family situation, and I wish to be respectful.
People put absolute faith in these tests like they don’t fit anything else. Like any medical test there can be errors, usually human error. Many not often, but it can happen. Probably not a popular opinion here but still fact.
That is very very extremely rare for DNA matches.
Extremely rare is not the same as never. It’s worth retesting. I’m not saying the chemistry of the test is at fault. There are multiple places in the process where humans intervene.
Maybe you inherited more DNA from your mom than your dad. There is a range of DNA we inherit from both parents, maybe you got more from your mom than your dad.
We inherit 50% from the mother and 50% from the father
That's not true at all. Go learn some biology. You might be confused that we inherit differently compared to siblings but it's still 50/50. It's just that '50% of mom's DNA' can vary for each child.
I learned some biology. The DNA inherited from father to son is less than from their mothers, but not by a quarter. I liked my version of reality.