Blood Types

If one parent has A blood type and the other has O- is it possible for the baby to have AB?

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Wiki User
2013-09-30 12:55:19
2013-09-30 12:55:19

We are looking for the possible blood types of a baby.

Parental information:

  • Mother type A pos -- genetically AA or AO and Rh (++) or (+-)
  • Father type O neg -- can only be OO and Rh (--)
Baby receives one gene from each parent:
  • Baby is type AO (+-) = Type A pos
  • Baby is type AO (--) = Type A neg
  • Baby is type OO (+-) = Type O pos
  • Baby is type OO (--) = Type O neg
NOTE: There is no gene B here to make the AB blood.

Generally the baby will be either Type A pos/neg or Type O pos/neg.

HOWEVER: There is more to ABO blood typing that just the ABO gene.

There is also an inhibitory gene that will change any genotype into the phenotype O.

Therefore a person with genetically AB blood can be tested as having Type O.

  • What if baby is Type AB?
If type O parent has the inhibitory gene affecting his BB, BO or AB type,

then the Type AB baby is definitely possible.

Related Questions

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If one parent has blood type B and the other blood type O, it is possible to have a baby of blood type O or B. It is NOT possible (0% chance) to have a baby with blood type A.

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If with A + and O + Baby can have : A + or O + If with A + and O - Baby can have : A +, A-, O +, O - If with A - and O + Baby can have : A +, A-, O +, O - If A - and O - Baby can have : A + or O -

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Yes, that is possible. The first parents has a genotype of BO, while the second parent has a genotype of AO. The parents have a 25% chance of producing a child with AB blood, 25% chance of A blood, 25% chance of B blood, and 25% chance of O blood.

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