Is a child’s blood type inherited from the father or the mother?
Jul 13, 2021
Source: Cainiu Health
Dr. Xu Min
Introduction
A child’s blood type is determined jointly by both parents. For example, if the father has type A blood and the mother has type B blood, the child may have type A, type B, type AB, or type O blood. In such cases, type A could be said to be inherited from the father, and type B from the mother. However, if the father has type O blood and the mother has type AB blood, the child can only have type A or type B blood—neither matching the father’s nor the mother’s blood type.
Taking the common ABO blood group system as an example, blood type is determined by combinations of three inherited alleles—A, B, and O. In most cases, a baby’s possible blood type can be predicted based on the blood types of the parents. So, does a child’s blood type follow that of the father or the mother? Below, we address this question.
Does a child’s blood type follow the father’s or the mother’s?
A child’s blood type is determined jointly by both parents. For instance, if the father has type A blood and the mother has type B blood, the child may have type A, B, AB, or O blood—each with a 25% probability. In such cases, type A could be said to “follow” the father, while type B could be said to “follow” the mother. However, if the father has type O blood and the mother has type AB blood, the child can only have type A or type B blood—neither matching the father’s nor the mother’s blood type. Therefore, it is inaccurate to simply state that a child’s blood type “follows” one parent or the other; rather, it results from the combined genetic contributions of both parents—and rare mutations may even occur. Thus, a child has a 50% chance of inheriting blood-type-related genes from the father and a 50% chance from the mother. Blood type is genetically inherited; specifically, a baby’s blood type is determined by inherited genetic material.
Knowledge Extension: How is blood type inherited?
1. Blood type inheritance occurs via chromosomes within cells. Human somatic cells contain 23 pairs of chromosomes, each pair consisting of two chromatids—one inherited from the father and the other from the mother. Chromosomes are primarily composed of deoxyribonucleic acid (DNA), which determines inherited traits and biological functions.
2. The ABO blood group system is controlled by three alleles—A, B, and O. However, each person carries only two ABO-system alleles on chromosome 9—one inherited from each parent. These two alleles constitute a pair of codominant or dominant–recessive alleles, such as AO, AA, BO, BB, AB, or OO. Alleles A and B are codominant and dominant over allele O, which is recessive. When a dominant allele is present, expression of the recessive allele is suppressed.
The above provides an overview of whether a child’s blood type follows that of the father or the mother. We hope this information is helpful to you.
