The Birds and The Bees and Blood Types

We'll say this is a hypothetical question.

Parent 1 has blood type 'O'
Parent 2 has blood type 'AB'

Can this couple give birth to an 'O+' baby ?

Both parent 1 and 2 have passed away. How would I go about confirming that parent 1 and parent 2 are that kid's parents?

Asking on the off-chance that there's a geneticist among us or that someone has these blood types in the family.



I wish I could talk to my wife about this but she is grieving the death of her father-in-law and is already a little worried about me and how I'm dealing with the situation. I didn't want to give her more cause for concern.So thank you for letting me pick your brain and use you as a sounding board. Much appreciated.

I've thought long and hard and this is what I've concluded. I'm angry and I resent this man for not being there for me when I was a child, for coming back into my life and making me like him and trust him, knowing that he may not be my father and then dropping this bombshell before dying on me. I owe him nothing . Any sense of filial duty I may have felt towards him when he was alive was misguided. I refuse to honour his wishes.I don't want a single cent of his money. They can cremate his 740k with him, for all I care. Perhaps I'm being immature, and the anger will most certainly fade away after a while, but I know for certain that I won't regret this decision.

As for getting a paternity test ,I've decided not to do it. I don't want to hurt those he's left behind. My children are grieving the man they believe is their grandfather and there's a little girl who will grow up without a father. I would not want to deprive her of her half-brother, her half-niece and nephews. She loves us and we love her. Whether we're blood-related or not is of no consequence to me.

The only downside I can see, is that without the DNA test, I cannot rule out that he was my father and with his family history , that I have a 1 in 2 chance of getting prostrate cancer. I'm just going to have to keep doing the tests regularly. In the grand scheme of things, this is just a minor inconvenience, if I may call having a man insert their gloved finger inside of me on a regular basis, a minor inconvenience 😒


  • +1

    In most cases, the child will have type A or type B blood.

    • Thanks. So impossible unless one of the parent is a chimera?

  • +1

    According to the charts this should not be possible:

  • +8

    No - Parent 1 donates a gene with no antigens (O) and the other parent donates a gene with either A or B antigens. The + relates to Rhesus factor with is another attribute, but not specified for the parents in above info. Both would need to be Rhesus negative to have a Rhesus negative baby, so wont make much difference to you enquiries. Please take note, the blood types originally done can be in error - when I took genetics at uni we all did our own blood type test. My parents were both O+ according to their medical records. After 5 tests I was A+ every time, so uni sent it off for a professional lab results whilst my parents squirmed. Found out my paternal grandmother was also A+, dad was retested and found to be A+ too. The milkman sighed with serious relief!

    If you have hair or a tooth from the AB parent you could get a DNA test done for determine their relationship to children.

    • Thank you . What are your thoughts on chimerism or even cis-ab? Could either of these explain that their child was born with 'O' blood type?

      Edit: Parent 2 died from cancer following a year long treatment. I might be able to access his medical records. Would these contain his blood type and notes regarding either chimerism or cis-AB?

      • +2

        Could but the chances would be low, Chimerism is usually an attribute from multiple birth, or multiple birth errors (absorption of one embryo by other in womb) so if there are cases of multiple birth in the family it could be considered. CisAB is very rare, but must be considered if there is a potential Cis ABO phentoype in a parent. I am not an expert on the one, but it was my understanding the the CisAB gene donation is most likely going to confer an antigen of some type, and the CisAB is dominant so the chances of the parent donating an O allele is unlikely. Genetic testing is the best method for determining parentage but HLA antigen testing can also be interesting if the AB parent ever had that testing done during lifetime. Good luck!

        • I have twins and my 3rd child has sectoral heterochromia ( a la Henry Cavill) which is becoming less noticeable as he is getting older. So chimerism is a possibility :)

      • +2

        Sorry - didnt see the edit. Yes, definitely have blood type but it isnt likely blood type checks would be that indepth past phenotype unless there was a reason to dig deeper for blood matches (organ donation etc - this would also provide HLA info as I referred to in the other comment). But - unless you ask you wont know, so I would get what you can. I am sorry for your loss.

        • +1

          Thank you. He wasn't there when I was a child. Although he did try to make amends but I was already an adult by then and didn't need a father. I considered him more a friend. I'm sad at his passing but not inconsolably so.

          I'm more grappling with an ethical dilemma : he left me quite a substantial sum of money which I believe I am not ethically entitled to if I'm not his biological child.

          • @DisabledUser102420: Not often one reads of such ethics - I hope for CisAB for you! If there are other children, CisAB is dominant so highly likely they would show it. Can you steal some blood or DNA and get a test done to ease your mind quietly?

            • @Tanzere: My half-sister is a minor and lives overseas. We couldn't look any different: I take after my mother who is Irish and she takes after hers who is Japanese :) And there's a 30 year gap between us! It is a weird relationship but we are fond of each other. She also has a close bond with my kids.

              Her mother would rather I keep my share of the inheritance and that I "honour the wish of my late father". There's also an expectation that I will look after my half-sister if something was to happen to her mother. She is unlikely to approve any test that may invalidate my relationship to her child.

              To answer your question…not really:(

            • @Tanzere: If I were to get the mother's approval, where/how do I go about getting the test done?

              • +1

                @DisabledUser102420: Any lab advertising paternity testing will test for you, they should be able to test from a check swab so not invasive - I guess the question more about what you want from the result. There is a point to testing your potential prostate cancer risk. I really like Pointscrazy's POI below just for my 2 cents worth. Personally I would not use Ancestry or similar. Good luck, I hope you find the answers you need.

                • @Tanzere: Thank you :) My psa density was 0.18 ng/ml/cc last time I got checked. So not too concerned about prostrate cancer atm.

          • @DisabledUser102420: Him treating you as his child and passing you his wealth is not an ethical problem unless you knowingly made the now deceased person believe something you know to be untrue.

            • @tshow:

              Him treating you as his child

              He didn't. My original birth certificate had 'father unknown' . I was very much an unwanted child and was sent to Australia to be raised by my maternal grandparents. I was 18 the first time I met him in person. The cynical part of me can't help but think that he reached out to me because he saw some potential there. He tried to get me to follow in his footsteps. Thankfully, I didn't.

              passing you his wealth is not an ethical problem

              This money should go to his family. If I'm not related to him , then I want none of it.

              unless you knowingly made the now deceased person believe something you know to be untrue.

              I didn't. He did. He knew that he was unlikely to be my father but he never said anything to me. Not until the very bitter end. Why?

          • +1

            @DisabledUser102420: my parents weren't my birth parents. My sister was biological. Neither of us cared when it came to the inheritance as long as we split it evenly.

            Take the money. Buy your sister a meal or a holiday.

            • @brad1-8tsi:

              Buy your sister a meal or a holiday

              Disney world followed by a meal at KFC in exchange for giving me $720k?! Doesn't seem like a fair exchange to me. Although I'm sure she would readily agree to it :) My half-sister is 5 .

              • @DisabledUser102420: Honour someone's wishes especially it is a gift to you.

                Dishonouring it doesn't make you a martyr. In fact, I would call it ungrateful.

                In certain (and I'm sure it's in fact many) cultures, being ungrateful and dishonouring a will are both individually a very big no no.

                • +1

                  @tshow: The inheritance comes with strings attached. There's the expectation that I will be a father-figure to my half-sister and raise her as my own if something were to happen to her mother.

                  Normally, I wouldn't have a problem with that. I take my responsibilities seriously and I'm very fond of this little girl ( and her mother) . However, this man was never there for me; he let people he'd never met raise me. He may not even be my biological father and he knew it. And yet, he expects me to raise his child as my own because Maya is the apple of his eyes and he couldn't bear the thought of her growing up without a father. It hurts a little that he had the capacity to feel so much paternal love for someone but not for me.

                  The money is a poisoned gift. The thought of it is making me angry and resentful and I don't want it.

                  • @DisabledUser102420: I'd suggest you chat to a counselor or psychologist about how you feel. It will help you put things into perspective.

                    I had a lot of negative issues regarding my father after he died in 2016. Some were big and others quite petty. eg: He had a large yearly income from his investments (his capital was growing every year) but never took the extended family out for a meal even though he enjoyed our company and we all get on well. His Xmas present for the grandchildren was $20.
                    A few sessions with a counselor and I saw it from his point of view. He was born the year before The Great Depression and was quite poor. Then his teen years were during the austerity of WW2. Then he had ill health and was always trying to save money so that Mum and us kids wouldn't be destitute if he died. Medical advances kept him alive and he outlived Mum but saving and frugality had become a habit so he couldn't bring himself to spend it.
                    Our inheritance meant that my Sister could retire at 58 as she has poor health and that I could buy a nice apartment even though I'd just taken a huge financial hit in a divorce.

                    On the plus side, it did change my attitude to money and I tend to spend more these days on my kids and doing fun things when we are together.

                    • @brad1-8tsi: I've never had any issues with my father before. I did have counselling to help heal my relationship with my mother but in the end, we agreed that I was better off without her in my life. I gave away all the money I've inherited from her.
                      According to my wife, who used to be a social worker,the anger /resentment that I'm currently experiencing is part of the grieving process.

                      • +1

                        @DisabledUser102420: I would agree with what your wife is saying. Modified Kubler-Ross 7 stages of grief. Just try and ride it out and don't make rash decisions.

                        I find talking to others helps me as I'm not very good at thinking outside the box and am a bit "black & white".

                • @tshow:

                  Honour someone's wishes especially it is a gift to you.
                  Dishonouring it doesn't make you a martyr. In fact, I would call it ungrateful.

                  And I would call it giving the middle finger to someone who was never there for me and lied to me for all of my adult life.

      • +2

        Can I ask what kind of cancer? If your dad had a bone marrow transplant that could also change his blood group (eg: he may have been group AB when he passed away, but been a totally different blood group before the bone marrow transplant)

        • Prostate cancer. So did his brother. There could be a silver lining to finding out that he's not my biological father…

          Ps: My father was a gynaecologist and would have known that our blood types may have been incompatible. He only told me about it AFTER he found out he had terminal cancer.

    • I’m A- and my husband is O+. Both my children are negative blood groups.
      This is due to recessive traits.

  • +5

    Saw birds and the bees in the title, came and was disappointed :(.

    • +1

      Lol! sorry

    • +3

      The last part of your sentence appears to be a contradiction.

      • +1

        I am full of contradictions today.

    • +2

      I would be too if a title did that to me.

    • +1

      Who was disappointed?

      • +1

        People who don't understand genetics? Maybe I should add the following:

        TL;DR : Incompatible blood types reveals that Darth Vader may have been lying!


  • OP….does this confirm your child is not yours?

    • +4

      Nope.The question was relating to my parentage, not to that of my children. Although since you've brought this up, my youngest with his blue-brown eye does look a lot more like Henry Cavill than me. Does anyone know if Henry Cavill was in Melbourne around Mother's day 2016? ;)

  • +3

    Honour his wishes and accept it.

    I wouldn't be messing with things or even questioning it after his passing unless you really wanna screw with the family's thoughts at an already emotional time

    • But wouldn't you want to know?

      • Not at that point, no

        • My mother was a fair-headed, blue-green-eyed lass. My father was a young ,black South African doctor. They met during the anti-apartheid struggle and made me.I'm bi-racial. This is part of my identity. Part of the reason I fell so hard for the woman who became my wife ( other than she's completely stunning).She's from Mauritius and is therefore African. African like my father. African like half of me .

          Now, if this man is not my biological father, who am I ? Do I still have roots in Africa? I am still bi-racial? I feel like Peter Parker, if he woke up one day and realised that Spider-man was never a real thing; it was just him playing dress-up : lost and bereft :(

    • Honour his wishes and accept it.


      I wouldn't be messing with things or even questioning it after his passing unless you really wanna screw with the family's thoughts at an already emotional time

      I agree that would be unnecessarily cruel and I'm not a cruel man. Quite the opposite actually.

  • Buy your sister a “gift” of an kit. If. You also complete kit. If you have your settings right and she is a relative she will come up as a potential relative in their database. Otherwise you may find your natural father in their database.

    • My half-sister is 5 and lives in Japan. I was born in South Africa 36 years ago. Unlikely that this would work.

  • +2

    Although I'm guessing these ancestory DNA kits can get things wrong, they might share some interesting light on your ancestral roots so for your own interest you might like to take one.

    I'm only speculating here but I think the man who has left you money in his Will has chosen you as the right "person" to give the money to rather than you as a descendant/next of kin. I think he trusts you to do the right thing with the money. He knows you are fond of the 5 year old and as a person would do all you could to help her regardless of whether you had the inheritance money or not. Accepting the money will help make sure it is used in a positive way.

    I can understand that this is a difficult situation. I'm not a scientist so I can't give you an accurate answer to the question posed above. I'm glad you had a chance to grow up without having to live under the racial laws of South Africa of the time.

    Good luck with your thoughts.

    • Thank you :) Her name is Amaya.

      • Thank you.

  • +1

    You might benefit from some genetic counselling.

    • Regarding my risks of getting prostrate cancer? I've been told if he's my father, my risks increases 5-fold and need to get regular check-ups.

      Other than that, I'm healthy and a regular blood donor.

  • It seems that it's not a secret that your father may not be your biological father. Could you reach out to your father's extended family for DNA tests, eg his siblings? Have you spoken to your mums siblings to see if they think he was your biological dad? If he isn't, what is the next step for you? I can't help feeling that the whole situation is about a lot more than the inheritance. Your father left you the inheritance (albeit with strings attached) knowing you may not be his biological son, and your half-sisters mother knows this too, and wants you to take it. This is such an unusual situation. I wish you luck.

    • +2

      My father was in love with my mother. He wanted to believe that she loved him too. I don't know if that was the case. When she fell pregnant, he begged her to run away with him to a place where their love ( and their child) wouldn't be a crime. So there was a time when he thought I was his.

      I remember telling him proudly one day that I'd donated blood and that I was a 'universal blood donor'. I would have been 18-19 at the time. He was an ob/gyn , he would have known what that meant. It's hard to remember what his reaction to my announcement was but I vaguely recall him asking me if I had my mother's contact number. I didn't. Neither did my grandparents.

      I believe he had his doubts about my paternity from that day onwards and he may have shared those doubts with his new partner. He only told me about it shortly before he passed on. So yes, it was a secret.

      My father had a brother who died about 10 years ago from prostate cancer. I believe he was gay but it was all very hush-hush. He had no children.No other siblings afaik.

      My mother was an only child. She took up social causes very early in life more I believe as an excuse to leave home and travel the world than a real desire to make it a better place. So no siblings and no close friends. She did leave a lot of broken men in her wake though. I did speak to 3 of her ex-lovers ( and my father), trying to get an insight into who she was as a person shortly after her funeral. You'd think she was Helen-of-Troye-meet-mother-theresa from the way they spoke of her.They only saw what she wanted them to see.

      No idea what my next step is. Luckily , we're in a position where we don't need that money.That being said, my father's partner is in remission from breast cancer. If something was to happen to her, I couldn't in good conscience , not take Maya in , whether she is my half-sister or not.

  • +2

    Two parts, JJB.

    Sympathies for both your loss and for the confusion.
    The multiplicity of those.

    This thread, at least in part, explains your current ozb bender…
    You are under some stress.

    Perhaps I'm being immature and the anger will most certainly fade away after a while but I know that I won't regret this decision.

    Perhaps just a little; it might, and you may.
    Family complications of one sort or other, not uncommon. You have / had, a particular batch. Might as well just go with ebb and flow of it at this point.

    Now, if this man is not my biological father, who am I ? Do I still have roots in Africa?

    With or without having certainty as relates your Dad, you are an interesting mix and leading a good and interesting life. Fairly likely that African heritage just as real as perceived by you, prior. Various things to be significantly happy about as relates life as turned out.

    You have potential beyond yourself to do good things with any money inherited/accepted, and can also give reassurance to half-sister's Mum, just generally, and also specifically if needing that. It appears that you have decided to do this, regardless of any decision relating to money. This is good.

    I'm not quite sure why you didn't initially embrace the potential good in reassuring aspect, given relationships established, and especially given the somewhat abstract nature of concern, at present. Unless Mum's breast cancer remission very tenuous on basis of original diagnosis and treatment involved.
    Barring consumption from a bad batch of Matcha Tea Kit Kats, or some dodgily-prepared Fugu, a reasonable chance daughter will reach adulthood and mother live to see that.

    Maybe at least some of that money mentioned, if accepted, and in fullness of time, used to good effect in Mauritius. HDI still only greenish, despite any magical powers exerted by way of ready availability, of strawberry guavas…

    Your MaybeDad, made gesture based only partly on guilt. He will variously through the years, have convinced himself that you were just better off, left be, to be raised by the good people who did raise you. Crossover to love and with real feelings of loss, with that, for him. Don't doubt that, even allowing for everything else.

    Right now, I'm going to write the comment I came on to write (about a bloody light bulb) then I'm going to bed.

    More tomorrow, today your time.


    • +1

      Thank you Dne :)

      Two things (because you like counting them) :

      Fairly likely that African heritage just as real as perceived by you, prior.

      I thought we agreed that I looked surprisingly like you, albeit with a healthier glow and prettier baby blue eyes? :b More fairly unlikely than fairly likely on that evidence, I would say.

      I am in the process of becoming a Mauritian citizen so if not African by birthright, then soon to become African by self-determination. I quite like that actually : that in the end, I owed him nothing. It would be a shame to now accept that money.

      Yes, yes I'm being immature and having a tanty. But hey, financially I can afford to , so why not? I won't regret it. I'm also lucky that Ness doesn't care about the money either. All she wants are some trinkets ( the globe that was in his office , one of his paintings and a mustache cup) for the kids to remember him by. I'm happy to give in to that request.

      You have potential beyond yourself to do good things with any money inherited/accepted,

      The money will go in a trust fund for Maya.

      Her mother is well afaik but when you love someone and watch them die from the same disease that you once had , it must freak you out and make you wonder what the future holds for you.

      She is sending the little one for a holiday in May but she herself can't (won't?) come. Maybe she just needs a child-free break or maybe she's not happy with me , showing her disapproval by refusing my hospitality. She's so courteous and lady-like, it's hard to tell whether she's mad at me or not. sigh

      Ps: In other news, I almost bought another house on the weekend. Oops! I'm well overdue for a bender methinks. A proper one, not an ozb one. You in? :)

      • Half-African heritage likely anyway, and I do clearly recall you confiding quite a bit of Irish green in eyes of yours. Barring coloured contact lenses, I doubt that to have changed.
        Eyes a fair way from baby blue, at least since I was a baby. A notable dark shade of blue and have served me very well.

        I was going to link this for other reason, but maybe we can both defer in eye area to this chimera cat -
        (Can't even see the staples and from Narnia no less!)

        sectoral heterochromia

        I knew a girl with pie, eye. Modest maybe thirty-five degree slice, but good conversation starter for her I think, nevertheless.



        Do spare a thought for Maple, Jar Jar Binks.
        Very similar Dad-confusion to you (also Wiki's), but coming quickly to terms, with just a little help.


        The money will go in a trust fund for Maya.

        Indeed the other obvious option notwithstanding other resources to secure her future very successfully.

        In other news, I almost bought another house on the weekend. Oops!

        You could well wait until market in Melbourne softens further.
        Also don't forget the ever-encroaching gang-ridden Badlands, down there…

        You have an unpublished forum thread.
        Why would you even..?

        For your information, at least as to consequence -
        Strong rumour that broden signed a non-disclosure agreement with scotty, as only way to finally secure release from Penalty Box. Of others ultimately released, many relate stories hauntingly similar to this..

        In extremely roundabout way, that might just cheer you up, various grumbleguts.

        Should do, and good!

        Have a less angst-ridden weekend, if not starting today, then tomorrow!


        • +2

          I knew a girl with pie, eye

          So did I in my uni days. Quite a few actually. You couldn't get them to string 4 words together to make a sentence. They were more into non-verbal ice-breakers. But then where I come from "pie eye" means hammered.

          Talking about girls, my littlest love has had more women look into his eyes and go "Awwww, you're soooo cute! 😍" than I've ever had. And his eyesight is pretty amazing too : he can spot a Laughing Cow cheese triangle from over 20 feet away and bat his eyelashes and say "cheese peease" and has it in his hand before I can say "Eat your lunch!". We're not worried about his eyes:)

          I should close this thread. I'm not going to get a paternity test so there's no point to leaving open.

  • I should close this thread

    Before you do, let me know when you are properly back in happy frame of mind, so that I can post comment to OP, here.
    (A happy comment, but does reference death..)

    • +2

      I'm in a much better state of mind than I was last week. Post away! ☺️

      • +1

        An insta account to make you feel better about the Maya's Mum situation.
        Yes, even Japanese dogs are inscrutable…
        Account filled with videos like this, with some slight variation..

        Can maybe at some point send fun message with one link or other from account, when you are struggling to understand how she is feeling. Or just ask her to translate an in-video caption, or two, for you.

        You may have had a few takers for a cheezel/burger ring option in your poll, I reckon. Mod may fix if you ask nicely.


  • +1

    Good luck, whatever you choose to do. The trust fund idea you mentioned sounds like a good idea.

    I got behind on reading the Penalty Box thread. I was afraid the mods were going to unpublish it as they don't like these type of issues being questioned.

    • +2

      Thank you Pointscrazy. You're always so kind to me :)