Why Would a Child Be O-Type If the Father Is B-Type and the Mother AB-Type?

Question

The father’s blood type is B-type, and the mother’s blood type is AB-type, but the child’s blood type is O-type. Why would the child’s blood type be O in this situation? Are there appropriate treatment methods? Please provide medical advice.

Answer

Hello! I’m glad to help you with this. According to Mendelian inheritance laws, if the father is B-type and the mother AB-type, the child’s blood type theoretically could be A-type, B-type, or AB-type, but not usually O-type. I suggest that both parents retest their blood types, as there may have been an error in judgment. Please go to the hospital again for a check-up to confirm whether there was an error in judgment.