What is Bombay blood group? HH Blood group and ABO Group system.

What is Bombay Blood Group?

A small fraction of people have the Bombay Blood Group, also known as the h/h blood group, which is an uncommon blood type. The H antigen, which is a precursor to the A, B, and AB blood group antigens, is absent in people with this blood group. Because of this, it is challenging to classify them using the conventional ABO blood type system. Transfusions involving people with the Bombay Blood group must use blood that is compatible with them.

Who discovered Bombay Blood Group?

 Dr. Y.M. Bhende was the first to demonstrate the existence of a genetic variation in humans called H/h. Since this unusual blood group was initially discovered in Bombay (Mumbai), India, in 1952, it is also known as the Bombay blood group. Most people with the Bombay phenotype reside in Southeast Asia. The "Bombay Blood group" affects about 179 people in India or 1 in 10,000 people. The parents of the Bombay phenotype exhibit a significant degree of consanguinity. The vintage people with Indian ancestry have been shown to have the Bombay phenotype. With a prevalence of 1 in 250,000, it is relatively uncommon in Caucasians. There is a great risk of misinterpretation or under-exploration of the Bombay blood group in our nation because voluntary blood donor organizations and different blood banks regularly perform "only forward or cell type grouping" using the finger prick method. This Bombay group, if misdiagnosed, can result in a deadly hemolytic transfusion response. This is why our recommendation is to make "routine serum typing or reverse grouping confirmation" as well as "O" cell control in reverse grouping procedure in every Transfusion Medicine Department, Blood Bank, or Blood Donor Center, and this practice should be required to reduce the risk of fatal complications. Transfusion hemolysis response. We shall highlight this blood group's prevalence, molecular biology, and clinical significance in this view.

 The absence of the H antigen is the primary distinction between the Bombay blood type and the typical blood group. Due to a genetic abnormality, people with the Bombay blood group do not have the H antigen on the surface of their red blood cells. It is difficult to establish the blood type of these individuals using conventional ABO blood typing techniques because the absence of the H antigen changes how the A, B, and AB antigens are expressed. Contrarily, those with normal blood groups express ABO antigens and have the H antigen, which can be precisely identified through traditional blood typing, in people with normal blood groups.

Based on the presence or lack of antigens on the surface of red blood cells, the ABO blood typing system divides people into four major groups: A, B, AB, and O. The genetic mix acquired from one's parents determines these antigens. The H antigen is essential because it acts as a precursor to the ABO antigens. The ABO antigens cannot be effectively expressed if the H antigen is missing.

Due to a genetic mutation that hinders the development of the H antigen, individuals with the Bombay Blood group do not produce it. Therefore, even though they have the genes for A, B, or AB antigens, their blood cells cannot correctly express them. This creates a rare circumstance where the conventional ABO blood typing procedure cannot reliably detect the blood type.

Bombay Blood Group found in which people?

People with the Bombay Blood group are occasionally referred to as "Universal Donors" since their blood does not contain ABO antigens that could cause recipients to develop an immunological reaction. They can only receive blood from donors who have the same uncommon Bombay Blood group, thus this is a little misleading. It can be difficult to get appropriate blood for them, and careful cross-matching is needed to guarantee safe transfusions.

The Bombay Blood group is extremely uncommon, hence it is mostly found in particular communities, like people of Indian or South Asian descent. This blood type is strongly influenced by genetic inheritance, and a kid must be born with the precise gene mutations carried by both parents to have the Bombay blood group.

Differences between the Bombay blood group and normal blood groups:

1. Antigen Expression: Because certain genes are present in normal blood types, the ABO antigens (A, B, and AB) are expressed on the surface of red blood cells. contrasted with persons due to a genetic abnormality, people with the Bombay Blood group do not have the H antigen. The A, B, or AB antigens cannot, therefore, be seen on their red blood cells.

2.  Blood typing:  The ABO and RhD systems are used to determine whether or not A, B, and Rh antigens are present in normal blood. Standard ABO typing may not reliably identify the blood type of people who belong to the Bombay Blood group because the absence of the H antigen hides the expression of ABO antigens.

3.  Blood transfusions:  Serious immunological reactions may result from blood transfusions between people of different blood types. Because they lack ABO antigens, people with the Bombay Blood group are occasionally thought of as universal donors, but they can only receive blood from people who also have the rare Bombay Blood group. This makes it extremely difficult to find suitable blood.

4.  Populations Impacted The Bombay Blood group is quite uncommon and frequently seen in specific populations, especially those of South Asian or Indian origin. In contrast, the distribution of normal blood types throughout the world's population is determined by the frequency of various blood group alleles.

5.  Genetic Foundation: The H antigen, which is necessary for the expression of the ABO antigen, cannot develop, leading to the establishment of the Bombay Blood group. Different combinations of the ABO and RhD gene alleles that are inherited from parents determine normal blood types.

6. Medical Considerations: To precisely identify their blood type and ensure safe transfusions, people with the Bombay Blood group require specialist testing. In contrast, those with normal blood types may be reliably typed using conventional procedures.

7. Medical Identification: People with the Bombay Blood group may need to carry cards that list their blood type or wear medical identification bracelets to let medical personnel know about their specific compatibility needs.

In conclusion, the main obstacle to blood compatibility and typing for people with the Bombay Blood group is the absence of the H antigen in these individuals. The rarity of this blood type highlights the value of precise blood matching and specialist care for those who have it.

Bombay Blood Group’s Distinct Characteristics and Challenges:

1.  Non-Traditional Blood Typing: The blood type pattern of people with the Bombay blood group is distinctive. Due to the absence of the H antigen, which is necessary for the expression of ABO antigens, standard ABO blood typing may not reliably diagnose their blood type.

2.  Antigen Absence: The expression of the A, B, and AB antigens on the surface of red blood cells is impacted by the absence of the H antigen. Blood from people with the Bombay Blood group is incompatible with the majority of other blood types due to its distinct antigenic profile.

3. Universal Donors: People with the Bombay Blood group are frequently dubbed "universal donors" in terms of ABO compatibility because their blood lacks the ABO antigens, however, this term can be deceptive because they can only donate to people with the same uncommon blood type.

4. Careful cross-matching is necessary to discover appropriate donors for transfusions involving people with the Bombay Blood group. Beyond the conventional ABO and RhD systems, this procedure entails assessing the blood compatibility of the donor and receiver.

5.  Reactions to Transfusions: Incompatible transfusions can trigger severe immunological reactions, which might result in complications that could be fatal. It becomes crucial to find a matched blood donor to avoid negative reactions.

6.  Population Prevalence Extremely uncommon, the Bombay Blood group is usually found in particular populations, such as individuals with South Asian or Indian ancestry. It is difficult to locate appropriate donors within these communities due to their scarcity.

7. Genetic Passing on: The H antigen is specifically mutated in the Bombay Blood group, which has a genetic basis for this. For a child to inherit the Bombay Blood group, both parents must have these mutations.

8.  Medical identification, such as bracelets or cards, may be required for people with the Bombay Blood group to let healthcare professionals know about their specific blood type and compatibility needs.

9. Limited Blood Supplies: Due to the rarity of the Bombay Blood group, it might be challenging to maintain a sufficient supply of compatible blood for transfusions, especially in urgent situations.

10. Research and Awareness: To better comprehend the genetic foundation of the Bombay Blood group and to enhance methods for finding compatible donors, ongoing research and awareness activities are required.

Finally, the absence of the H antigen is the cause of the Bombay Blood group's distinctive traits, which result in unusual blood type, compatibility issues, and specialized transfusion needs. The significance of this blood type is highlighted by its rarity, highly precise blood-matching technology, and specific treatment for those with the Bombay Blood group.

People with Indian or South Asian ancestry are more likely to have the Bombay blood group. Even within these populations, it is a very rare blood type. People with Indian ancestry are more likely to have the Bombay blood group because the genetic mutation that causes it is more common in some ethnic groups. It's crucial to remember that the Bombay blood group is still rather rare even among these populations.