Gwada Negative Blood Group

Gwada Negative Blood Group

Why in News? 

Scientists in France recently identified the rarest known blood group in a 68-year-old woman from Guadeloupe during a standard medical examination. This unique blood type named “Gwada Negative” has surprised the medical world. 

What is Gwada Negative Blood Group?

• About: The Gwada Negative blood group refers to a newly identified human blood type that lacks the EMM antigen, a molecule generally present in the red blood cells of almost all people. This unique pattern led scientists to categorize it as a completely distinct blood group outside the existing 47 known groups.

• Recognition: In June 2025, after thorough genetic and antigenic analysis, the International Society of Blood Transfusion (ISBT) recognized this blood group as the 48th blood group system. The formal announcement came after more than a decade of scientific inquiry. 

• Features: This blood group exhibits several features that set it apart from any other group identified so far:

• • • EMM Antigen Absence: The red blood cells in Gwada Negative blood do not carry the EMM antigen, which is present in nearly all humans. This makes it immunologically incompatible with all other blood types.
    • Exclusive Compatibility: This newly discovered blood group is so unique that the person can only receive their own blood, as other types may trigger dangerous immune reactions.
    • Inheritance Pattern: In this blood group a person inherited mutated copies of the PIGZ gene from both parents, making it a recessively inherited trait. 

• Scientific Nomenclature: The term “Gwada Negative” was inspired by the island of Guadeloupe, where the woman was born.

• “Gwada” is a local nickname for the island, and scientists found it fitting to name the blood group after her place of origin.

• The addition of “Negative” refers to the absence of the EMM antigen. 

• In official terms, the ISBT refers to this as part of the EMM-negative phenotype.

• Significance: The discovery of Gwada Negative blood group holds several implications:

• • Blood Transfusion Safety: It highlights the need for extremely precise blood matching. Any mistake in transfusion involving such a rare type could lead to fatal reactions.
  • Genetic Insight: The mutation in the PIGZ gene provides researchers a deeper understanding of genetic influence on blood types and immune function. This case draws attention to the importance of rare blood donor registries. 
  • Future Research Directions: Scientists are exploring gene-editing and lab-grown red blood cells using stem cell technology that might one day help patients with extremely rare blood types like Gwada Negative.

How Was Gwada Negative Discovered?

• Initial Blood Testing: In 2011, a 54-year-old woman from Guadeloupe, living in Paris at the time, visited a local hospital. She was scheduled for a surgical procedure and required a routine blood test. Her blood sample triggered unexpected reactions, repeated tests confirmed that her blood had an unknown antibody pattern.

• Scientific Reinvestigation: In 2019, with the arrival of Next Generation Sequencing (NGS) in hematology, researchers at a French medical research institute decided to revisit her case. The new genetic analysis revealed that she had a mutation in the PIGZ gene. This gene controls the production of an enzyme that attaches specific sugar molecules to red blood cells.

• Official Recognition: After nearly 14 years since her initial test, the case finally gained formal recognition by ISBT in June 2025 as the 48th recognized blood group system.

Some Important Types of Blood Groups

• ABO Blood Group System: The ABO system sorts human blood into four categories—A, B, AB, and O—based on specific antigens on red blood cells and corresponding antibodies in the plasma.

• • • Type A: Red cells have A antigens. Plasma contains anti-B antibodies.
    • Type B: Red cells have B antigens. Plasma contains anti-A antibodies.
    • Type AB: AB blood has both A and B antigens on the red cells and lacks anti-A and anti-B antibodies in the plasma. This type can accept blood from any ABO group, making it the universal recipient.
    • Type O: Red blood cells in this group do not carry A or B markers. The plasma has both anti-A and anti-B antibodies. This type can safely give blood to all ABO types and is called the universal donor.
    • According to World Health Organization data, O is the most common blood type worldwide, found in about 44% of people, while AB is the rarest, occurring in fewer than 5% globally.

• Rh Factor (Rhesus System): The Rh system focuses on the D antigen, also called the Rh factor. When the Rh protein is present on red cells, the individual is considered Rh positive. If the Rh protein is missing, the person is Rh negative.

• If someone has A markers along with the Rh protein, their blood type is A positive.

• If B markers are present but the Rh protein is missing, the blood type is B negative.

• • • Globally, around 85% of people are Rh-positive, while 15% are Rh-negative, though this ratio varies by region and ethnicity.
    • If an Rh-negative mother carries an Rh-positive baby, it can cause hemolytic disease of the newborn (HDN) unless properly managed.

• Other Blood Group Systems: Beyond ABO and Rh, medical science recognizes over 45 other blood group systems, each based on different genetic markers. Some notable ones include:

• • Kell System: Important in transfusion reactions and pregnancy-related issues.
  • Duffy System: Influences susceptibility to malaria. People with Duffy-negative blood are more resistant to certain malaria strains.
  • Lewis System: Often used in forensic studies and paternity cases.
  • MNS System: Plays a role in autoimmune responses and kidney transplant compatibility.