The AB+ blood type results from specific genetic factors and is also influenced by population mixing.
Understanding Blood Types
Blood types are determined by the presence or absence of certain antigens on the surface of red blood cells. The ABO blood group system is primarily controlled by three alleles: A, B, and O. Individuals inherit two alleles, one from each parent. The '+' or '-' part of the blood type (like AB+) refers to the Rhesus (Rh) factor; positive indicates the presence of the Rh antigen.
Genetic Basis of AB Blood Type
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A and B Alleles: Individuals with AB blood type inherit both the A allele and the B allele. Neither allele is dominant, so both are expressed on the red blood cells. This results in red blood cells carrying both A and B antigens.
-
Rh Factor: The '+' indicates the presence of the Rh antigen. This is inherited separately from the ABO genes. Individuals with Rh positive blood have inherited at least one dominant Rh allele.
Population Mixing and AB Blood Type
According to provided reference, the AB blood group is a result of:
- Intermingling of Populations: The reference suggests that the AB blood group is a consequence of intermingling between Caucasian (commonly group A) and Mongolian (commonly group B) populations.
- Distribution: The AB blood group is found in low percentages among European populations but is more prevalent within the sub-continental Indian population due to the specific history of population mixing there.
AB+ Blood Type: Combining Genetics and Rh Factor
When an individual inherits both A and B alleles for the ABO system and also inherits at least one dominant allele for the Rh factor, they will have AB+ blood type.
| Blood Type | ABO Alleles | Rh Factor |
|---|---|---|
| AB+ | A and B | Present |
Key Takeaways
- AB+ blood type is the result of having both A and B antigens (from inheriting both the A and B alleles) and having the Rh antigen (from at least one dominant Rh allele) on red blood cells.
- Population mixing between groups traditionally having A and B blood types has also contributed to the current prevalence of the AB blood group globally.
