How could I have this blood group?

[ginger899]

I am blood group AB negative. In the old days I would have been one of the 'blue baby' ladies.

I have always known my mother is O positive, as she donated blood when she was younger and had a donor card.
For years I never knew what my father's blood group was, then just before he died, I saw this written on his hospital chart. I only glanced very briefly, and cannot remember quite what it was, but DO know it was not AB negative (I think it was O but I can't remember whether neg. or pos.

When I told my mother about this she said no-one she knew in the family was AB negative.....and way back of course no-one knew their blood group. I asked her if there were any women in the family way back, who had borne only one child.....no-one seemed to check out.

This is a total mystery to me. How did I get AB neg. blood group??

[ginger899]

Thank you so much, but I am still confused. I would have to have parents with AB,A, or B to result in me being AB?? So as I definitely know my mother is O+ (not AO) My father, as I said, I am not certain, but seem to remember it was O too (but could have been O neg.)
I am sure she IS my mother, and I am sure my father WAS my father. (?)We have so many physical characteristics in common!
Once I asked a doctor about this, and her reply was that I could be a 'throwback' from a grandparent/great-grandparent....but that doesn't check out either. In the old days a woman with AB negative would only have been able to have one child. The subsequent one(s) would probably not have made it and would have been 'blue babies'. My grandmother (mother's side)had 3 children (that survived) My great-grandmother had 15. (Father's side) mother had 2, grandmother had 4.

[Jordanna Joaquina, MS, CGC]

There are four major blood types: AB, A (which can be either AO or AA), B (which can be either BB or BO) and O (which is always OO). Certain combinations of the first three blood types: AB, A, or B can result in an AB child.

The Rh factor is inherited separately and a person is either ++ (positive), + - (positive) or - - (negative). Combinations of + - and/or - - can result in a - - (negative) child.

Hope this information is helpful.