Blood Type: Screening Test for Paternity

Patient: Hi my question is can a mother who has blood type O and a father who has blood type A have a child with blood type AB as i read recently that this is not possible and am very confused. please help me as i need to start researching about myself if this is true. My father died a couple of months ago and i have no contact with my mother. i thank you annette lanzon

Doctor: The possible blood types of children with one parent having blood type O and another having blood type A are blood type A and blood type O. Bearing a child with an AB blood type is very unlikely. As much as I don’t want to be the bad news bearer, there is a possibility that he was not your father. However, blood types are only preliminary investigations for paternity. There are DNA tests which will confirm paternity, a mere hair strand can be sampled for those tests but it can be pricey. I do wish you all the best. Take care always.