No, geneticaly being AB+ would be impossible. Children generaly get there blood type from there father so we would expect the child to be O+. There are two exceptions to this rule, one is when the mother is RH (Rhesus factor) - (negative) then in rare instances the child can be born rh- even though the father is positive. And AB blood types come from having a A- mother and a B+ father.
There is also a rare blood group called ABO that can happen when an AB patient is given a blood transfusion with type O blood.


