Why is AB the rarest blood group in the world?

A person with type AB blood can be considered quite rare. So why are so few people carrying this blood group?

1. Why split into blood groups?

All blood contains the same basic components: red blood cells, white blood cells, platelets and plasma.

Antigen on the surface of red blood cells determines blood type

Red blood cells are produced in the bone marrow, which carries oxygen in the body. In every 2-3 drops of blood contains about one billion blood cells. The number of red blood cells exceeds that of platelets (functions to clot blood at the wound, helps stop bleeding) and leukocytes (helps protect the body from bacteria and pathogens). Every 600 new red blood cells have 40 platelets and a single white blood cell.

Antigens determine which blood type a person belongs to.(Photo: Wisegeekhealth.)

Dr. Leslie Silberstein, spokesperson for the American Society of Hematology, explains that on the surface of red blood cells there are proteins that bind to carbohydrates - a fundamental marker for which blood groups belong. They are called antigens, which are usually classified into eight basic blood groups: A, B, AB and O, each divided into Rh + and Rh-.

Blood type A has only one antigen A on the surface of red blood cells. Similarly, blood group B has only antigen B, blood type AB has both antigens and blood type O without both of the 4 basic blood types that are most important, because they determine the patient's blood type. Can receive safe blood transfusion.

Patients who receive incompatible blood often have very dangerous reactions. Their immune system will recognize strange antigens on the surface of blood cells, leading to conflicts.

If you have Rh + blood group, it means that the blood contains Rhesus D antigen, and Rh- means not. This is also a genetic trait affecting blood transfusion.

Basic blood transfusion rules.(Photo: Redcrossblood.)

A survey by Stanford Medical School (USA) calculated the blood group rate of the general population as follows:

1. O +: 37.4%
2. O-: 6.6%
3. A +: 35.7%
4. A-: 6.3%
5. B +: 8.5%
6. B-: 1.5%
7. AB +: 3.4%
8. AB-: 0.6%

This is just a general ratio, because they are slightly different based on ethnic background. For example, the number of Asians with B blood is higher than that of whites, while the O blood group is more common in Hispanic communities.

The world's rarest blood group

We inherit a blood group gene from each parent. However, if one of the two genes you inherited is O, this will not have much effect on the other gene. Therefore, a blood type A person may be able to inherit the A gene from both parents, or receive the A gene from one person and the O gene from the other. The same is true for people with type B. Blood type O people inherit two 2 O genes from their parents.

People with AB blood group inherit the A gene from their parent or mother and the B gene from the other. Based on the number of people with blood types A and B, the incidence of this special combination will be lower than in other cases. The rate according to the survey also proved visibly why AB blood is so rare.

You should donate blood regularly regardless of the group.(Photo: Getty Images.)

People with rare blood types AB, but AB +, have a great advantage of getting any blood type. If you carry O-type blood, all of which need you because O- can pass on to anyone who needs blood.

Every year the number of people needing blood transfusions is very large. So no matter what kind of blood you have, you should occasionally donate blood as a gift for others.

According to Zing