Are there any surprises in the genetic blood type rules?

Blood type is a classification of the quality and substance content of human blood. There are many types of blood types, but their basic functions are the same and they can play an important role in physical health. The specific blood type is related to genetic factors, which is also a commonly used reference standard in paternity testing. Are there any unexpected circumstances in the inheritance of blood types? Let’s take a look at the explanation below.

Your baby's blood type is determined by genes. A baby's blood type is determined by both the parents, and both will have an impact on it. Generally speaking, blood type is determined by the combination of three genetic factors, namely A, B, and O. Most of the time, the possible blood type of a baby can be determined based on the blood types of the parents. A child's blood type cannot be accurately determined by the parents' blood types, only the child's possible blood types. Therefore, a baby's blood type is determined by genes.

Humans have more than 15 genetically independent blood type systems, the most common of which is the ABO blood type system. There are four blood types in the ABO blood group system: A, B, AB and O. The genetic law is: ABO blood type contains three blood type genes, A, B, and O, which constitute six genotypes: AA, AO, BB, BO, AB and 00. Because A and B are dominant genes, whether it is homozygous (AA, BB) or heterozygous (AO, BO) containing A or B, the blood type will appear as A type or B type, and only the homozygous OO type will appear as O type.

The gene that controls ABO blood type is on the 9th pair of chromosomes. Since A and B are dominant genes and O is a recessive gene, as long as one of the 9th pair of chromosomes carries the A gene, the person will have type A blood regardless of whether the corresponding site on the other chromosome contains the A or O gene. For type O blood, both chromosomes in the 9th pair must contain the O gene. If one of the 9th pair of chromosomes carries the A gene and the other carries the B gene, it will be AB blood type. Generally speaking, blood type does not change throughout life. Most people can determine their possible blood type based on their parents' blood types, but to find out what their specific blood type is, they still need to go to the hospital or participate in blood donation for testing!