Determining bloodline according to blood type

Although the ABO blood count method can predict the likelihood of parental blood relation but accuracy is very low, therefore, it is not acceptable for legal purposes.

ABO blood group system?

In the early 1900s, based on the presence of antigens on red blood cells, scientists determined that humans had four different blood groups: O, A, B and AB.This blood type classification system (called ABO blood group system) provides doctors with important information to choose the right blood group for blood transfusions.

Blood groups can be hereditary for the next generation.

Since 1920, scientists have found that blood groups can be inherited for the next generation. Scientists claim that they can predict the relative blood type of their children based on their parents' blood type. In contrast, the blood group of the child and the known parent (or mother) is also used to determine the relative blood type of the unknown parent (or father). Thus, scientists at that time used blood groups to verify a child's father or mother. However, the determination of bloodline based on the genetics of the blood group is relative, so the accuracy is not high.

Scientific basis

Different genotypes produce different blood groups. This is explained in the following table:

Different genotypes produce different blood groups.

Determination of bloodline based on ABO blood group system

We provide the following two cases to illustrate how blood determination is based on the ABO blood group system (assuming no mutation):

Case 1 : Know the blood type of Father and Mother, thereby deduce the blood type of the child (Table 1)

Table 1 . Blood group of children when they know the blood type of their father and mother

From the blood group of parents can deduce their blood type.

For example:

Both father and mother have blood type O that can only give birth to a child with blood type O. If the "Son" does not have a blood type O, it is not the parent of the parents.

If Daddy's blood group A and Mother's blood group B, then the blood group of the child can be: A, B, AB or O. In this case, the blood group is completely meaningless in determining bloodline.

Case 2 : Knowing the blood type of Mother and Child, thereby deducing the blood type of the Father (Table 2)

Table 2 . Blood of the Father when he knows the blood of Mother and Son

Looking at table 2, we can see that only the blood group of the Father must be determined.

For example:

If Mother is B, Son is A, Father is A or AB.

If Mother is AB, Son is A, biological father is able to carry any blood type in 4 blood groups. This shows that if only based on blood type, no man will be excluded as the father of the child.

In particular, if Mother is AB, I cannot be O, if Mother is O, I cannot be AB.

Thus, the determination of bloodline based on blood type is only relative, not affirmative. Therefore, blood type testing is not a useful tool in analyzing the parent-child relationship.