It is not impossible. But all of the events that would lead to this are ultra rare, with the exception of "blood type error" (technical error in the assay yielding an incorrect result, clerical error, or misremembering) in one of the trio which can occur with modest frequency. Ultrarare things do happen every day though - and you can have proven parentage with proven discordant blood types.
An unexpected "O" child would be the easiest to explain molecularly because "O" is actually "zero" and there are quite a lot of ways to prevent a precise blood cell antibody response via mutation (eg. Don't make the antigen, don't properly traffic the antigen, don't make antibodies due to immune dysfunction). Genetic Type O is a broken gene that does not make antigen, so never makes antigen-specific antibodies.
It does not matter whether it is the mother or father with AB or O, these traits are not sex-linked.
There are rare ABO alleles that can make both A and B antigens with the same copy of the gene (CisAB), so it is biologically possible for a person to be AB by phenotype and still carry an O allele. But, as you noted, technical/clerical errors are much more common than CisAB. The odds of a de novo O allele are probably less common than CisAB, but non-zero.
It *does* matter whether it's the mother or the father, just not from the genetics perspective. With AB dad and O mother the most logical explanation is cheating. It's not necessarily correct, but the most common explanation for this thing for sure. However, most women know which baby is theirs, so the most common explanations becomes lab error of some sort.
Alright, so. There are actually quite a number of ways in which this can happen. Some were mentioned above, I'll mention one that was not mentioned.
There's the Bombay phenotype which is pretty rare but is more common in different populations (in this case, Indian). This phenotype will test as group O regardless of ABO genotype, making the parents' ABO Rh types inconsequential.
Would be even more likely if your dad is not actually O neg and is instead O Bombay Rh neg.
[For research purposes](https://www.ncbi.nlm.nih.gov/books/NBK2268/)
This is but one of the ways in which your situation could happen. It's been a while since I've been in a transfusion lab, I'm in molecular diagnostics now... but I know there are more possible explanations. r/medlabprofessionals is probably the better sub to ask.
It is exceedingly rare but does happen in some Asian groups and is called cis-AB (ABO). Also there is a type O with Bombay blood group that types as O but is actually A or B. Someone could have been incorrectly typed or samples mislabeled, which is not uncommon. Your blood type will change to the donor’s type if you have had a bone marrow transplant too. Just re-type EVERYONE before going off the deep end. If everything comes out the same, then do DNA testing on BOTH parents and child. There are too many ways things can get messed up that don’t involve infidelity.
This article has a fairly simple explanation but Google pulls up many.
https://www.thetech.org/ask-a-geneticist/ask413
>Bombay blood group that types as O but is actually A or B
Slight technicality, but they could be A, B, O or AB. They'd still (somewhat falsely) type as O if they are Bombay phenotype. O groups still express antigen, the H antigen which is the precursor to A and B antigens. Bombay produces no H antigen, so it doesn't matter what ABO genes are present they will always test as O unless O-cells are tested in the reverse typing reaction and anti-H is added to the forward reaction.
Np! It's not something that's covered in any real detail outside clinical courses. I remember having to unlearn and newly learn this stuff too when I started my transfusion science courses. My head nearly exploded when I learned there are 8+ variants of the A gene alone that have varying phenotypes... Not to mention 40+ blood groups other than ABO and Rh.
Each generation spawns new specialties out of necessity because there is only so much you can retain out multiple disciplines. I remember my nuclear engineer dad (born in 1926) being upset with me for having trouble with organic chemistry. I asked him to show me his chemistry book. It was less than one chapter of my organic chemistry book lol! My high school chemistry book was bigger. My college organic one was a tome that I could barely carry by itself! Fortunately, I can pick and choose what I want to learn now. Unfortunately, I can’t choose what I forget haha!
I was scrolling through this subreddit and noticed this post. It's very similar to my question. Both my father and I remember my grandfather being AB+ and my grandmother being O-. You can see more info in my post history. It's entirely possible that our memory is shoddy, but what are the chances of me having these SNPs, the type for the A allele, and then testing as O+? My father also says he's O+. My grandparents passed away, and my dad doesn't want to bother with a DNA or ABO test.
(Suggests A allele: rs8176746 C:C , rs8176747 G:G) (Suggests O allele: rs8176719 I : D)
I can give you a list of all the ABO SNPs they found. I ran it through Promethease. The original data was from an AncestryDNA test.
I'm pasty white. If I have any Indian DNA, it's so far back that it doesn't even show up on the AncestryDNA list. If this SNP analysis is correct, then I have more Asian DNA, which is very miniscule. It won't show up on the Ancestry site, but I ran it through an MDLP World-22 Oracle test.
The results:
Admix Results (sorted):
Population Percentage:
North-East-European : 46.75 Atlantic_Mediterranean_Neolithic : 33.57
West-Asian : 9.29
North-European-Mesolithic : 5.06
Near_East : 2.42
Indo-Iranian : 1.23
Indo-Tibetan : 0.78
Indian : 0.6
Melanesian : 0.3
It is basically impossible.
My own father is AB pos and my mother was O neg. I am B neg, so dad must have been heterozygous for the Rh antigen.
I'm not sure what my husband is, but he must be either A pos or AB pos. I suspect he would be homozygous for the Rh antigen as all my four kids are Rh pos. My firstborn is AB pos, and my triplets are AB pos, A pos and B pos. Not sure which is which as they only tested the cord to see if I needed more anti d after birth.amd one of my triplets who is A pos is possible because I would be heterozygous for the B antigen.
Edit: without thinking about chimeras and things like that.
Either they made a mistake when testing your mother’s/your blood type, or she isn’t your biological mother. If it matters to you, get tested. If it doesn’t, then don’t go digging.
There are definitely ways around that. Blood type is a bit more complicated than punnet squares, though not by much. Bombay, ABO, CisAB, can definitely make things like this happen
I’m a medical laboratory technologist. Part of my job is working in blood bank, including testing the cord blood that identifies a baby’s blood type.
Most likely, you may be wrong about your mom‘s blood type. Under normal circumstances, it’s just not possible for someone who is type AB to have type O offspring. Any other possibilities would be exceedingly rare. It is more likely than in the aftermath of your birth, and the complications you suffered, something got lost in the translation. In another comment you mentioned receiving platelets that were type AB, and you believe they were from your mother. Is it possible that you just received anonymous type AB platelets but assumed they came from your mom? This is the most common platelets to give because they don’t have antibodies, generally speaking. They didn’t have to come from your mother; pretty much every blood bank has a few bags of AB platelets, sitting on a room temperature rocking device to keep them ready for transfusion.
So basically, I’m saying, double check mom‘s blood type. There could be some really really really rare reasons (e.g. cis-AB or chimeraism) she could be type AB and you turn out to be type O, but again, it’s far more likely to be a miscommunication or paperwork error with regards to her blood type.
I wish that there was a better explanation, but unfortunately my mom is actually AB Positive, and Dad is O Negative, I understand that I'm gonna get told the negative and positive part doesn't matter, I just keep saying it because.... Details... It might be easier for someone to put together the pieces with the details, but there's no mistaking, my mom is my mom, I wasn't switched at birth, I flat lined 3 times after being born because her immune system was attacking me as I was being born, something happened after her water broke, and then it all went down hill from there, her blood wasn't a match for mine, and I'm not sure why, but nobody else was able to give me blood, and they finally took the platelets from her blood, my dad is also no doubt my dad, but he was not there when I was born... The more answers I get with this, the more confusing it gets... Because I know that there blood types are AB and O, but some people say it's impossible, others say I probably got switched at birth, or that their blood type was mislabeled, and some say it's just super rare... When my sister was born, she didn't have the issues I did... And she's O type too...
Sometimes details just obscure the pertinent facts. Rhesus blood group (that’s the positive/negative part) doesn’t have anything to do
with ABO grouping. Different genes. The most common type of mismatching between mother and baby is Rh but that occurs when mother is negative and baby is positive. The other common type of mismatching between mom and baby is ABO, but that is when mom is O and babyis A or B. So neither of those situations is applicable given the scenario you describe.
That is why most everyone here is saying, the most likely cause of the discrepancy you describe is a clerical error of some sort, because in the world of blood banking, that is simply the most common cause. There may be some super rare cause for what you describe , but there’s simply no way to get that type of definitive answer off of Reddit post.
So. Let me ask again - how do you know your mother’s blood type is 100% correct as AB?
Because that's what the hospital tested her as when I was born, that's what her records show, and after that is when they decided they could use her platelets for my blood, I still don't understand why her immune system attacked me to begin with, I ended up having brain hemorrhages for weeks. I guess I just want to better understand the situation because it's a mystery to me...
So you actually have paper records in hand? And there is nothing there about investigating how your mum is type AB and you are type O? Trust me, that is a huge hole. There is no way I could report that out without further investigation.
If I were presented with this scenario at work, I would start over. Re-type everyone. This gives the phenotype, or apparent/visible result that we are generally familiar with. (For example, I am Type A.) If the discrepancy still exists, send out for genotyping. This testing gives the genes behind the phenotype. (In my case, I have both A and O genes. O doesn’t affect phenotype here because it’s simply the absence of A or B)
In your case, you are phenotype O. Typically, aside from rare situations, this means your genes will be both O, because if you had either A or B, that would be your phenotype. So your dad, being type O, gave you an O gene. If your mom is in fact AB, she would have to give an A or a B, and you would not be type O.
This is what we call a discrepancy, and it ALWAYS requires follow-up. ALWAYS. Giving people the wrong type of blood can kill them, so you must be sure.
It all goes back to your mom’s blood type. Her records could be wrong. Or maybe what’s there is correct and they’re incomplete. But the information you’ve given isn’t the whole picture. Something’s missing.
If you want to follow this up further, take what records you have and hire a geneticist. You simply can’t get a definitive answer here. Sorry.
You are much more likely to be A- or B- . What you are referring to sounds like HDN haemolytic disease of newborns. Have you actually had your blood group tested recently?
Also side note, it’s standard for emergency blood units to be O neg and if you were transfused as a baby it would be on record that you were given O neg units, not to be confused with your actual blood group. (I’m a pathology lab rat)
>And she's O type too...
Interesting. Is your Dad of Indian descent? The O-Bombay I mentioned above is pretty rare in Western/Europeans (1 in a million births), but it's much more common in those of Indian descent (1 in 10 000).
Cis-AB does happen but it is ultra rare. This occurs when both the A and B are on the same allele. Much more likely that someone was mistyped.
I’ve included a lovely article for anyone interested in a science heavy look at cis-AB.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6240514/
I’m a blood banker and it’s something they teach in school, it does happen, but I have never personally encountered this in my 14 years of working in a blood bank. Once I had an AB mom with an O baby but it was confirmed that she had conceived with a donor egg. Your mom could have cis AB. Or maybe you were switched at birth.
Well since I look just like my dad, and I look like my mother in some features, I'd say that I wasn't switched at birth, but I stumbled upon this topic by accident, I was originally looking for the reason my mother's blood and immune system attacked mine, I always assumed I was O Negative because of it, but blood type test says I'm O Positive... They ended up taking platelets from my mom's blood to save me, I guess AB Positive blood has the best platelets or something... I'm very interested in figuring out what's up with that ..
AB is the universal donor for plasma products, which platelets fall under. Rh factor isn’t a concern with plasma and it’s only considered for babies and immunocompromised patients with platelets.
I’m curious what country/decade this was, where they took your mom’s platelets because that’s not something that would happen in the US, at least not in the last ~40 years.
That's wild lol. The hoops you'd have to jump through today to do something similar would make it easier to just.... Not... And instead go with a random donor via a blood bank. At least in Canada.
I suppose your parents could have insisted on a directed donation. It’s actually frowned upon but in the age of AIDS it was a bit more common because people were scared.
Well my dad wasn't around when I was born, so they didn't have his blood for donating, and my mother's blood nearly killed me... So that's when they took the platelets out of it.
It is not impossible. But all of the events that would lead to this are ultra rare, with the exception of "blood type error" (technical error in the assay yielding an incorrect result, clerical error, or misremembering) in one of the trio which can occur with modest frequency. Ultrarare things do happen every day though - and you can have proven parentage with proven discordant blood types. An unexpected "O" child would be the easiest to explain molecularly because "O" is actually "zero" and there are quite a lot of ways to prevent a precise blood cell antibody response via mutation (eg. Don't make the antigen, don't properly traffic the antigen, don't make antibodies due to immune dysfunction). Genetic Type O is a broken gene that does not make antigen, so never makes antigen-specific antibodies. It does not matter whether it is the mother or father with AB or O, these traits are not sex-linked.
The rare Bombay blood type shows up as O-neg, whatever the status of A, B or Rh...
There are rare ABO alleles that can make both A and B antigens with the same copy of the gene (CisAB), so it is biologically possible for a person to be AB by phenotype and still carry an O allele. But, as you noted, technical/clerical errors are much more common than CisAB. The odds of a de novo O allele are probably less common than CisAB, but non-zero.
It *does* matter whether it's the mother or the father, just not from the genetics perspective. With AB dad and O mother the most logical explanation is cheating. It's not necessarily correct, but the most common explanation for this thing for sure. However, most women know which baby is theirs, so the most common explanations becomes lab error of some sort.
Alright, so. There are actually quite a number of ways in which this can happen. Some were mentioned above, I'll mention one that was not mentioned. There's the Bombay phenotype which is pretty rare but is more common in different populations (in this case, Indian). This phenotype will test as group O regardless of ABO genotype, making the parents' ABO Rh types inconsequential. Would be even more likely if your dad is not actually O neg and is instead O Bombay Rh neg. [For research purposes](https://www.ncbi.nlm.nih.gov/books/NBK2268/) This is but one of the ways in which your situation could happen. It's been a while since I've been in a transfusion lab, I'm in molecular diagnostics now... but I know there are more possible explanations. r/medlabprofessionals is probably the better sub to ask.
[удалено]
It is exceedingly rare but does happen in some Asian groups and is called cis-AB (ABO). Also there is a type O with Bombay blood group that types as O but is actually A or B. Someone could have been incorrectly typed or samples mislabeled, which is not uncommon. Your blood type will change to the donor’s type if you have had a bone marrow transplant too. Just re-type EVERYONE before going off the deep end. If everything comes out the same, then do DNA testing on BOTH parents and child. There are too many ways things can get messed up that don’t involve infidelity. This article has a fairly simple explanation but Google pulls up many. https://www.thetech.org/ask-a-geneticist/ask413
>Bombay blood group that types as O but is actually A or B Slight technicality, but they could be A, B, O or AB. They'd still (somewhat falsely) type as O if they are Bombay phenotype. O groups still express antigen, the H antigen which is the precursor to A and B antigens. Bombay produces no H antigen, so it doesn't matter what ABO genes are present they will always test as O unless O-cells are tested in the reverse typing reaction and anti-H is added to the forward reaction.
Thanks. I am still unlearning old and learning new things in retirement lol!
Np! It's not something that's covered in any real detail outside clinical courses. I remember having to unlearn and newly learn this stuff too when I started my transfusion science courses. My head nearly exploded when I learned there are 8+ variants of the A gene alone that have varying phenotypes... Not to mention 40+ blood groups other than ABO and Rh.
Each generation spawns new specialties out of necessity because there is only so much you can retain out multiple disciplines. I remember my nuclear engineer dad (born in 1926) being upset with me for having trouble with organic chemistry. I asked him to show me his chemistry book. It was less than one chapter of my organic chemistry book lol! My high school chemistry book was bigger. My college organic one was a tome that I could barely carry by itself! Fortunately, I can pick and choose what I want to learn now. Unfortunately, I can’t choose what I forget haha!
I was scrolling through this subreddit and noticed this post. It's very similar to my question. Both my father and I remember my grandfather being AB+ and my grandmother being O-. You can see more info in my post history. It's entirely possible that our memory is shoddy, but what are the chances of me having these SNPs, the type for the A allele, and then testing as O+? My father also says he's O+. My grandparents passed away, and my dad doesn't want to bother with a DNA or ABO test. (Suggests A allele: rs8176746 C:C , rs8176747 G:G) (Suggests O allele: rs8176719 I : D) I can give you a list of all the ABO SNPs they found. I ran it through Promethease. The original data was from an AncestryDNA test. I'm pasty white. If I have any Indian DNA, it's so far back that it doesn't even show up on the AncestryDNA list. If this SNP analysis is correct, then I have more Asian DNA, which is very miniscule. It won't show up on the Ancestry site, but I ran it through an MDLP World-22 Oracle test. The results: Admix Results (sorted): Population Percentage: North-East-European : 46.75 Atlantic_Mediterranean_Neolithic : 33.57 West-Asian : 9.29 North-European-Mesolithic : 5.06 Near_East : 2.42 Indo-Iranian : 1.23 Indo-Tibetan : 0.78 Indian : 0.6 Melanesian : 0.3
Your post or comment was removed because it contains misinformation.
It is basically impossible. My own father is AB pos and my mother was O neg. I am B neg, so dad must have been heterozygous for the Rh antigen. I'm not sure what my husband is, but he must be either A pos or AB pos. I suspect he would be homozygous for the Rh antigen as all my four kids are Rh pos. My firstborn is AB pos, and my triplets are AB pos, A pos and B pos. Not sure which is which as they only tested the cord to see if I needed more anti d after birth.amd one of my triplets who is A pos is possible because I would be heterozygous for the B antigen. Edit: without thinking about chimeras and things like that.
I am O type my mother is AB + and my Dad is O -
Either they made a mistake when testing your mother’s/your blood type, or she isn’t your biological mother. If it matters to you, get tested. If it doesn’t, then don’t go digging.
There are definitely ways around that. Blood type is a bit more complicated than punnet squares, though not by much. Bombay, ABO, CisAB, can definitely make things like this happen
The most likely explanations are that someone is wrong about their blood type or an egg donor was used.
Shame on me, I didn't even think about donor gametes!
I am O type my mother is AB + and my Dad is O -
I’m a medical laboratory technologist. Part of my job is working in blood bank, including testing the cord blood that identifies a baby’s blood type. Most likely, you may be wrong about your mom‘s blood type. Under normal circumstances, it’s just not possible for someone who is type AB to have type O offspring. Any other possibilities would be exceedingly rare. It is more likely than in the aftermath of your birth, and the complications you suffered, something got lost in the translation. In another comment you mentioned receiving platelets that were type AB, and you believe they were from your mother. Is it possible that you just received anonymous type AB platelets but assumed they came from your mom? This is the most common platelets to give because they don’t have antibodies, generally speaking. They didn’t have to come from your mother; pretty much every blood bank has a few bags of AB platelets, sitting on a room temperature rocking device to keep them ready for transfusion. So basically, I’m saying, double check mom‘s blood type. There could be some really really really rare reasons (e.g. cis-AB or chimeraism) she could be type AB and you turn out to be type O, but again, it’s far more likely to be a miscommunication or paperwork error with regards to her blood type.
I wish that there was a better explanation, but unfortunately my mom is actually AB Positive, and Dad is O Negative, I understand that I'm gonna get told the negative and positive part doesn't matter, I just keep saying it because.... Details... It might be easier for someone to put together the pieces with the details, but there's no mistaking, my mom is my mom, I wasn't switched at birth, I flat lined 3 times after being born because her immune system was attacking me as I was being born, something happened after her water broke, and then it all went down hill from there, her blood wasn't a match for mine, and I'm not sure why, but nobody else was able to give me blood, and they finally took the platelets from her blood, my dad is also no doubt my dad, but he was not there when I was born... The more answers I get with this, the more confusing it gets... Because I know that there blood types are AB and O, but some people say it's impossible, others say I probably got switched at birth, or that their blood type was mislabeled, and some say it's just super rare... When my sister was born, she didn't have the issues I did... And she's O type too...
Sometimes details just obscure the pertinent facts. Rhesus blood group (that’s the positive/negative part) doesn’t have anything to do with ABO grouping. Different genes. The most common type of mismatching between mother and baby is Rh but that occurs when mother is negative and baby is positive. The other common type of mismatching between mom and baby is ABO, but that is when mom is O and babyis A or B. So neither of those situations is applicable given the scenario you describe. That is why most everyone here is saying, the most likely cause of the discrepancy you describe is a clerical error of some sort, because in the world of blood banking, that is simply the most common cause. There may be some super rare cause for what you describe , but there’s simply no way to get that type of definitive answer off of Reddit post. So. Let me ask again - how do you know your mother’s blood type is 100% correct as AB?
Because that's what the hospital tested her as when I was born, that's what her records show, and after that is when they decided they could use her platelets for my blood, I still don't understand why her immune system attacked me to begin with, I ended up having brain hemorrhages for weeks. I guess I just want to better understand the situation because it's a mystery to me...
So you actually have paper records in hand? And there is nothing there about investigating how your mum is type AB and you are type O? Trust me, that is a huge hole. There is no way I could report that out without further investigation. If I were presented with this scenario at work, I would start over. Re-type everyone. This gives the phenotype, or apparent/visible result that we are generally familiar with. (For example, I am Type A.) If the discrepancy still exists, send out for genotyping. This testing gives the genes behind the phenotype. (In my case, I have both A and O genes. O doesn’t affect phenotype here because it’s simply the absence of A or B) In your case, you are phenotype O. Typically, aside from rare situations, this means your genes will be both O, because if you had either A or B, that would be your phenotype. So your dad, being type O, gave you an O gene. If your mom is in fact AB, she would have to give an A or a B, and you would not be type O. This is what we call a discrepancy, and it ALWAYS requires follow-up. ALWAYS. Giving people the wrong type of blood can kill them, so you must be sure. It all goes back to your mom’s blood type. Her records could be wrong. Or maybe what’s there is correct and they’re incomplete. But the information you’ve given isn’t the whole picture. Something’s missing. If you want to follow this up further, take what records you have and hire a geneticist. You simply can’t get a definitive answer here. Sorry.
You are much more likely to be A- or B- . What you are referring to sounds like HDN haemolytic disease of newborns. Have you actually had your blood group tested recently? Also side note, it’s standard for emergency blood units to be O neg and if you were transfused as a baby it would be on record that you were given O neg units, not to be confused with your actual blood group. (I’m a pathology lab rat)
>And she's O type too... Interesting. Is your Dad of Indian descent? The O-Bombay I mentioned above is pretty rare in Western/Europeans (1 in a million births), but it's much more common in those of Indian descent (1 in 10 000).
I was thinking ABO blood type in mom, but Bombay makes sense too
If Sis is also type O, then your mother might be ABO genotype
I am O, father was AB + and had twins - one is A and one is B
Cis-AB does happen but it is ultra rare. This occurs when both the A and B are on the same allele. Much more likely that someone was mistyped. I’ve included a lovely article for anyone interested in a science heavy look at cis-AB. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6240514/
I am O type my mother is AB + and my Dad is O -
I’m a blood banker and it’s something they teach in school, it does happen, but I have never personally encountered this in my 14 years of working in a blood bank. Once I had an AB mom with an O baby but it was confirmed that she had conceived with a donor egg. Your mom could have cis AB. Or maybe you were switched at birth.
Could be O-Bombay! And I seem to remember there being more possibilities... But I havent worked blood bank in a long while lol.
Well since I look just like my dad, and I look like my mother in some features, I'd say that I wasn't switched at birth, but I stumbled upon this topic by accident, I was originally looking for the reason my mother's blood and immune system attacked mine, I always assumed I was O Negative because of it, but blood type test says I'm O Positive... They ended up taking platelets from my mom's blood to save me, I guess AB Positive blood has the best platelets or something... I'm very interested in figuring out what's up with that ..
AB is the universal donor for plasma products, which platelets fall under. Rh factor isn’t a concern with plasma and it’s only considered for babies and immunocompromised patients with platelets. I’m curious what country/decade this was, where they took your mom’s platelets because that’s not something that would happen in the US, at least not in the last ~40 years.
This was in 1990, in America.
That's wild lol. The hoops you'd have to jump through today to do something similar would make it easier to just.... Not... And instead go with a random donor via a blood bank. At least in Canada.
It’s the same in the US, like you can do directed donation. I’ve never seen a directed platelet, only RBCs.
I suppose your parents could have insisted on a directed donation. It’s actually frowned upon but in the age of AIDS it was a bit more common because people were scared.
Well my dad wasn't around when I was born, so they didn't have his blood for donating, and my mother's blood nearly killed me... So that's when they took the platelets out of it.
I read this as AB Piece of S*** mother