I have AB+ blood and my mom is type O — both confirmed by hospital tests during my brain surgery. How is that possible?

r/

When I was younger, I had brain surgery, and both my mom and I had our blood types confirmed by the hospital. She’s O, and I’m AB+. I’ve looked into rare cases like cis-AB, but that doesn’t seem to explain it. Could there be a medical or genetic reason for this? New user pass phrase: I genuinely don’t know the answer

Comments

  1. Kind_Drawing8349 Avatar

    It’s simple: your father has AB+

  2. WrappedInLinen Avatar

    They tried to tell you about it a long time ago, but just couldn’t find the right moment. Just be grateful that they gave you family when you needed one. The details aren’t important.

  3. rosenposen Avatar

    If she’s your biological mother, maybe she has chimerism? Do you know what her parents’ blood types are?
    But also are you sure she’s your biological mother?

  4. Manhunting_Boomrat Avatar

    Swapped at birth, calling it now

  5. notthinkinghard Avatar

    Cis-AB does literally explain it. I’m not sure what you meant there.

  6. pinkrobotlala Avatar

    Donor conceived?

  7. sshipway Avatar

    * Adopted
    * Accidentally swapped at the hospital
    * Mother has chimerism – this is rare, but definitely not unheard of – and her ovaries are from a different DNA than her blood
    * Donor eggs due to fertility issues
    * Original blood typing lab results were wrong and you are not O-/AB+ at all

    Basically, it is not genetically possible for type O to naturally have an AB+ child.

    (edit: fix typo and add additional possibility from u/Sehtal )

  8. umbratwo Avatar

    Just have both of you retake the test. I have medical records saying I was O neg as a child, recent tests show O+. There’s always mix ups by tired lab technicians around the world.

  9. BugsArePeopleToo Avatar

    There’s plenty of ways for this to happen.

    Her phenotype could be O, but her genotype could be A or B.

    She could have chimerism.

    Cis-AB would also explain it

    Or, you may not be generically related to your mother.

  10. Histrix- Avatar

    Time for a Myheritage dna test!

  11. _iamsugar_ Avatar

    I saw a video few months ago that transferring bone marrow cause a change of blood type, but idk in what cases or if only some blood types are used. But girl that talked about i had it changed to O.

  12. InflationCold3591 Avatar

    She is not your biological mother. Sorry.

  13. beamerpook Avatar

    Ya something is not adding up there. Theoretically it’s possible that either you or your mom have an ultra rare medical condition, but it’s most likely (99%)that it’s not your biological mother

  14. takesthebiscuit Avatar

    I’m looking forward to this conclusion on /bestofredditupdates

  15. MiceAreTiny Avatar

    There can be more going on, but most likely, your mother is not your biological mother.

    It can be that your mother is a chimera and her blood cell lineage is genetically distinct from her egg cells. It is possible that your mother is phenotypic O, but genotypic A and/or B, e.g. H-antigen.

    Was your mother (or you) ever treated for leukemia? Did one of you ever get a bone marrow transfusion (as receipient)?

    And,… what is your father’s blood type?

  16. LopsidedPotatoFarmer Avatar

    Is either a medical rarity or she is not your bio mum OR the hospital gave you the wrong results (I would recheck to update your file)

  17. hhfugrr3 Avatar

    So a lot of people are talking about adoption, mix ups etc. But, maybe you’re a secret military experiment that was grown in a lab and you will be activated when the moment is right. I mean it’s not impossible. Have you considered asking your mum about it or maybe the military’s genetic programming prevents you discussing the issue with her!?

  18. KarenWalkerwannabe Avatar

    There are some medications and illnesses that can change your blood type. I am A+ but before every major surgery I’ve had they still type my blood. I always ask why and they give me the same answer.

  19. DanishWonder Avatar

    Do an Ancestry DNA test.

  20. get_to_ele Avatar

    Cis-AB would explain it. You dismiss it pretty casually, even though you do not report that they tested.

    Do you have some other reasons (other test results, appearance, other clues) to suspect you’re adopted or born via IVF egg donor, and just don’t want to explicitly bring it?

    https://academic.oup.com/labmed/article-abstract/37/1/37/2657444?redirectedFrom=PDF#google_vignette

  21. C_Brachyrhynchos Avatar

    Mom could have an unusual A subtype that didn’t react with the test method used for her type.

  22. ScienceAndGames Avatar

    Few possibilities,

    1. One or both blood tests are incorrect, lab mix ups happen.
    2. You mentioned Cis AB, that could explain it but your dad would have to be the one who had it and passed it onto you.
    3. Your mother has the Bombay phenotype meaning that she has the A or B allele but there’s an error in an earlier part of the synthesis pathway that stops the antigens from being produced. In that case she’s not actually O but blood tests miss that because they don’t test for O directly, they test for A and B and if neither if found it’s labelled O.
    4. Certain medical conditions can mess with blood type tests or even temporarily change your blood type, lupus for example. Edit: Also bone marrow transplants will change your blood type to the donor’s.
    5. Your mother could be a chimera with different DNA in her reproductive cells and blood producing cells.
    6. You could be adopted, swapped at birth, actually a relatives child who was taken in, etc.
    7. You could be a case of a mixed up egg used in IVF.

    Edit 2: 8. Actually it could technically also be a spontaneous mutation, if I remember correctly there’s only a single base pair difference between the A and O alleles so while extraordinarily rare, an O could theoretically mutate into an A.

  23. Aggravating_Branch86 Avatar

    Ya know, my mom is O+, dad is B-, and I never considered it odd that I’m AB-. I know for a fact that mom is O+ and I’m at least a A/B/AB negative type, because we have record of my being born jaundiced due to abo and rh incompatibility. Maybe I’ll have to look into confirming my blood type

  24. Green-Dragon-14 Avatar

    Maube your dad has AB+ blood type?

  25. stevesuede Avatar

    Switched at birth it has happened. DNA test?

  26. Carlpanzram1916 Avatar

    Your options are 1: one of you was typed wrong at the clinic. Happens more often than you might think. This is why the patient receiving the blood gets typed and screened twice before they get blood. 2: your mom is not your mom. We’re you an IVF baby by chance?

  27. Tiana_frogprincess Avatar

    The most likely explanation is that one of your test results are wrong. If not the chances are that she’s not your biological mom, that is probably more likely than her being ABO (unless she’s Asian)

  28. Nani_the_F__k Avatar

    What’s your father’s blood type? 

  29. logaruski73 Avatar

    Your father was AB. Your mother is O. You are AB. I’m not sure I understand why this is even a question. The negative/positive is irrelevant as it is independent of the parents. In addition blood type genetics is not as simple as we were led to believe in high school. This is still an over simplification but it contains good basic information. https://www.thetech.org/ask-a-geneticist/articles/2006/ask199/

  30. JadeMcG Avatar

    I am O- and my kid is AB+ and we’ve both had DNA tests done for health/genetic reasons – no doubt my kid.

  31. haraldone Avatar

    My mother is O and I’m AB+

  32. shaggyyguy Avatar

    It’s not super common, but look up Bombay phenotype. A person can be genetically A/B/AB but lack the H antigen that is the precursor to A and B antigens, which means they look like type O.

  33. Ronville Avatar

    I suspect bad memory is the culprit. I gave blood two years ago, was told my blood type (B I think) but I’ve already moved to unsure. Just wasn’t important enough to write down or remember. Wouldn’t be shocked if I’m A or O. Hospital will type you before transfusion. Shrug.

  34. motherofhellions Avatar

    My oldest’s blood type is A+, I’m O+. My younger two are O- and O+. Because my blood type is only half the puzzle. My oldest’s father is probably type A (never asked him, terrible situation), while my husband and the father of my younger two is O-. So, what’s the blood type of your other DNA contributor?

  35. otterstew Avatar

    In addition to the far most likely suspects: prior lab error, switched at birth or adopted, chimerism/mosaicism …

    If you or your mother has received a number blood transfusions during your lifetime, it can change your blood type by introducing new antibodies.

    Or if you or your mother have even been a stem cell or bone marrow transplant recipient. In the same realm, leukemia can also change blood type.

  36. Panda-Head Avatar

    If you have stuff like birth certificates to back you up, hospital mixed up your test results. I would get a type card kit on ebay. If you have access to a diabetic’s pin-in-a-pen type of pricker use that instead of the blade-in-a-box ones.

  37. Nightowl11111 Avatar

    Your father is AB+. O is not the presence of a HLA, it is the absence of either, so you could have gotten both from your father. It’s Cis-AB like you mentioned.

  38. dracapis Avatar

    r/genetics might be more suited to answer this, if you’re sure of the results

  39. Fast_Ant5324 Avatar

    If dad is type B this is entirely possible

  40. Cherrygasp Avatar

    Either those blood tests were wrong or u got a wild ass story behind ur birth bec no way u get AB from an O mom, she literally don’t carry A or B to pass on. i’d fr get retested or ask some deep questions lol.

  41. Astute_Primate Avatar

    Ok, here’s a scenario that we used to think was exceedingly rare, but is looking more common the more we need to use DNA in the course of medical treatments. Your mom may be a chimera. Like, you know how identical twins start out as one embryo that splits in two early in development? The reverse is also possible. Two embryos can fuse into one resulting in one person with two genomes. Your mom may have been the result of two genetically distinct embryos (fraternal twins) that fused very early in development. When this happens, the cells from the two embryos tend to flock together and form individual systems rather than dispersing themselves uniformly throughout the body. They’re not even found in equal proportion. So your mom’s reproductive system may have had a different genome than some of the other systems in her body. If her erythrocytes (the cells destined to become red blood cells) are type O that’s what they’d find in the blood test, and because O- blood is highly unlikely to illicit an immune response, she could go her whole life without ever knowing unless something extraordinary happens, like the whole fam needs to be blood typed because someone’s having major surgery and they need a compatible donor on standby in case they need an emergency blood or tissue donor.

  42. surfacinglilt Avatar

    My brother and I both have different blood types to our mum – she’s A something, we’re both O something like our dad. It’s not common (and more dangerous if the baby is male), but it’s not unheard of. We both look like her/her side as well as our dad’s side, we’ve been tested and all that and we’re deffo hers. Sometimes it just happens.

  43. AlternativeLie9486 Avatar

    You have a father…

  44. Aetheliant Avatar

    Could be a donor IVF egg! My mom did that because her eggs didnt work. So me and my sister have my dads genes and not my moms

  45. EmEmAndEye Avatar

    There was a case where the mom’s genes didn’t match her several kids’. The state took the kids away, despite doctors and everyone testifying that the kids were hers.

    Turned out, she had absorbed a non-identical twin sister in-utero. The mom’s reproductive organs were from the absorbed sister so the kids were genetically not the mom’s at all. The mom was the aunt to her own kids!

    Scientists were astounded that the reproductive parts were able to coexist with the mom perfectly.

    Anywho, there are many ways that your situation could’ve come to pass with your mom having done nothing immoral, illegal, or wrong in any way.

    Please, come back and let us know when you find out to reason(s).

  46. gundam2017 Avatar

    Because blood types aren’t black and white. My dad was O+ mom is O-, I’m A-, sisters are a mix of A. Mt husband is O+, both of my daughters are O+.

  47. Angery_Roastbeef Avatar

    You can buy blood typing kits cheap on Amazon. If that comes up with the same, get a 23andMe, or similar.

  48. lastcall123 Avatar

    ockham’s razor: you’re adopted