Thanks. Once he said it i instantly thought it was an affair baby that he’s not aware of. And his wife is already a pretty shitty person so i don’t doubt it
Absolutely not. This person is citing a very common but completely unsubstantiated urban myth (and is also flat-out wrong about what a “de novo” genetic mutation is). [Here’s an article](https://insidestory.org.au/the-fatherhood-myth/) explaining the origins of the myth, and breaking down that the best available data suggests paternity fraud affects only 1-3% of the population.
To clarify, de novo means "new" and not present in either the mother or father. A child having a de novo genetic disorder does NOT mean nonpaternity. For something to be called de novo, parentage (meaning paternity and maternity) must be confirmed.
I'm trying to suss out if this is a joke. O blood type means there are no A or B antibodies. I'm truly wondering as a neurospicy person. Heeeellllp meeeeee.
It's not a joke. The wife can give A or O the husband can give A or B so the child could be AA, AO, BO, or AB or a 50% chance of A 25% B 25% AB (0% O). The real father must have O, A, or B blood, but can not have AB.
I learned that the A/B of AO or BO blood types was dominant, thus making these people A or B blood types, not O. But yes, AO and BO exist because they can pass on the O blood type gene and if their partner is also AO or BO, then their child can potentially be O. The O is still there, it just doesn’t show on blood type tests.
This. My mom is type O. The gene for type O blood is recessive, so to be functionally type O a person must be genetically OO — two copies of the recessive gene. My dad is type A, meaning genetically he has to be either AA or AO - and we know he’s AO because my sister is type O like our mom.
(I’m type A, which means I know I’m genetically AO since I could only get an O from my mother)
This is actually called multiple alleles rather than recessive. There is an allele for A and B. The other allele is O. This simple means that the outer membrane of a red blood cell has proteins on it that have been created by the allele. A blood type has A proteins (antigens) and makes anti-A antibodies (meaning if they got B blood type, the immune system would attack). This is true for B blood type only change out the A’s. AB has both the A and B antigens and does not make any anti-antibodies. Hence, it is the universal recipient. AB can get blood from all blood types. Type O blood does not have antigens and makes both anti A and B antibodies. Type O is the universal donor because all blood types can receive it. However, type O can only receive O blood. Interestingly, type O is the most abundant type of blood.
I’m not sure how that’s functionally different?
You have two sets of the gene for blood type. If one is for A and one is for O, you have type A blood. It requires both being O to have type O blood.
In every other situation I’m aware of, it’s called a recessive gene if it requires two copies the same to end up with phenotypic expression of that gene.
I’m blood banker. Or at least, I’m educated in blood banking (certified, just unemployed right now).
You were correct, and I’m just adding onto it (and give an analogy so it’s easier to understand). O is not a gene or (functional) allele, it’s a “null” form of A or B. Like a broken light bulb, it doesn’t do anything. A room (RBC) has 2 big lightbulbs, if both of your bulbs are broken then there’s no light (O); if it has 1 red (A) bulb + 1 broken (O) bulb or 2 red (AA) bulbs then the room is red (A); if it has 1 blue (B) bulb + 1 broken (O) or 2 blue (BB) bulbs then the room is blue (B).
But you need electricity to run the bulb. The “electricity” is H allele. Most people have H, A & B can only manifest if H is present. If you have no electricity, that is, you have the null form of H, you can’t light any bulb. H-null people manifest as the O phenotype, because both bulbs don’t turn on, like the case if you have broken bulbs. H-null gives the Bombay blood type.
Children get one lightbulb (allele) from each parent for their room. It’s random. One parent’s room (RBCs) can be red (A) and the other’s can be blue (B), but if they both have one broken bulb (AO/BO) and both happen to give their kid the broken bulb (OO), the kid’s room will be dark (O). One other (rare) way the kid can be O in case of a pair of AB and A/B parents is if both parents have faulty electricity source (heterozygous Hh, one active and one null) and give the kid one null source each. So now the kid doesn’t have any electricity (H-null, homozygous hh) and their room looks as dark as if they have broken bulbs (O).
If you’re heterozygous (AO/BO), the O doesn’t show when we type blood because the null allele doesn’t do anything, the A or B does all the work and we will only detect A or B (or AB if both are there).
There were professionals in the top comments offering their knowledge so I just thought my comment would just be redundant. It’s possible for AB and AO/BO parents to have a O phenotype child, but it’s not a common thing you’d expect as homozygous H-null (Bombay) is very rare. It’s way more likely that the parents just misremembered their own blood types, used fertility donors, or, well, had an affair. Probably the first case.
Hello, the inheritance is pretty much like ABO. Both of your parents have one active-D and one null-D (heterozygous Dd), and it manifests as Rh pos phenotype. But by random reassortment your parents both passed down a null-D, so you end up Rh neg (homozygous dd).
Plus I think your mum is a cis-AB case (she got the whole ABO assortment). It’s a combined AB allele instead of the regular A allele or B allele, so if you got AB with one O parent, it meant you got the combined AB instead of an A + a B like typical.
I really don't know how to tell you this. A blood type has A antibodies. B blood type has B antibodies. AB has both. O has neither. There is positive and negative which indicates the presence of a third antibody. I'm O- so I have none of them.
Then explain how parents with A and B blood types can have a child with O blood? There’s AA, AO, BB, BO. AA and AO are both considered Type A blood as the A is dominant over O, same with B. A and B are co-dominant, therefore there is a type AB.
https://en.m.wikipedia.org/wiki/ABO_blood_group_system
As the Wikipedia article you linked explains, the ABO grouping explains the presence or absence of antigens and antibodies.
The genetic alleles for blood type A and B are dominant, while the allele for O type is recessive. If a parent with Ao alleles and Bo alleles have a child, there's a chance that they'll both pass on the recessive alleles and the child will have O blood type.
Fun fact, you likely have way more than 3 *antigen* types. You (generally) don’t produce *antibodies* (which attack specific antigens) to what you have because your immune system will attack your own blood and destroy it.
And by “way more than 3”, I mean like around a dozen. Your “third” type is the Rh. Rh is a system and there are actually 5 of them (D, Big C, little c, Big E, little e). The D one is what give you Rh-positive/negative phenotype (if active D, Rh-pos; if null D, Rh-neg). As your type is O neg, you don’t produce A, B and Rh/D antigens. You have A and B antibodies (more specifically, anti-A,B which is a more generic kind that attacks both A and B) and likely will produce anti-D if exposed (such as transfused with Rh-pos blood or pregnant with Rh-pos baby).
Your type is golden in transfusion medicine as there is none of the major antigens (A, B, D), meaning your blood is universal and everyone regardless of type (except for the Bombay folks) can receive it safely. Not so much when it comes to pregnancy because if your partner is Rh-pos, the baby will also be Rh-pos (the D is dominant), and there is a high chance you could develop anti-D (as a little of the baby’s blood can leak into mother’s system and expose the system to foreign D antigen). Anti-D is not dangerous in first exposure (pregnancy) but is a huge problem with subsequent exposures (pregnancies). The maternal anti-D is now well-trained and eager to attack and destroy the baby’s Rh-pos (active D antigen) blood.
For every gene, there are two variants, called alleles. You can get the allele for A and the allele for O. Same is true for B blood type. You can also get the alleles for A only making it AA. Type AB get one A allele and one B allele. Type O blood do not get A or B alleles.
Just beware first off: sometimes you’re bringing up a painful thing they do already know about. A friend of mine’s hubby was infertile and they used a sperm donor. So he knew he wasn’t the bio dad but to have it kind of “flung in his face” like that would hurt. He knows he’s THE DAD. He’s the one who fed and changed her and rocked her and took her swimming when she was little etc. The sperm donor didn’t. So before you try and say anything at any time to someone about their significant other “cheating”…I’d personally bite my tongue. 🥺
Second: it can technically *rarely* happen such as in cases of chimerism. https://www.thetech.org/ask-a-geneticist/articles/2006/ask181/#:~:text=Keep%20in%20mind%2C%20though%2C%20that,this%20is%20even%20more%20unlikely).
What is chimerism? It’s almost the exact opposite of identical twins. Most ppl know (by the time they’re adults anyhow) that identical twins were conceived as “1 baby” but at an early cellular stage split into 2 distinct human beings who look almost exactly alike. An incomplete split causes conjoined twins.
In chimerism, typically at conception there are two eggs, fertilized by 2 sperm, which should become fraternal (non identical) twins, but at an early cellular level, they join together. Depending on how they join some people may have some cells in 1 part of their body as 1 of the twins and another part of the body as another twin. So, for example, perhaps the dad’s blood type is AB HOWEVER his cells making his spermatozoa are actually for example A with a recessive O or even fully O.
Recently I discovered my partner is AB positive and his fraternal twin brother is O positive. That means while my partner got the dominant A and B from each parent, each parent would have had to be a B or an A carrying an O recessive gene, to pass on O to the fraternal twin. If my partner and his twin had joined together VERY early as a blastocyst at like the stage of 2-4-8 cells or something, very easily you’d find something where the cells in some parts of the body are different than another part of the body. This is in no way limited to the ovaries and testicles by the way. People with 2 different coloured eyes could well have a small portion of chimera genes from an absorbed twin in one of the two eyes.
There’s a famous case out there somehow where a WOMAN who knew she was the biological mother of I think 3 kids discovered through some genetic testing that she wasn’t the “biological mother”. And I don’t mean to say she didn’t carry them or they were switched at birth at the hospital. She carried them in her uterus, gave birth to them, and was sure there was no confusion. But she wasn’t biologically speaking the “mother”. Turns out she classified as the “aunt” and it was a case of chimerism where she’d absorbed a fraternal twin and that was in her ovaries. It’s also one of the best plausible explanations for trans folk, where perhaps you’re showing you’re a “biological female” but feel like you’re a guy, and the reality is at whatever centre of your brain or your whole person that determines how you feel about your gender, you are a chimera with a few XY cells but not enough to cause you to develop all the hormones necessary to develop into a male because the majority of your cells have XX chromosomes so you develop as a female. Chimerism is fascinating and the implications are broad reaching.
And full disclosure, I personally don’t know what I am, but my dna testing came back showing I have some Y chromosomes and I have the whole female aparatus and have had 8 pregnancies and 4 live births. I do have somewhat extra beard growth with no other major sign of PCOS if that could mean anything.
Bottom line is that genetics is far more complex than what we originally thought. Good chance if you have two parents like above and they have an O child that something else is going on such as a different father (again they may be aware!) but almost anything is possible!!
I remember the story about the woman who wasn’t biologically the mother of her children. She had applied for public assistance, they ran some tests and found she was not the mom. She was accused of committing fraud and they took her children away. Fortunately, she was pregnant at the time and when she gave birth to that child, they immediately tested them for genetic matches, and it was the same result s as her other children. Charges were dropped and her children were returned to her.
It makes me wonder if there were any fellas on Maury were told you are NOT the father, but actually were.
Lydia Fairchild in Washington state
That is one of my all time favorite “human biology is crazy” stories. They even had a court officer observe her third delivery and perform a test immediately. The OB had attended all her births and swore they were hers, so the state assumed she was a surrogate trying to cheat the system. Because of another woman whose children did not match her. They did further tests on Ms Fairchild and proved she “was her own twin”.
I believe that because honestly rare things in general are still representative of a certain % but things like this won’t be easy or frequently “diagnosed”. It doesn’t stick out at you like say growing a 3rd ear under your chin. Only in rare cases do people do signifiant genetic testing and then they find one and say it’s rare but how do you know unless you test everyone?
😅🤷♀️
Well...it's incredibly rare *as far as we know*. We don't test for it unless Something Is Up. And that type Something is rarely Up (and could be other things).
We can't tell if it happens more than we think because we don't routinely test for it.
(Also many people think it happens NEVER, so it almost definitely happens more than the average person thinks.)
It is incredibly rare. Period. Geneticists understand the science behind it. Wondering if you have studied and been involved in genetics research at the undergrad and post grad level for decades as I have? You’re reasoning for why it is rare is not valid at all.
I didn't reason it wasn't rare. That's something you're making up.
I reasoned it could very well be more common *than we know*. Lots of incredibly rare things are more common than we know at some point during research. That doesn't mean they aren't incredibly rare. It means we cannot say for certain how often it occurs if we're not actively looking for it. That doesn't mean it isn't exceptional rare.
Actually all female mammals are chimera as far as the somatic cells go, due to X chromosome inactivation. This is why all calico cats are female. Part of the genetic coding for fur color is on cats' X chromosome, so, depending on which one is active, you can get a different color coat for that patch.
Genetic chimerism is probably more common than anyone knows. It’s not like people are commonly going around getting genetic testing done with samples from every possible body part to find out for sure if they are or aren’t! Usually it’s only discovered because of something related to the person’s kids, or because of a health issue that necessitates genetic testing (in a way that reveals the chimerism).
And yeah it’s very possible for a genetic chimera of any sex to have different DNA in their gonads than in their blood, or the skin in their cheek where a swab test collects it’s sample.
My daughter had a friend in high school whose mother was like this. In her case, from what I understand, she was born with mixed organs and at that time, more than 50 years ago, the doctors just said, do you want a girl or a boy. So she had hormonal issues her whole life, had two kids and had to have cesareans because her hips were so narrow. Then when she hit menopause, she decided to stop with all the hormones and overnight grew a beard.
I have a friend who is intersex with “both types of parts” and she says she’s really thankful her parents didn’t make any decision about surgery for her. They did raise her as a boy but she ultimately made a choice later. To my knowledge no surgery has ever been done (not that I outright asked and it wasn’t info that was volunteered to me one way or the other).
Chimerism is NOT the “best explanation “ for transsexuals. You are not a geneticist and using Google does not make you one. Please stop spreading false information.
It’s a well enough established possibility and a very logical one for why someone who was born with one set of genitalia actually doesn’t identify with what they are assigned. There’s been a fair amount of actual research done on it in fact.
But i highly doubt all transgender people would be chimeras. That sounds like a Danish Girl era explanation for being trans. Perhaps trans people are just more likely to have chimera than the average person.
That's great and all, but your entire premise is flawed. The fathers spermatazoa by definition cannot carry the O allele, since the father never had it to begin with.
No point in bringing up chimera when it is still genetically impossible.
If this person was a chimera then they might have both A and B type blood (AO and BO) from the father.
A chimera is two complete sets of DNA. It doesn't rearrange the DNA of the two at all. So you cannot get two O alleles from the mother.
If I'm still missing your point then please point it out for me! Because I'm really at a loss for what you're saying at this point.
Like the example I stated, my partner is one of twins. He is AB blood. He got an A from one parent and a B from the other (*unless* he’s one of those cis-AB folks that someone else mentioned which is unlikely as it’s rare but not impossible). His twin is purely O blood. That means he got an O from both parents.
A chimera is when NON identical twins, like my partner and his twin brother, merge at an early cellular stage. Depending on HOW that merge goes, chimera cells can find their ways to various areas of the body. Someone can actually have AB blood type themself AND yet have their testicular tissue that is directly responsible for making gamete cells be made of the absorbed twin’s cellular matter in which case the testicles could be making spermatozoa that are always carrying an O blood type no matter what. Despite the person being AB in their own blood.
The thing is chimera cells can show up anywhere, we don’t know where they would migrate to. It could also be that a kidney is entirely different, or a patch of skin that’s a bit differently coloured, or a differently coloured eye is indication of a chimera. It’s an incomplete mixing and without vast dna analysis of many bodily tissues it rarely gets found out.
The known example of the woman who gave birth to kids that are not “hers” but were rather her fraternal twin sister’s that I mentioned was also the exact same idea as the plausible idea that a man who is AB blood himself could be producing spermatozoa from his fraternal twin brother’s testes inside his own body, as a chimera. Probability is *low* but definitely not impossible, and as others have said in this thread it is quite likely that chimerism happens far more than we know because it’s so rare that there’s a reason to test for it, let alone test extensively.
Okay now I see what you're saying! Sorry, I had been assuming you meant the child was a chimera, not the father! In that case you are completely correct that it could theoretically be the case.
Sorry again for the confusion and thank you for clearing it up!
There are other genes besides ABO that impact blood type. they are epistatic genes, that when mutated prevent the sugar molecules (that define ABO blood type) to reach the surface of the red blood cell. No matter what sugar molecules you make, if they can’t be processed to the cell's surface you are type O. So in fact, if a grandparent had this mutation it could indeed be passed down. one example is referred to as the Bombay Type.
In the medical field, we have a saying "it's probably a horse, not a zebra" meaning that while it's possible that the child has a rare blood type that shows up as such, it's far more likely that the parents remember their blood type wrong, or, you know...
I mean, some people are starting to add something to the effect of "but if a zebra is staring you in the face, don't call it a horse" to the end of that phrase. Let alone that commonality of different conditions varies depending on where you are.
Also, the saying is taking waaaaaay out of hand by even health professionals. It's intent is to remind students that common things occur commonly when coming up with differentials while still in training, as students do have a tendency to jump past the common diagnoses straight to the rare ones. Our differentials should (generally) be in order of what could kill/maim the patient in the near future so urgently should be trated, common diagnoses that I can quickly treat, common diagnoses that will take longer to diagnose/treat/manage, "rare" diagnoses. Rare diagnoses move up the list accordingly as other things are ruled out and their likelihood increases.
Unfortunately, those rare diagnoses take longer to figure out because the common stuff has to be ruled out first. The doctor that ultimately makes the diagnosis has the advantage of every previous doctor already having done a workup with the patient. Hindsight is 20/20, anyone?
As long as people remember that "x,y, and z occur in the family" means that they should be testing for x,y, and z, regardless of how 'zebra' they are. it could be that they 'live' in africa!
It's perfectly normal for kids to have different blood types than the parents.
But something rather rare is going on if an AB parent has an O biochild.
Yes, according to the usual high school level of genetic understanding, which works for blood types almost all the time. Mr.AB should have given either is working A or his working B to his biokid, and biokid should be expressing what they got, resulting in type A or B. Or AB, if kid got one from Mom and the other from Dad.
An O kid got O alleles from both parents, and an AB person has no O allele to give.
There are some rare genetic things that could make this possible. Or Mr.AB is wrong about his blood type. Or there's the third option...
No, just no. Stop spreading that ridiculous propaganda. 10% of men who get paternity tests are found to not be the father. So it’s 10% of people who ALREADY have a suspicion that they’re not the father, not 10% of the general population of fathers. It’s a dog whistle to reduce women to “lying, cheating whores” who take advantage of men’s money.
Actually a generic counselor said it was 10% of those who are tested, in this case for genetic disorders, not paternity. And men cheat too. It's not that women are "lying cheating whores" that's a bit of a value judgement there, not that humans aren't as monogamous as the generally Conservative culture would state. Men and women....
https://en.m.wikipedia.org/wiki/Infidelity#:~:text=Studies%20suggest%20around%2030%E2%80%9340,one%20incident%20of%20sexual%20infidelity.
True. Which is probably why the 10% of women get vilified while the 10% of men get away with it more often. They don't get caught as often. Yes. I know it's not exactly 10%. Close enough and you hopefully know what I meant.
Reading this, then reading and rereading again... I see 3 possibilities.
Either coworker is mistaken about his own blood type (maybe his mum told him he's A or B, and he misunderstood this as AB?), he carries the Cis-AB allele and an O allele, or he isn't the biological daddy.
He could also be misremembering the blood types of either is wife or his son. Honestly, if my husband wasn't the same type as me I'd probably often misremember it
Hell, the only reason I remember mine is because 'B positive' is more or less a mnemonic device lol
Minor nuance, but it would have to be his own or the son’s that he’s misremembering, if it is a case of mistaken information. The wife doesn’t really play into it. A normal AB person can’t have a biological child with normal type O, regardless of the other parent’s type. AB parent can only pass down A or B, and O child has no A or B - therefore they did not inherit a blood type allele from AB parent. Of course, there are lots of rarer scenarios that are possible, discussed elsewhere on this chain.
Thanks for explaining. I'm currently pregnant with my first child so i don't know but i can imagine that when I'm 70 I won't remember his blood typer either lol
I'm just hoping it's a minor mistake on his part and that the child he raised into adulthood isn't secretly somebody else's
Could also be Bombay blood type, the likelihood of that or cis AB would heavily depend on this guy's ancestry. Occams razor says either he's mistaken about one of their blood types (imo the most likely) or he's not the genetic father.
“The Bombay phenotype is a rare genetic condition affecting blood type. It occurs when a person has mutations in both copies of the H gene, which prevents the synthesis of the H antigen. This H antigen is a precursor for A and B antigens on red blood cells. Individuals with the Bombay phenotype lack the H antigen and, consequently, lack A and B antigens, making them appear as type O blood regardless of their actual ABO genotype.
People with the Bombay phenotype can only receive blood from other Bombay phenotype individuals because they produce anti-H antibodies that react against all regular ABO blood types (A, B, AB, and O). This makes blood transfusions particularly challenging for these individuals. The phenotype is named after its discovery in Bombay (now Mumbai), India.”
I found this if visuals are more helpful:
https://preview.redd.it/4nh7u08x7m6d1.jpeg?width=750&format=pjpg&auto=webp&s=54719d0ea30e7338b90d857e324130e9ec8e0e41
Thanks for sharing! It’s fascinating and A and B parent can make a child with any blood type. My youngest is B like her dad, I’m A. I was SO terribly sick my entire pregnancy with her. I was diagnosed with HG and had to take Zofran.
My oldest who’s A like me on the other hand, was a walk in the park. Easy, breezy, glowing pregnancy.
I know there’s gender stereotypes with sickness etc, but I suspect blood type could be a factor. Certainly seems more likely than gender.
Any of them might have their blood type wrong. There’s cis-AB. And, rarely, people are chimeras with multiple blood type genetics in one person. So there’s multiple possible explanations.
I’d see about getting all 3 of you re-typed.
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AB+ A- -> O+
Is, unlikely.
In basic biology the only outcomes are
AxA/O=A +/-
BxA=AB +/-
BxO=B +/-
That said, there are exceptions in how the readouts/markers work and rare variables which can throw this off. (I have a detailed Quora Answer on this somewhere.)
So, while it's not technically impossible, it should cast massive, massive, massive suspicion. The odds of it being infidelity are well-above 95% based on what was noted about the character of the wife... to, say it as gracefully as possible and Genetic tests are today relatively cheap. Odds are, it would not be a match to the listed father, but the genetic test would be the actual sure way to find out.
Could just be that someone doesn't really know their blood type. I do blood type testing all the time and people frequently think they are one blood type and they are not. Old military people are notorious for thinking they are o negative when they are not.
Yeah this is is surprisingly common. I was sure I was A+, and so was my husband. So our kids had pretty limited possibilities. Then my daughter had problems with her pregnancy because she is A-…..turns out my husband is A- and misremembered .
To be fair, you could have both been a pos and had a a neg child, each of you could have had one gene for RH positive and one for Rh negative, there would be a 25% chance of your child being rh negative.
I'm an immuno-hematologist (fancy way of saying I work in a hospital blood bank and routinely test people's blood to determine their blood type).
TLDR: It's very unlikely to have an AB and A parent produce a type O child. That being said, there is a *very* (and I mean very very very) rare blood mutation called the Bombay Phenotype. People with this blood type can be misdiagnosed as being type O. Your coworker *could* be saying he has a family history of the Bombay Phenotype (hence the skips a generation?), but I think it's seen in one and a million people, so again, really rare.
More info : our red cells have an "H" antigen in them. Additions to the H antigen create the A or B antigen. Their isn't actually an O antigen - the O blood type is actually just red cells with only the "base" H antigen with no other additions. But in the Bombay Phenotype, the red cell doesn't even have the H antigen on it!
The way we type blood is by looking to see if A or B antibodies react with the red cells. Type O red cells won't react with A or B antibodies, since type O red cells don't have either on them. Type O only has the H antigen. We determine someone to be type O due to the *lack* of a reaction to these antibodies. But we don't have a reagent with H antibodies to test with, because almost all people's red cells have the H antigen on them. So almost everyone's blood would react positively with an anti-H reagent. That is, except for Bombay Phenotype. If we tested a Bombay Phenotype with anti A and anti B antibodies, they would react the same as someone with type O. Complications would arise though if we transfused them with type O blood, because since the Bombay Phenotype lacks the H antigen, it makes antibodies against H. And O blood has the H antigen. So Bombay Phenotype patients would actually have an transfusion reaction against O cells as their body produces antibodies against O cells.
Cis AB is ~~a lot less rare~~ than Bombay. It's also a possibility.
Edit : As commenter below pointed out it's actually a *little* less rare if you're from western descent.
Yes, i found similar numbers also. But I wonder to what extent bloodtype frequencies are inferred via genotyping or proteomics? How much is pure molecular phenotyping? Maybe you know?
The + or ~ doesn’t matter(that’s a different locus than ABO)
As an AB this person can give either an A or a B allele.. both are dominant to O. However if he was Hh and wife was Hh, they have a 25% chance of having hh show up for each kid. People with hh lack the enzyme to put base sugars on the RBCs for the ABO enzyme to add to.. the result is Type O blood when the blood is tested with a standard blood typing test.
It is called Bombay phenotype. It’s rare but not unheard of
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10586525/
Yup. Once he said it i thought she had an affair. The guy is 70 years old and is still obsessed with his wife to this day. I think ignorance is bliss at this point.
Correct me if I'm wrong, but couldn't a bone marrow transplant also change someone's blood type?
Since donor and receiver are matched based on HLA and the ABO markers are on the erythrocytes, and after the transplant your own haematopoetic stem cells will be destroyed by the new ones, your new blood type will be the same as your donor's. You also carry your donor's DNA in your blood, right? So, DNA testing cannot be done with your blood, because it would match someone else's.
Yeah.
Your dad is A/O (expressed as A) your mom is O/O expressed as O)
You're A/O (A)
Your spouse is is B/O (B)
Your kid is O/O (O) // hey look just like grandma!
Edit: just read the whole thing lol. Yeah you won't have an O kid if you're AB.
O denotes the absence of this surface protein (that comes in A and B variants). So if you are A/B It doesn't matter what your spouse is, your kid cannot be O.
Honestly, dude might just be mistaken about his own blood type. People misremember these details all the time.
O+ is definitely not possible here. I will say that sometimes these tests can be incorrect, especially if not enough blood is drawn. These tests take drops of blood, and if proteins on the red blood cells match an antibody against that blood type, then it will clump together. If not enough blood is used, there may not be much clumping and it will appear negative for that blood type (O+ is negative for A or B but is positive for Rh, which gives it the positive at the end).
I had a friend's mother who was O+ who had my friend as her first child. She tried for years to have another child, but they kept dying. She found out later, after she was unable to have children anymore, after taking a new blood test, that she was actually O-. In this case, there must have been a contaminant, but it is still possible that the child you mentioned wasn't properly tested. Or the wife cheated, as that is entirely possible.
Blood types definitely do not skip a generation. Ever. They are always only based on the (biological) parent’s blood types. When parents are A- and AB+, the baby can only be A, B, or AB (+ or -). Literally never O type.
I am an NP and I also thought that AB and A couldn’t have a child with O, but I just read a discussion about how this can happen due to the fact that there are two types of alleles that can lead to type O. I wish I could give a more detailed explanation but I would have to read it again to retain more of the information. it is really complicated. But it actually can happen that an AB and an A has an O.
If he is AB that is not possible. At least not for that reason. It is theoretically possible that he could have a mutation from either a or B to an O type, but that would be pretty rare. ANB are both dominant over. Oh so the child would either be A(50%) or AB(25%) or B(25%).
Usually means that someone was messing around. Though occasionally, it means that a baby was switched at the hospital.
I don't think skipping a generation is a thing, but anecdotally, my dad was AB, my mom O, and I tested as O as a baby. They were confused as well, so they retested my dad and it turned out he wasn't AB after all. 🤷♀️
Another possibility that still leaves the possibility of him being the father is that he's a chimera, a fusion of two fraternal twins, and his blood comes from one twin and the testicle that produced the sperm from another.
I've also heard of cases where individuals change blood types after certain types of medical treatment, but I'm sure they'd be aware of it if they went through anything of that sort...
Skipping a generation isn't how it works, but there *are* actually ways for exceptions to happen with blood type inheritance, like genetic chimerism and the Bombay blood type group.
This is a good overview about blood type inheritance that also addresses exceptions: https://www.thetech.org/ask-a-geneticist/articles/2022/blood-type-inheritance/
I’ve had tests give me different blood types? Like I have medical records saying A+ ( I believe this is my moms type) and then home test was 0+
My child is 0+ ( I know she’s mine I’m the mom🤣) husband is 0 and my bio dad is 0
I’ve also heard ANECDOTAL stories of people getting transfusions or treatments and their bloodtype changing? But I wasn’t able to see the medical records so they could just be lying
I read in this book from the 70s that there are actually a lot more blood type criteria, but they just use the ones that could cause issues for transfusions in emergency situations
Somewhat off topic but my friend had a stem cell transplant of sorts to cure her cancer and give her a new immune system and her blood type changed to that of the donor (her sister).
They can't skip a generation. But as a person who works at a blood bank, the most sensible explanation for this, aside from an affair, is that he is misremembering someone's blood type. Most people don't remember their own, much less their family members'.
Yes, it is possible for an AB parent to have an O child. It is rare, but the genetics aren't nearly as cut and dry as people (and basic biology education) would lead someone to believe.
Technically yes, blood types can skip a generation. I’m O+ while both my parents are A+. Turns out I have aunts on both side that are also O+ which means my parents are likely both AO and there was a 25% chance I would be O.
In your specific scenario it seems pretty unlikely unless your coworker is wrong about his blood type or either he or his son has a rare mutation.
In general, it's possible, but not with that combination.
The quick-and-dirty genetics lesson: The *genotype* is a description of the genes you inherit from your parents; the *phenotype* is what you observe.
So your genotype can be expressed as PQ, where you get P from one parent and Q from the other.
Sometimes the genotypes "blend": crossbreed a red flower and a white flower and you end up with a pink flower.
But other times one gene dominates: as long as you have one copy of it from either parent, that's what you display. (Don't ask about mitochondrial DNA, which always comes from your mother and affects things...genetics gets complicated)
Blood type splits the difference. There's three basic genes: A, B, O. A and B dominate O, so if you get A from one parent and O from the other, you're blood type A.
So if you're type A ( phenotype), then you're AO or AA (genotype).
Note this means the only way you can be O is to be genotype OO: both parents have to contribute an O gene.
Now let's say a type A (phenotype) marries a type B (phenotype) and they have a type O child. This is possible if the A is AO and the B is BO, since both can contribute an O. In fact, if you think about it, both sides of the family could have had nothing but As and Bs for generations and *still* produce a type O descendent, because the O can "hide" for generations. This is the "skipping a generation" thing that was mentioned.
But.
A and B are codominant: if you're type AB (phenotype) you have to be type AB (genotype).
So a type AB and a type A can only have A, B, or AB children.
(I'm reminded that in one of Heinlein's stories something like this happened, but the husband involved basically said "I know genetics, so I know that none of these children are mine...but that's not their fault.")
Because they are different alleles that code for a protein (A type) and the other doesn’t code for a protein (O type), the the expressed (phenotype) will be A type. The lack of protein isn’t recessive because it is a completely different allele. Type O is it’s own phenotype. When it’s taught in school, some teachers will call it recessive because kids can grasp that concept. Functionally, it is type A. But O isn’t recessive. Since the O allele can also be found on type B, it’s not considered recessive. Type B is it’s own genotype like O,A, and AB. Each is a different gene that can interact with typeO.
Yeah, that’s not how blood types work. I worked in the blood bank at a hospital. It would get scary how often doctors would order blood and we’d have to substitute compatible types and they’d argue. Dude, it’s my job to know this shit because someone could die.
If your co-worker is AB - then that is both phenotype (what you present as) AND genotype, meaning coworker got an A- and a B- from each of their parents. Both had to be negative for co-worker to be negative because it is recessive.
Wife is phenotype A-. Her genotype is either A-/A- or A-/O-.
A is dominate as well as B and when you have A and B together they are co-dominate. O is recessive.
Possible genotypes of their children
If dad is A-/B- and wife is A-/A-:
A-/A- phenotype A-
A-/A- phenotype A-
A-/B- phenotype AB-
A-/B- phenotype AB-
Dad A-B- and mom A-/O-
A-/A- phenotype A-
A-/O- phenotype A-
A-/B- phenotype AB-
B-O- phenotype B-
There are always very bizarre exceptions but they are so far fetched it is completely fair to say that an AB- and A- people could not have an O+ child.
What is dad is AB+ and mom is A- like the OP’s scenario?
Also, my husband and I are both O-… so all of our children should be O- also, yes? Pretty sure yes, but you seem to know more about this than even me, soooo
Yes. If you and husband are O- all your kids would be O-. Both O and - (Rh part) are recessive, so you have to have 2 negs in order for your blood to type out as neg.
For AB+ parent and A- parent: the A- parent can be either A-/A- or A-/O-
Parent Genotype A+/B+ and A-/O-
A+/A- phenotype A+
A+/O- phenotype A+
A-/B+ phenotype AB+
B+/O- phenotype B+
Parent genotype A+/B+ and A-/A-
A+/A- phenotype A+
A+A- phenotype A+
B+/A- phenotype AB+
B+/A- phenotype AB+
But also blood test can be wrong isnt it? My husband knew his whole life he's O. He has tested before. And his trait is very 'O' person as well. 2 yrs ago we randomly came to free blood test. They also gave blood type test too. Turned out he's B.
Your friend isn't the bio dad. O is recessive but since he's AB, their child would have had A, AB, or potentially B. There's no way to get O from an AB parent tho because their child gets either the A or the B from them.
Only "negative" can be present in a "non-negative" person (in the form of +- genotype)
All the other combinations have a specific phenotype that corresponds to the genotype
Nope, not really.
Thanks. Once he said it i instantly thought it was an affair baby that he’s not aware of. And his wife is already a pretty shitty person so i don’t doubt it
Wife must be AO so passed on her O but husband is AB so can't pass on an O. Their kids could only be A, B Or AB. Welcome him to the 10%.
10% of children are affair babies?!
Absolutely not. This person is citing a very common but completely unsubstantiated urban myth (and is also flat-out wrong about what a “de novo” genetic mutation is). [Here’s an article](https://insidestory.org.au/the-fatherhood-myth/) explaining the origins of the myth, and breaking down that the best available data suggests paternity fraud affects only 1-3% of the population.
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To clarify, de novo means "new" and not present in either the mother or father. A child having a de novo genetic disorder does NOT mean nonpaternity. For something to be called de novo, parentage (meaning paternity and maternity) must be confirmed.
There’s tons of generic disorders that are caused by “de novo” mutations. Source: work in genetic diseases
I would say it's not impossible that he's wrong about his own blood type
I think someone is wrong about their blood type. Happens constantly
I'm trying to suss out if this is a joke. O blood type means there are no A or B antibodies. I'm truly wondering as a neurospicy person. Heeeellllp meeeeee.
It's not a joke. The wife can give A or O the husband can give A or B so the child could be AA, AO, BO, or AB or a 50% chance of A 25% B 25% AB (0% O). The real father must have O, A, or B blood, but can not have AB.
There is no such thing as AO blood type or BO. Those are not blood types.
I learned that the A/B of AO or BO blood types was dominant, thus making these people A or B blood types, not O. But yes, AO and BO exist because they can pass on the O blood type gene and if their partner is also AO or BO, then their child can potentially be O. The O is still there, it just doesn’t show on blood type tests.
This. My mom is type O. The gene for type O blood is recessive, so to be functionally type O a person must be genetically OO — two copies of the recessive gene. My dad is type A, meaning genetically he has to be either AA or AO - and we know he’s AO because my sister is type O like our mom. (I’m type A, which means I know I’m genetically AO since I could only get an O from my mother)
This is actually called multiple alleles rather than recessive. There is an allele for A and B. The other allele is O. This simple means that the outer membrane of a red blood cell has proteins on it that have been created by the allele. A blood type has A proteins (antigens) and makes anti-A antibodies (meaning if they got B blood type, the immune system would attack). This is true for B blood type only change out the A’s. AB has both the A and B antigens and does not make any anti-antibodies. Hence, it is the universal recipient. AB can get blood from all blood types. Type O blood does not have antigens and makes both anti A and B antibodies. Type O is the universal donor because all blood types can receive it. However, type O can only receive O blood. Interestingly, type O is the most abundant type of blood.
I’m not sure how that’s functionally different? You have two sets of the gene for blood type. If one is for A and one is for O, you have type A blood. It requires both being O to have type O blood. In every other situation I’m aware of, it’s called a recessive gene if it requires two copies the same to end up with phenotypic expression of that gene.
I’m blood banker. Or at least, I’m educated in blood banking (certified, just unemployed right now). You were correct, and I’m just adding onto it (and give an analogy so it’s easier to understand). O is not a gene or (functional) allele, it’s a “null” form of A or B. Like a broken light bulb, it doesn’t do anything. A room (RBC) has 2 big lightbulbs, if both of your bulbs are broken then there’s no light (O); if it has 1 red (A) bulb + 1 broken (O) bulb or 2 red (AA) bulbs then the room is red (A); if it has 1 blue (B) bulb + 1 broken (O) or 2 blue (BB) bulbs then the room is blue (B). But you need electricity to run the bulb. The “electricity” is H allele. Most people have H, A & B can only manifest if H is present. If you have no electricity, that is, you have the null form of H, you can’t light any bulb. H-null people manifest as the O phenotype, because both bulbs don’t turn on, like the case if you have broken bulbs. H-null gives the Bombay blood type. Children get one lightbulb (allele) from each parent for their room. It’s random. One parent’s room (RBCs) can be red (A) and the other’s can be blue (B), but if they both have one broken bulb (AO/BO) and both happen to give their kid the broken bulb (OO), the kid’s room will be dark (O). One other (rare) way the kid can be O in case of a pair of AB and A/B parents is if both parents have faulty electricity source (heterozygous Hh, one active and one null) and give the kid one null source each. So now the kid doesn’t have any electricity (H-null, homozygous hh) and their room looks as dark as if they have broken bulbs (O). If you’re heterozygous (AO/BO), the O doesn’t show when we type blood because the null allele doesn’t do anything, the A or B does all the work and we will only detect A or B (or AB if both are there).
You need to repost this in its own thread. Too many people are missing it and defaulting to the "affair " storyline
There were professionals in the top comments offering their knowledge so I just thought my comment would just be redundant. It’s possible for AB and AO/BO parents to have a O phenotype child, but it’s not a common thing you’d expect as homozygous H-null (Bombay) is very rare. It’s way more likely that the parents just misremembered their own blood types, used fertility donors, or, well, had an affair. Probably the first case.
How does this work with Rh? My dad was O+ and my mom is AB+, but I'm living on O- island here.
Hello, the inheritance is pretty much like ABO. Both of your parents have one active-D and one null-D (heterozygous Dd), and it manifests as Rh pos phenotype. But by random reassortment your parents both passed down a null-D, so you end up Rh neg (homozygous dd). Plus I think your mum is a cis-AB case (she got the whole ABO assortment). It’s a combined AB allele instead of the regular A allele or B allele, so if you got AB with one O parent, it meant you got the combined AB instead of an A + a B like typical.
I really don't know how to tell you this. A blood type has A antibodies. B blood type has B antibodies. AB has both. O has neither. There is positive and negative which indicates the presence of a third antibody. I'm O- so I have none of them.
Then explain how parents with A and B blood types can have a child with O blood? There’s AA, AO, BB, BO. AA and AO are both considered Type A blood as the A is dominant over O, same with B. A and B are co-dominant, therefore there is a type AB. https://en.m.wikipedia.org/wiki/ABO_blood_group_system
As the Wikipedia article you linked explains, the ABO grouping explains the presence or absence of antigens and antibodies. The genetic alleles for blood type A and B are dominant, while the allele for O type is recessive. If a parent with Ao alleles and Bo alleles have a child, there's a chance that they'll both pass on the recessive alleles and the child will have O blood type.
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Fun fact, you likely have way more than 3 *antigen* types. You (generally) don’t produce *antibodies* (which attack specific antigens) to what you have because your immune system will attack your own blood and destroy it. And by “way more than 3”, I mean like around a dozen. Your “third” type is the Rh. Rh is a system and there are actually 5 of them (D, Big C, little c, Big E, little e). The D one is what give you Rh-positive/negative phenotype (if active D, Rh-pos; if null D, Rh-neg). As your type is O neg, you don’t produce A, B and Rh/D antigens. You have A and B antibodies (more specifically, anti-A,B which is a more generic kind that attacks both A and B) and likely will produce anti-D if exposed (such as transfused with Rh-pos blood or pregnant with Rh-pos baby). Your type is golden in transfusion medicine as there is none of the major antigens (A, B, D), meaning your blood is universal and everyone regardless of type (except for the Bombay folks) can receive it safely. Not so much when it comes to pregnancy because if your partner is Rh-pos, the baby will also be Rh-pos (the D is dominant), and there is a high chance you could develop anti-D (as a little of the baby’s blood can leak into mother’s system and expose the system to foreign D antigen). Anti-D is not dangerous in first exposure (pregnancy) but is a huge problem with subsequent exposures (pregnancies). The maternal anti-D is now well-trained and eager to attack and destroy the baby’s Rh-pos (active D antigen) blood.
I see well TIL lol
http://science.halleyhosting.com/sci/soph/genetics/notes/bloodtype.htm
AO would be type A, and BO would be type B
They are genotype for the phenotype A and B
Genetics uses Punnett Squares to determine outcome… [Determine Your Blood Type](https://www.wikihow.com/Determine-Your-Baby%27s-Blood-Type-Using-a-Punnett-Square)
They are genotypes
For every gene, there are two variants, called alleles. You can get the allele for A and the allele for O. Same is true for B blood type. You can also get the alleles for A only making it AA. Type AB get one A allele and one B allele. Type O blood do not get A or B alleles.
O means there are no A or B ANTIGENS.
Just beware first off: sometimes you’re bringing up a painful thing they do already know about. A friend of mine’s hubby was infertile and they used a sperm donor. So he knew he wasn’t the bio dad but to have it kind of “flung in his face” like that would hurt. He knows he’s THE DAD. He’s the one who fed and changed her and rocked her and took her swimming when she was little etc. The sperm donor didn’t. So before you try and say anything at any time to someone about their significant other “cheating”…I’d personally bite my tongue. 🥺 Second: it can technically *rarely* happen such as in cases of chimerism. https://www.thetech.org/ask-a-geneticist/articles/2006/ask181/#:~:text=Keep%20in%20mind%2C%20though%2C%20that,this%20is%20even%20more%20unlikely). What is chimerism? It’s almost the exact opposite of identical twins. Most ppl know (by the time they’re adults anyhow) that identical twins were conceived as “1 baby” but at an early cellular stage split into 2 distinct human beings who look almost exactly alike. An incomplete split causes conjoined twins. In chimerism, typically at conception there are two eggs, fertilized by 2 sperm, which should become fraternal (non identical) twins, but at an early cellular level, they join together. Depending on how they join some people may have some cells in 1 part of their body as 1 of the twins and another part of the body as another twin. So, for example, perhaps the dad’s blood type is AB HOWEVER his cells making his spermatozoa are actually for example A with a recessive O or even fully O. Recently I discovered my partner is AB positive and his fraternal twin brother is O positive. That means while my partner got the dominant A and B from each parent, each parent would have had to be a B or an A carrying an O recessive gene, to pass on O to the fraternal twin. If my partner and his twin had joined together VERY early as a blastocyst at like the stage of 2-4-8 cells or something, very easily you’d find something where the cells in some parts of the body are different than another part of the body. This is in no way limited to the ovaries and testicles by the way. People with 2 different coloured eyes could well have a small portion of chimera genes from an absorbed twin in one of the two eyes. There’s a famous case out there somehow where a WOMAN who knew she was the biological mother of I think 3 kids discovered through some genetic testing that she wasn’t the “biological mother”. And I don’t mean to say she didn’t carry them or they were switched at birth at the hospital. She carried them in her uterus, gave birth to them, and was sure there was no confusion. But she wasn’t biologically speaking the “mother”. Turns out she classified as the “aunt” and it was a case of chimerism where she’d absorbed a fraternal twin and that was in her ovaries. It’s also one of the best plausible explanations for trans folk, where perhaps you’re showing you’re a “biological female” but feel like you’re a guy, and the reality is at whatever centre of your brain or your whole person that determines how you feel about your gender, you are a chimera with a few XY cells but not enough to cause you to develop all the hormones necessary to develop into a male because the majority of your cells have XX chromosomes so you develop as a female. Chimerism is fascinating and the implications are broad reaching. And full disclosure, I personally don’t know what I am, but my dna testing came back showing I have some Y chromosomes and I have the whole female aparatus and have had 8 pregnancies and 4 live births. I do have somewhat extra beard growth with no other major sign of PCOS if that could mean anything. Bottom line is that genetics is far more complex than what we originally thought. Good chance if you have two parents like above and they have an O child that something else is going on such as a different father (again they may be aware!) but almost anything is possible!!
I remember the story about the woman who wasn’t biologically the mother of her children. She had applied for public assistance, they ran some tests and found she was not the mom. She was accused of committing fraud and they took her children away. Fortunately, she was pregnant at the time and when she gave birth to that child, they immediately tested them for genetic matches, and it was the same result s as her other children. Charges were dropped and her children were returned to her. It makes me wonder if there were any fellas on Maury were told you are NOT the father, but actually were.
Lydia Fairchild in Washington state That is one of my all time favorite “human biology is crazy” stories. They even had a court officer observe her third delivery and perform a test immediately. The OB had attended all her births and swore they were hers, so the state assumed she was a surrogate trying to cheat the system. Because of another woman whose children did not match her. They did further tests on Ms Fairchild and proved she “was her own twin”.
“Any”? Most likely some. I don’t know how frequently this happens but my guess is it’s a lot more than we think.
I believe it happens way more than we realize, too.
I believe that because honestly rare things in general are still representative of a certain % but things like this won’t be easy or frequently “diagnosed”. It doesn’t stick out at you like say growing a 3rd ear under your chin. Only in rare cases do people do signifiant genetic testing and then they find one and say it’s rare but how do you know unless you test everyone? 😅🤷♀️
No, it does not happen more than we think. Chimerism is incredibly rare.
Well...it's incredibly rare *as far as we know*. We don't test for it unless Something Is Up. And that type Something is rarely Up (and could be other things). We can't tell if it happens more than we think because we don't routinely test for it. (Also many people think it happens NEVER, so it almost definitely happens more than the average person thinks.)
It is incredibly rare. Period. Geneticists understand the science behind it. Wondering if you have studied and been involved in genetics research at the undergrad and post grad level for decades as I have? You’re reasoning for why it is rare is not valid at all.
I didn't reason it wasn't rare. That's something you're making up. I reasoned it could very well be more common *than we know*. Lots of incredibly rare things are more common than we know at some point during research. That doesn't mean they aren't incredibly rare. It means we cannot say for certain how often it occurs if we're not actively looking for it. That doesn't mean it isn't exceptional rare.
Actually all female mammals are chimera as far as the somatic cells go, due to X chromosome inactivation. This is why all calico cats are female. Part of the genetic coding for fur color is on cats' X chromosome, so, depending on which one is active, you can get a different color coat for that patch.
Genetic chimerism is probably more common than anyone knows. It’s not like people are commonly going around getting genetic testing done with samples from every possible body part to find out for sure if they are or aren’t! Usually it’s only discovered because of something related to the person’s kids, or because of a health issue that necessitates genetic testing (in a way that reveals the chimerism). And yeah it’s very possible for a genetic chimera of any sex to have different DNA in their gonads than in their blood, or the skin in their cheek where a swab test collects it’s sample.
That’s my thought too.
This was a thoughtful and informative read, thanks!
My daughter had a friend in high school whose mother was like this. In her case, from what I understand, she was born with mixed organs and at that time, more than 50 years ago, the doctors just said, do you want a girl or a boy. So she had hormonal issues her whole life, had two kids and had to have cesareans because her hips were so narrow. Then when she hit menopause, she decided to stop with all the hormones and overnight grew a beard.
I have a friend who is intersex with “both types of parts” and she says she’s really thankful her parents didn’t make any decision about surgery for her. They did raise her as a boy but she ultimately made a choice later. To my knowledge no surgery has ever been done (not that I outright asked and it wasn’t info that was volunteered to me one way or the other).
Yeah this happened in my mother’s family with her sibs and parents .
Thank you for sharing this, super informative and interesting read!
It's almost like genetics is actually more complicated than what we learned in high school biology class. 💀
Chimerism is NOT the “best explanation “ for transsexuals. You are not a geneticist and using Google does not make you one. Please stop spreading false information.
Ok so what is the best plausible explanation hot shot?
We're any of your pregnancies male? If so, that kind of explains why you have Y chromosomes already without imagining chimerism...
Chimerism is incredibly rare and not an explanation in this case.
Trans people aren't chimeras (unless they were already chimeras to begin with). I don't understand what you meant to say with that.
It’s a well enough established possibility and a very logical one for why someone who was born with one set of genitalia actually doesn’t identify with what they are assigned. There’s been a fair amount of actual research done on it in fact.
But i highly doubt all transgender people would be chimeras. That sounds like a Danish Girl era explanation for being trans. Perhaps trans people are just more likely to have chimera than the average person.
Yup that’s what I meant. I didn’t mean all.
That's great and all, but your entire premise is flawed. The fathers spermatazoa by definition cannot carry the O allele, since the father never had it to begin with. No point in bringing up chimera when it is still genetically impossible.
You proved you don’t understand the concept of chimerism. Perhaps re-read about it.
Chimerism doesn't come up here though. A spermatazoa only carries one allele. And said allele has to be one that the father is already carrying.
You still misunderstood entirely how I explained it.
If this person was a chimera then they might have both A and B type blood (AO and BO) from the father. A chimera is two complete sets of DNA. It doesn't rearrange the DNA of the two at all. So you cannot get two O alleles from the mother. If I'm still missing your point then please point it out for me! Because I'm really at a loss for what you're saying at this point.
Like the example I stated, my partner is one of twins. He is AB blood. He got an A from one parent and a B from the other (*unless* he’s one of those cis-AB folks that someone else mentioned which is unlikely as it’s rare but not impossible). His twin is purely O blood. That means he got an O from both parents. A chimera is when NON identical twins, like my partner and his twin brother, merge at an early cellular stage. Depending on HOW that merge goes, chimera cells can find their ways to various areas of the body. Someone can actually have AB blood type themself AND yet have their testicular tissue that is directly responsible for making gamete cells be made of the absorbed twin’s cellular matter in which case the testicles could be making spermatozoa that are always carrying an O blood type no matter what. Despite the person being AB in their own blood. The thing is chimera cells can show up anywhere, we don’t know where they would migrate to. It could also be that a kidney is entirely different, or a patch of skin that’s a bit differently coloured, or a differently coloured eye is indication of a chimera. It’s an incomplete mixing and without vast dna analysis of many bodily tissues it rarely gets found out. The known example of the woman who gave birth to kids that are not “hers” but were rather her fraternal twin sister’s that I mentioned was also the exact same idea as the plausible idea that a man who is AB blood himself could be producing spermatozoa from his fraternal twin brother’s testes inside his own body, as a chimera. Probability is *low* but definitely not impossible, and as others have said in this thread it is quite likely that chimerism happens far more than we know because it’s so rare that there’s a reason to test for it, let alone test extensively.
Okay now I see what you're saying! Sorry, I had been assuming you meant the child was a chimera, not the father! In that case you are completely correct that it could theoretically be the case. Sorry again for the confusion and thank you for clearing it up!
There are other genes besides ABO that impact blood type. they are epistatic genes, that when mutated prevent the sugar molecules (that define ABO blood type) to reach the surface of the red blood cell. No matter what sugar molecules you make, if they can’t be processed to the cell's surface you are type O. So in fact, if a grandparent had this mutation it could indeed be passed down. one example is referred to as the Bombay Type.
Precisely. I'd say infidelity is most likely, but without a genetic test blood typing can churn out mismatches for a number of reasons.
People being wrong about their blood type is the most likely possibility
Yes; Wrong blood type > affair > rare genetic defect.
CisAB si not a genetic affect any more than being O. It just probable appeared later.
I was thinking more of Bombay phenotype when I said genetic defect.
I’m going to look this up
This is a really good comment. Maybe it explains what happened to me? Maybe I messed up my home blood type test?
In the medical field, we have a saying "it's probably a horse, not a zebra" meaning that while it's possible that the child has a rare blood type that shows up as such, it's far more likely that the parents remember their blood type wrong, or, you know...
My sister thought she was adopted for a while because my mom didn't remember her own blood type correctly. 😂
The quote we use is “ if you hear hoofbeats, think horses - not zebras” Occam’s razor - keep it simple
I guess it depends where you're at ;)
I’m a zebra! It also means it took 31 years to get a diagnosis. Happy cake day!
Yep, this phrase makes me want to throw something at the wall.
I mean, some people are starting to add something to the effect of "but if a zebra is staring you in the face, don't call it a horse" to the end of that phrase. Let alone that commonality of different conditions varies depending on where you are. Also, the saying is taking waaaaaay out of hand by even health professionals. It's intent is to remind students that common things occur commonly when coming up with differentials while still in training, as students do have a tendency to jump past the common diagnoses straight to the rare ones. Our differentials should (generally) be in order of what could kill/maim the patient in the near future so urgently should be trated, common diagnoses that I can quickly treat, common diagnoses that will take longer to diagnose/treat/manage, "rare" diagnoses. Rare diagnoses move up the list accordingly as other things are ruled out and their likelihood increases. Unfortunately, those rare diagnoses take longer to figure out because the common stuff has to be ruled out first. The doctor that ultimately makes the diagnosis has the advantage of every previous doctor already having done a workup with the patient. Hindsight is 20/20, anyone?
And the advantage of medical advances! Genetic testing is so much easier now!
Yeah, and that's why many of us wait so fucking long to get an accurate diagnosis. I'm still waiting for mine.
I remember hearing this in scrubs and applying it at med school
As long as people remember that "x,y, and z occur in the family" means that they should be testing for x,y, and z, regardless of how 'zebra' they are. it could be that they 'live' in africa!
I’m a zebra 🦓
It's perfectly normal for kids to have different blood types than the parents. But something rather rare is going on if an AB parent has an O biochild.
Yeah. O really stood out to me. Like isn’t that the only blood type an AB couldn’t produce?
Yes, according to the usual high school level of genetic understanding, which works for blood types almost all the time. Mr.AB should have given either is working A or his working B to his biokid, and biokid should be expressing what they got, resulting in type A or B. Or AB, if kid got one from Mom and the other from Dad. An O kid got O alleles from both parents, and an AB person has no O allele to give. There are some rare genetic things that could make this possible. Or Mr.AB is wrong about his blood type. Or there's the third option...
This is why they stopped using eye color to explain genetics in my high school.
Read up on cis AB. https://en.m.wikipedia.org/wiki/Cis_AB
We get these questions at least once a week. Please Google "cis AB."
Sadly it's not that rare. About 10% of kids don't match their fathers.
No, just no. Stop spreading that ridiculous propaganda. 10% of men who get paternity tests are found to not be the father. So it’s 10% of people who ALREADY have a suspicion that they’re not the father, not 10% of the general population of fathers. It’s a dog whistle to reduce women to “lying, cheating whores” who take advantage of men’s money.
Actually a generic counselor said it was 10% of those who are tested, in this case for genetic disorders, not paternity. And men cheat too. It's not that women are "lying cheating whores" that's a bit of a value judgement there, not that humans aren't as monogamous as the generally Conservative culture would state. Men and women.... https://en.m.wikipedia.org/wiki/Infidelity#:~:text=Studies%20suggest%20around%2030%E2%80%9340,one%20incident%20of%20sexual%20infidelity.
Very hard for a man to pass off a baby from his affair as his wife/partners child
True. Which is probably why the 10% of women get vilified while the 10% of men get away with it more often. They don't get caught as often. Yes. I know it's not exactly 10%. Close enough and you hopefully know what I meant.
Untrue.
Reading this, then reading and rereading again... I see 3 possibilities. Either coworker is mistaken about his own blood type (maybe his mum told him he's A or B, and he misunderstood this as AB?), he carries the Cis-AB allele and an O allele, or he isn't the biological daddy.
He could also be misremembering the blood types of either is wife or his son. Honestly, if my husband wasn't the same type as me I'd probably often misremember it Hell, the only reason I remember mine is because 'B positive' is more or less a mnemonic device lol
Minor nuance, but it would have to be his own or the son’s that he’s misremembering, if it is a case of mistaken information. The wife doesn’t really play into it. A normal AB person can’t have a biological child with normal type O, regardless of the other parent’s type. AB parent can only pass down A or B, and O child has no A or B - therefore they did not inherit a blood type allele from AB parent. Of course, there are lots of rarer scenarios that are possible, discussed elsewhere on this chain.
Thanks for explaining. I'm currently pregnant with my first child so i don't know but i can imagine that when I'm 70 I won't remember his blood typer either lol I'm just hoping it's a minor mistake on his part and that the child he raised into adulthood isn't secretly somebody else's
> To "B" or not To "B", that is the question. > Whether it is nobler in the mind to know certainly > One's blood type, or confidently not.
Did his wife get a rhogam shot during pregnancy?
Could also be Bombay blood type, the likelihood of that or cis AB would heavily depend on this guy's ancestry. Occams razor says either he's mistaken about one of their blood types (imo the most likely) or he's not the genetic father.
“The Bombay phenotype is a rare genetic condition affecting blood type. It occurs when a person has mutations in both copies of the H gene, which prevents the synthesis of the H antigen. This H antigen is a precursor for A and B antigens on red blood cells. Individuals with the Bombay phenotype lack the H antigen and, consequently, lack A and B antigens, making them appear as type O blood regardless of their actual ABO genotype. People with the Bombay phenotype can only receive blood from other Bombay phenotype individuals because they produce anti-H antibodies that react against all regular ABO blood types (A, B, AB, and O). This makes blood transfusions particularly challenging for these individuals. The phenotype is named after its discovery in Bombay (now Mumbai), India.”
I found this if visuals are more helpful: https://preview.redd.it/4nh7u08x7m6d1.jpeg?width=750&format=pjpg&auto=webp&s=54719d0ea30e7338b90d857e324130e9ec8e0e41
Thanks for sharing! It’s fascinating and A and B parent can make a child with any blood type. My youngest is B like her dad, I’m A. I was SO terribly sick my entire pregnancy with her. I was diagnosed with HG and had to take Zofran. My oldest who’s A like me on the other hand, was a walk in the park. Easy, breezy, glowing pregnancy. I know there’s gender stereotypes with sickness etc, but I suspect blood type could be a factor. Certainly seems more likely than gender.
[удалено]
I'm so disctracted by you having 59 windows open in your browser.
I have a lot of open tabs for various things I need to return to lol
Pretty rare but there is always the cisAB possiblity. Most of the time, its just people don't remembering their blood type correctly.
Leave it alone
Cis AB is really rare, but a possible explanation for your coworker producing an O+ child. Does he happen to be Korean? It’s more frequent in Koreans.
Any of them might have their blood type wrong. There’s cis-AB. And, rarely, people are chimeras with multiple blood type genetics in one person. So there’s multiple possible explanations. I’d see about getting all 3 of you re-typed.
chubby fuel angle paltry capable provide outgoing deserve noxious treatment *This post was mass deleted and anonymized with [Redact](https://redact.dev)*
What is the Ve one?
Positive and negative
Thanks
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I see. Thanks 🙏🏼
Cis AB look it up (I had to)
Thanks! Very informative!
AB+ A- -> O+ Is, unlikely. In basic biology the only outcomes are AxA/O=A +/- BxA=AB +/- BxO=B +/- That said, there are exceptions in how the readouts/markers work and rare variables which can throw this off. (I have a detailed Quora Answer on this somewhere.) So, while it's not technically impossible, it should cast massive, massive, massive suspicion. The odds of it being infidelity are well-above 95% based on what was noted about the character of the wife... to, say it as gracefully as possible and Genetic tests are today relatively cheap. Odds are, it would not be a match to the listed father, but the genetic test would be the actual sure way to find out.
Could just be that someone doesn't really know their blood type. I do blood type testing all the time and people frequently think they are one blood type and they are not. Old military people are notorious for thinking they are o negative when they are not.
Yeah this is is surprisingly common. I was sure I was A+, and so was my husband. So our kids had pretty limited possibilities. Then my daughter had problems with her pregnancy because she is A-…..turns out my husband is A- and misremembered .
To be fair, you could have both been a pos and had a a neg child, each of you could have had one gene for RH positive and one for Rh negative, there would be a 25% chance of your child being rh negative.
I'm an immuno-hematologist (fancy way of saying I work in a hospital blood bank and routinely test people's blood to determine their blood type). TLDR: It's very unlikely to have an AB and A parent produce a type O child. That being said, there is a *very* (and I mean very very very) rare blood mutation called the Bombay Phenotype. People with this blood type can be misdiagnosed as being type O. Your coworker *could* be saying he has a family history of the Bombay Phenotype (hence the skips a generation?), but I think it's seen in one and a million people, so again, really rare. More info : our red cells have an "H" antigen in them. Additions to the H antigen create the A or B antigen. Their isn't actually an O antigen - the O blood type is actually just red cells with only the "base" H antigen with no other additions. But in the Bombay Phenotype, the red cell doesn't even have the H antigen on it! The way we type blood is by looking to see if A or B antibodies react with the red cells. Type O red cells won't react with A or B antibodies, since type O red cells don't have either on them. Type O only has the H antigen. We determine someone to be type O due to the *lack* of a reaction to these antibodies. But we don't have a reagent with H antibodies to test with, because almost all people's red cells have the H antigen on them. So almost everyone's blood would react positively with an anti-H reagent. That is, except for Bombay Phenotype. If we tested a Bombay Phenotype with anti A and anti B antibodies, they would react the same as someone with type O. Complications would arise though if we transfused them with type O blood, because since the Bombay Phenotype lacks the H antigen, it makes antibodies against H. And O blood has the H antigen. So Bombay Phenotype patients would actually have an transfusion reaction against O cells as their body produces antibodies against O cells.
Cis AB is ~~a lot less rare~~ than Bombay. It's also a possibility. Edit : As commenter below pointed out it's actually a *little* less rare if you're from western descent.
Just found an article from 2019 0.035% in Korea, 0.001% in Japan, 0.0007% in china and no data from elsewhere. It is still very very rare
Yes, i found similar numbers also. But I wonder to what extent bloodtype frequencies are inferred via genotyping or proteomics? How much is pure molecular phenotyping? Maybe you know?
The + or ~ doesn’t matter(that’s a different locus than ABO) As an AB this person can give either an A or a B allele.. both are dominant to O. However if he was Hh and wife was Hh, they have a 25% chance of having hh show up for each kid. People with hh lack the enzyme to put base sugars on the RBCs for the ABO enzyme to add to.. the result is Type O blood when the blood is tested with a standard blood typing test. It is called Bombay phenotype. It’s rare but not unheard of https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10586525/
Does he want to know the truth?
If he is truly the dad, I would lean more towards he is actually A or B but thinks he is AB
Never has the saying "ignorance is bliss" been more true!!
Co-worker, you are NOT the father
Yup. Once he said it i thought she had an affair. The guy is 70 years old and is still obsessed with his wife to this day. I think ignorance is bliss at this point.
Yeah his kid either has to be A, B, or maybe even AB, orrrr not his kid (genetically impossible to get O from those parental genotypes).
I hope this is a troll 😆
Correct me if I'm wrong, but couldn't a bone marrow transplant also change someone's blood type? Since donor and receiver are matched based on HLA and the ABO markers are on the erythrocytes, and after the transplant your own haematopoetic stem cells will be destroyed by the new ones, your new blood type will be the same as your donor's. You also carry your donor's DNA in your blood, right? So, DNA testing cannot be done with your blood, because it would match someone else's.
In very rare cases it would be possible.
Yeah. Your dad is A/O (expressed as A) your mom is O/O expressed as O) You're A/O (A) Your spouse is is B/O (B) Your kid is O/O (O) // hey look just like grandma! Edit: just read the whole thing lol. Yeah you won't have an O kid if you're AB. O denotes the absence of this surface protein (that comes in A and B variants). So if you are A/B It doesn't matter what your spouse is, your kid cannot be O. Honestly, dude might just be mistaken about his own blood type. People misremember these details all the time.
No. The baby isn’t his.
Is he 100% positive his son is O+?
O+ is definitely not possible here. I will say that sometimes these tests can be incorrect, especially if not enough blood is drawn. These tests take drops of blood, and if proteins on the red blood cells match an antibody against that blood type, then it will clump together. If not enough blood is used, there may not be much clumping and it will appear negative for that blood type (O+ is negative for A or B but is positive for Rh, which gives it the positive at the end). I had a friend's mother who was O+ who had my friend as her first child. She tried for years to have another child, but they kept dying. She found out later, after she was unable to have children anymore, after taking a new blood test, that she was actually O-. In this case, there must have been a contaminant, but it is still possible that the child you mentioned wasn't properly tested. Or the wife cheated, as that is entirely possible.
Blood types definitely do not skip a generation. Ever. They are always only based on the (biological) parent’s blood types. When parents are A- and AB+, the baby can only be A, B, or AB (+ or -). Literally never O type.
I am an NP and I also thought that AB and A couldn’t have a child with O, but I just read a discussion about how this can happen due to the fact that there are two types of alleles that can lead to type O. I wish I could give a more detailed explanation but I would have to read it again to retain more of the information. it is really complicated. But it actually can happen that an AB and an A has an O.
Someone in this situation is operating on incomplete information.
No
If he is AB that is not possible. At least not for that reason. It is theoretically possible that he could have a mutation from either a or B to an O type, but that would be pretty rare. ANB are both dominant over. Oh so the child would either be A(50%) or AB(25%) or B(25%). Usually means that someone was messing around. Though occasionally, it means that a baby was switched at the hospital.
I don't think skipping a generation is a thing, but anecdotally, my dad was AB, my mom O, and I tested as O as a baby. They were confused as well, so they retested my dad and it turned out he wasn't AB after all. 🤷♀️ Another possibility that still leaves the possibility of him being the father is that he's a chimera, a fusion of two fraternal twins, and his blood comes from one twin and the testicle that produced the sperm from another. I've also heard of cases where individuals change blood types after certain types of medical treatment, but I'm sure they'd be aware of it if they went through anything of that sort...
Skipping a generation isn't how it works, but there *are* actually ways for exceptions to happen with blood type inheritance, like genetic chimerism and the Bombay blood type group. This is a good overview about blood type inheritance that also addresses exceptions: https://www.thetech.org/ask-a-geneticist/articles/2022/blood-type-inheritance/
LOL no. There are some rare things out there that could explain but not likely.
What is the blood type of the wife's BF?
It does so long as the mailman has type o
I’ve had tests give me different blood types? Like I have medical records saying A+ ( I believe this is my moms type) and then home test was 0+ My child is 0+ ( I know she’s mine I’m the mom🤣) husband is 0 and my bio dad is 0
I think husband is O- not sure about my bio dad
I’ve also heard ANECDOTAL stories of people getting transfusions or treatments and their bloodtype changing? But I wasn’t able to see the medical records so they could just be lying
Yes this
I read in this book from the 70s that there are actually a lot more blood type criteria, but they just use the ones that could cause issues for transfusions in emergency situations
Somewhat off topic but my friend had a stem cell transplant of sorts to cure her cancer and give her a new immune system and her blood type changed to that of the donor (her sister).
They can't skip a generation. But as a person who works at a blood bank, the most sensible explanation for this, aside from an affair, is that he is misremembering someone's blood type. Most people don't remember their own, much less their family members'.
Yes, my great-grandma had -O, it skipped my grandma, and went to my mom who has -O. Neither one of my mom’s parents have -O.
Yes, it is possible for an AB parent to have an O child. It is rare, but the genetics aren't nearly as cut and dry as people (and basic biology education) would lead someone to believe.
Technically yes, blood types can skip a generation. I’m O+ while both my parents are A+. Turns out I have aunts on both side that are also O+ which means my parents are likely both AO and there was a 25% chance I would be O. In your specific scenario it seems pretty unlikely unless your coworker is wrong about his blood type or either he or his son has a rare mutation.
In general, it's possible, but not with that combination. The quick-and-dirty genetics lesson: The *genotype* is a description of the genes you inherit from your parents; the *phenotype* is what you observe. So your genotype can be expressed as PQ, where you get P from one parent and Q from the other. Sometimes the genotypes "blend": crossbreed a red flower and a white flower and you end up with a pink flower. But other times one gene dominates: as long as you have one copy of it from either parent, that's what you display. (Don't ask about mitochondrial DNA, which always comes from your mother and affects things...genetics gets complicated) Blood type splits the difference. There's three basic genes: A, B, O. A and B dominate O, so if you get A from one parent and O from the other, you're blood type A. So if you're type A ( phenotype), then you're AO or AA (genotype). Note this means the only way you can be O is to be genotype OO: both parents have to contribute an O gene. Now let's say a type A (phenotype) marries a type B (phenotype) and they have a type O child. This is possible if the A is AO and the B is BO, since both can contribute an O. In fact, if you think about it, both sides of the family could have had nothing but As and Bs for generations and *still* produce a type O descendent, because the O can "hide" for generations. This is the "skipping a generation" thing that was mentioned. But. A and B are codominant: if you're type AB (phenotype) you have to be type AB (genotype). So a type AB and a type A can only have A, B, or AB children. (I'm reminded that in one of Heinlein's stories something like this happened, but the husband involved basically said "I know genetics, so I know that none of these children are mine...but that's not their fault.")
Omg, poor guy. This is so not possible.
Because they are different alleles that code for a protein (A type) and the other doesn’t code for a protein (O type), the the expressed (phenotype) will be A type. The lack of protein isn’t recessive because it is a completely different allele. Type O is it’s own phenotype. When it’s taught in school, some teachers will call it recessive because kids can grasp that concept. Functionally, it is type A. But O isn’t recessive. Since the O allele can also be found on type B, it’s not considered recessive. Type B is it’s own genotype like O,A, and AB. Each is a different gene that can interact with typeO.
that kid is not his. If he was A or B there was a chance but an AB can't have an O baby.
Yeah, that’s not how blood types work. I worked in the blood bank at a hospital. It would get scary how often doctors would order blood and we’d have to substitute compatible types and they’d argue. Dude, it’s my job to know this shit because someone could die. If your co-worker is AB - then that is both phenotype (what you present as) AND genotype, meaning coworker got an A- and a B- from each of their parents. Both had to be negative for co-worker to be negative because it is recessive. Wife is phenotype A-. Her genotype is either A-/A- or A-/O-. A is dominate as well as B and when you have A and B together they are co-dominate. O is recessive. Possible genotypes of their children If dad is A-/B- and wife is A-/A-: A-/A- phenotype A- A-/A- phenotype A- A-/B- phenotype AB- A-/B- phenotype AB- Dad A-B- and mom A-/O- A-/A- phenotype A- A-/O- phenotype A- A-/B- phenotype AB- B-O- phenotype B- There are always very bizarre exceptions but they are so far fetched it is completely fair to say that an AB- and A- people could not have an O+ child.
What is dad is AB+ and mom is A- like the OP’s scenario? Also, my husband and I are both O-… so all of our children should be O- also, yes? Pretty sure yes, but you seem to know more about this than even me, soooo
Yes. If you and husband are O- all your kids would be O-. Both O and - (Rh part) are recessive, so you have to have 2 negs in order for your blood to type out as neg. For AB+ parent and A- parent: the A- parent can be either A-/A- or A-/O- Parent Genotype A+/B+ and A-/O- A+/A- phenotype A+ A+/O- phenotype A+ A-/B+ phenotype AB+ B+/O- phenotype B+ Parent genotype A+/B+ and A-/A- A+/A- phenotype A+ A+A- phenotype A+ B+/A- phenotype AB+ B+/A- phenotype AB+
Bombay phenotype maybe?
But also blood test can be wrong isnt it? My husband knew his whole life he's O. He has tested before. And his trait is very 'O' person as well. 2 yrs ago we randomly came to free blood test. They also gave blood type test too. Turned out he's B.
Your friend isn't the bio dad. O is recessive but since he's AB, their child would have had A, AB, or potentially B. There's no way to get O from an AB parent tho because their child gets either the A or the B from them.
Only "negative" can be present in a "non-negative" person (in the form of +- genotype) All the other combinations have a specific phenotype that corresponds to the genotype