I think I’m O negative, but my parents are both positives (at least one is O positive). Because the family resemblances are so striking, it’s been a source of comic relief for years. My cousin the doctor said I might be a Bombay negative. I never got a chance to grill her on what that means.
I’m bored, so I just did a little Googling and read the Wikipedia entry. I confess, I really don’t understand what I’m reading.
If I’m O[sub]h[/sub], is my blood super-rare and highly unobtainable, and can O[sub]h[/sub] only receive blood of that type? E.g., should I give blood as much as possible and bank for myself if possible?
Don’t be afraid to give more explanation than merely answering the above questions. When I read about blood types, my eyes glaze over and I’ve no idea what I’m reading.
You might. Or your parents might each have one copy of the gene for Rh positive (which is dominant) and one copy of the gene for Rh negative, and you just happened to inherit two recessive genes. I’d say that’s probably more likely than your being a Bombay negative.
I don’t know my blood type, but I do know that it is positive and my mother’s blood type is negative. So I must have one copy of the Rh-positive gene and one copy of the Rh-negative gene.
From my limited knowledge of genetics, I don’t see how an O- woman could give birth to an AB+ child, unless there was a particular mutation. Type O and negative are both recessive genes. So she has to pass on a Type O gene and an Rh negative gene. That leaves the father to pass on either an A or a B or neither. He can also pass along either an Rh negative or an Rh positive. That leaves the child as anything else EXCEPT AB+. Either that or my understanding of the heritability of blood types is completely off base, which is also possible.
No, not normally. Remember how blood typing works. There are two different clotting proteins in blood, A and B, and each of these are created by a specific allele. So someone with AB blood type has to have both alleles for A and B, which means that they had to inherit an A allele from one parent and a B allele from the other. Someone with blood type O, like Flightless Bird’s mom, can’t have a child who has blood type AB, like Flightless Bird. So, it’s likely thet either Flightless Bird got his/her blood type wrong, his/her mom’s blood type wrong, or that Flightless Bird’s mom isn’t his/her biological mom.
Someone with AA or AO is an A, and someone with BB or BO (no jokes, please) is a B, right? Someone with O must be OO, right? Therefore, someone with OO could not have passed on either the A or the B to an AB child.
Blood types are based on the type of substances (glycoproteins) present on the red cells. I explained it all over in this thread if you’d like to have a quick look. The thing is, the A and B substances aren’t directly attached to the red cell themselves. Essentially, they’re two chemical modifications of a third substance, called the H substance, which is embedded in the red cell membrane of nearly everyone on the planet. If your cells only have the unmodified H substance on them, you’re Type O. (I know, makes more sense to call it Type H, but there you have it.) The whole H thing is usually never discussed, because it can get confusing and it’s not really going to affect anything with routine blood typing.
The Bombay O phenotype occurs when the H gene is missing, and is extremely rare. It’s a separate gene from the A/B gene, and so even if you’ve got the genetics to be a type AB, and you’re missing the H substance, you’re going to type as an O in the lab.
The problem with transfusing a Bombay O phenotype person is that the body makes antibodies against things it doesn’t recognize. So this person will have antibodies against A and B and H, and since everyone else’s blood has at least the H substance, even Oneg people, we can’t use it to transfuse him. These people, then, are encouraged to make autologous donations, which are then frozen and kept in case a transfusion is ever needed.
But… and I may be wrong, so hopefully someone with more blood experience can help me out here… as far as I know the Rh system is completely isolated from the ABO (and H) system and so just the fact that you’re type Oneg when your parents are Opos really shouldn’t be causing anyone to whip out the O bombay suggestion. Like **Anne Neville **said, your parents probably have one Rh pos gene each, and you got the recessives and ended up negative.
If you are in fact AB then neither of your parents could have been O. This means you have an error in your facts somewhere… either you are not AB or your mother is not O.
