My grandma is O- blood type, my grandpa is B+, but my mother is A+ and my aunt is AB+.
Is that possible?
I've just looked at different sources like this and all of them are saying that from O and B, comes only B or 0, and A and AB are forbidden.
How can my mother be a child of my grandparents and how my aunt can be a child of my grandma at all? Or can we 100% say that they are not the real children of those parents, assuming that all blood types are correct?