Tuesday, September 26

How many Rare Blood Types are there?


What is blood type?

When we talk about the fluid that runs in our veins, we also talk about the type. We all know that there are different blood groups. Within a family, siblings from same parent might have different blood groups. Now if you are wondering what blood types is, lets start from the basic. The blood is composed of Red blood cells. white blood cells and the antigens. The red blood cells carry oxygen around the body. The white blood cells help in fighting against the infections and the platelets help in clotting the blood in case of an injury.

Antigens and the blood type

Now, the antigens in your blood is what gives you the blood type. These antigens sit on the red blood cells. Antigens are composed of proteins and sugars. They distinguish your blood group. The world recognizes 33 blood typing systems, among which 2 are most famous. These are basically taught in school and accepted by the different health organizations. They are the ABO and the Rh-positive/Rh-negative blood group systems. Before dwelling into rare blood types, lets also build our knowledge for these two systems:

ABO system

This system relies on the two antigens A and B. One can have A, B or both. If one doesn’t have AB antigens, then the blood type is O.

Rh factor

The most widely used and recognized blood type system is the Rh factor. Which relies on teh antigen named Rh Factor. If the red blood cells have Rh factor, their blood type is positive, if they don’t their blood type is negative. Thus giving us 8 blood types in total with a positive and negative tag. These are:

  • A-positive
  • A-negative
  • B-positive
  • B-negative
  • AB-positive
  • AB-negative
  • O-positive
  • O-negative

Which is the rarest Blood Type?

The rarest blood type will be according to the region. Because your blood group depends upon the blood type of your parents. Blood group is genetic! This means that the country or region you live in will decide the rarest blood type of there. however, since many countries don’t disclose their blood type data, especially the developing ones, we are focusing on US.

Thus in US, AB-negative is the rarest blood type. Yet, only 0.6% of the population has it. While in US, the most common blood type is O-positive with 37.4% population having it!  The following table has been taken from Stanford School of Medicine Blood Center: 

Blood type Average percent
of U.S. population
AB-negative .6%
B-negative 1.5%
AB-positive 3.4%
A-negative 6.3%
O-negative 6.6%
B-positive 8.5%
A-positive 35.7%
O-positive 37.4%

Different countries have different rarest and common blood types. While in US, only 8.5% of population has b-positive blood group, while in India it is the most common blood group! In Pakistan Rh-negative is the most rare blood type.

What is Golden Blood?

The rarest of rare blood types across the globe is the Golden Blood, which is also known as the Rhnull. the frequency of its occurrence is 1 in 6 million people. This blood type has no Rh-antigens, thus known as Rhnull.  is a rare blood type that doesn’t contain any Rh-antigens in red blood cells. More resaerch are underway for this Phenotype. If any person has it, he shall immediately contact his doctor so that would be listed in worldwide Rhnull or Golden blood type holder.

ALSO READ: What is RH-NULL Blood? Does this blood type exist?

With its rareness, this blood type is also vulnerable to developing chronic hemolytic anemia. In which the body starts destroying the immature  red blood cells.

What determines the Blood type?

Your parents determine your blood type. You, like many other things inherit the blood type. Thus, you can inherit a A gene from father and B from mother resulting in a AB blood group! But that might not be the case in your siblings. each one has a probability to inherit different gene.

You might inherit an A gene from one parent and a B gene from the other, resulting in the AB blood type. But since O doesn’t contain any antigens, it cannot affect A and B.

Here is a chart for you to understand

Parent A AB AB AB AB B A A O O O
Parent B AB B A O B B A B A O
Probability of blood type A, B, or AB A, B, or AB A, B, or AB A or B O or B O, A, B, or AB O or A O or B O or A O

The risks of not knowing your blood type

What if you have the rarest blood type? What if you are losing a lot of blood in a injury and need immediate blood? if wrong blood is transfused in the body, which means a blood not matching your blood group. Then your immune system, will start reacting against it causing life threating conditions.

Universal recipients of Blood

People with blood group AB positive are universal recipients. They can receive blood from any blood group. they have both the A,  B and Rh antigens, making them receive any blood type.

Universal donors of the blood

Everyone can receive type O blood because it doesn’t contain any antigens. This is why people with type O blood are considered “universal donors.” But people with type O blood can receive only type O blood.

the Rh-factor makes O-negative the universal donors.

Ultimate rare blood type

Through our publications, we at Planet Today urge people to be blood donors. Know your blood type and donate blood. it is safe for healthy people to donate blood as it can save lives of many. For hospital patients, the rarest blood type is the one not on the shelf when they need it to save their lives. They can be patients with serious injuries, cancer patients or chronic disorder patients.

Only 1% donors for AB-Negative are available. However, as they are few people having the blood group AB-negative, the demand for this blood type is low.  The most rare type of blood type is  Ro subtype.

What is the Ro subtype?

Founded by Dr Alexander Weiner in 1943, Ro subtype is a variation of the Rh positive blood type. this means that a person may be carrying  O positive, A positive, B positive or AB positive blood. everyone has a subtype and thereby it is not dangerous to have it.  Over the years, the demand for Ro subtype is increasing by 10-15% while their donors are only 2%!

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