
This Blood Type is So Unique, It’s Found in Only One Person
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New Blood Type Discovered in France — And Offers a Breakthrough in Transfusion Medicine
A French patient had a never-before-seen blood type, now officially recognized as the 48th blood group system. The discovery wasn’t just a stroke of luck; it was the result of years of meticulous research and full genetic sequencing. Of the 17 blood group systems discovered globally since 2012, 10 have been uncovered by France’s EFS and its research collaborators. For patients with rare blood types, discoveries like these offer hope. Every new blood group we identify adds another layer of precision and safety to modern transfusion practices. It could mean the difference between life and death when compatible blood is scarce. The information in this article is not offering medical advice and should be used for informational purposes only. Review the sources used below for this article: Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards.
After extensive genetic analysis of her blood samples, researchers from Inserm, Paris Cité University, the University of the Antilles, the French National Blood Service (EFS), and the National Reference Center for Blood Groups (CNRGS) published a surprising discovery: this patient had a never-before-seen blood type, now officially recognized as the 48th blood group system.
Blood Systems and Blood Types
Not all blood is the same — like the color of our eyes, our blood type is determined by our genes. Blood types vary based on specific antigens present (or absent) on the surface of red blood cells. These antigens are recognized by our immune system, meaning a transfusion with incompatible blood can trigger a severe or even life-threatening reaction.
The most familiar systems are ABO and Rh, typically shown as a letter followed by a + or – sign (e.g., A+, AB-, O+). These are the most clinically significant for transfusions because their antigens are very immunogenic, meaning that they are especially likely to provoke an immune response. While other blood group systems exist, their antigens are less reactive and are generally screened only if a patient shows rare or unexpected antibodies.
Read More: There’s a New Group of Blood Types. Here’s Why It’s Important
An Ultra-Rare Blood Type
But even well-established systems have their limits. In 2011, the CNRGS hit a puzzling roadblock when they failed to identify the antibody present in a patient’s blood. Without knowing her blood type, no compatible donor could be found. Years later, in 2019, researchers revisited the case and requested additional samples to try again.
This time, they went all in: sequencing the patient’s entire genome, roughly 22,000 genes. What they uncovered led to the identification of a completely new blood group system, dubbed PigZ. So far, it contains only one known blood type: GWADA negative, named in reference to the patient’s Guadeloupean origin.
This makes GWADA negative an ultra-rare blood type — perhaps even unique to this one person. Its discovery wasn’t just a stroke of luck; it was the result of years of meticulous research and full genetic sequencing.
Discovering New Blood Systems
The discovery marks a major milestone for transfusion medicine and underscores the persistence of researchers like Slim Azouzi, a specialist in rare blood groups. His team worked for over two years to understand this medical mystery, ultimately uncovering a completely new classification.
Finding a new blood group system is a rare and significant achievement, the very first one, ABO, was identified in 1900 by Karl Landsteiner. But in recent years, scientific advancements have sped up the pace. Of the 17 blood group systems discovered globally since 2012, 10 have been uncovered by France’s EFS and its research collaborators.
For patients with rare blood types, discoveries like these offer hope. Every new blood group we identify adds another layer of precision and safety to modern transfusion practices — and could mean the difference between life and death when compatible blood is scarce.
This article is not offering medical advice and should be used for informational purposes only.
Read More: Scientists Find Success in Creating Lab-Grown Blood
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Having worked as a biomedical research assistant in labs across three countries, Jenny excels at translating complex scientific concepts – ranging from medical breakthroughs and pharmacological discoveries to the latest in nutrition – into engaging, accessible content. Her interests extend to topics such as human evolution, psychology, and quirky animal stories. When she’s not immersed in a popular science book, you’ll find her catching waves or cruising around Vancouver Island on her longboard.
What Is ‘Gwada Negative’, the Rarest Blood Group Found in Only One Person on Earth?
Gwada Negative is an EMM-negative blood type, identified by the absence of the EMM antigen, a high-incidence antigen found on red blood cells in nearly all humans. Unlike other rare blood groups that may have a handful of known carriers, Gwada Negative has just one, making it the rarest blood type ever recorded. If the woman were to require a blood transfusion, no existing donor would be compatible with her blood, except herself. The discovery dates back to 2011, when a 54-year-old woman from Guadeloupe underwent routine blood tests before surgery.
As of June 2025, the International Society of Blood Transfusion (ISBT) recognises 47 unique blood group systems. With this latest finding by the French Blood Establishment (EFS), Gwada Negative becomes the 48th recognised blood group system, officially accepted by the ISBT.
What Is Gwada Negative?
Gwada Negative is an EMM-negative blood type, identified by the absence of the EMM antigen, a high-incidence antigen found on red blood cells in nearly all humans. The absence of such a universally present antigen is what makes this blood type extraordinarily rare.
The group is named “Gwada Negative,” after the local nickname for the islands of Guadeloupe, where the patient originally hails from.
How Was It Discovered?
The discovery dates back to 2011, when a 54-year-old woman from Guadeloupe, then living in Paris, underwent routine blood tests before surgery. An unidentified antibody was detected, but due to the technological limitations of the time, researchers could not determine its nature or classify the blood group.
Years later, in 2019, with advances in high-throughput DNA sequencing, researchers at the EFS revisited the case. Their work led to the detection of a mutation in the PIGZ gene, which affects how proteins attach to red blood cells. It was confirmed that the woman had inherited this mutation from both parents, making her the only known person to possess this exact blood group.
“She is the only person in the world who is compatible with herself,” said Thierry Peyrard, the medical biologist who led the study.
Why Is This So Significant?
What makes this discovery even more remarkable is the woman’s complete incompatibility with all known blood donors worldwide. Unlike other rare blood groups that may have a handful of known carriers, Gwada Negative has just one—making it the rarest blood type ever recorded.
This uniqueness, however, poses a serious medical challenge. If the woman were to require a blood transfusion, no existing donor would be compatible with her blood, except herself.
Unbelievable Blood Type Found in Just One Person – The Rarest of Them All!
Scientists discovered a rare blood type, “Gwada negative,” found in only one person globally. The finding adds a new layer of complexity to the already intricate world of human blood types, essential for safe transfusions. The Gwada negative blood type is the 48th officially recognized blood type. While the ABO-Rh system is commonly used, over 600 different antigens exist, suggesting millions of unique blood types. How many more undiscovered blood types could there be?
dailygalaxy.com
In a remarkable scientific breakthrough, researchers have identified a new blood type known as “Gwada negative.” This rare blood type, discovered on June 26, 2025, exists in only one person on Earth, a woman from Guadeloupe. The finding adds a new layer of complexity to the already intricate world of human blood types, essential for safe transfusions.
6 Key Takeaways New blood type called “Gwada negative” discovered.
Only one person on Earth has it.
Originated from a woman in Guadeloupe.
Genetic mutation causes this unique blood type.
Importance of identifying rare blood types highlighted.
Advances in gene sequencing may reveal more types.
The Gwada negative blood type is the 48th officially recognized blood type, highlighting the vast diversity in human blood. While the ABO-Rh system is commonly used, over 600 different antigens exist, suggesting millions of unique blood types. How many more undiscovered blood types could there be?
Fast Answer: The newly discovered “Gwada negative” blood type, unique to one individual, underscores the importance of ongoing research in blood transfusion safety globally.
This discovery raises important questions about blood compatibility and the implications for transfusion medicine. Understanding rare blood types is crucial for patient care, especially in emergencies. Consider these points:
Only one person in the world has Gwada negative blood.
Identifying rare blood types can prevent dangerous transfusion reactions.
Advances in genetic research may lead to more discoveries.
Medical professionals must adapt to these findings for better patient outcomes.
This discovery highlights the global relevance of blood type research, emphasizing the need for awareness and preparedness in medical settings.
As research continues to evolve, it’s vital for healthcare systems worldwide to stay informed about new blood types. This will enhance patient safety and care in transfusion practices.
This Blood Type is So Unique, It’s Found in Only One Person
Scientists have identified a new blood type that is so rare it exists in only one person on Earth. The blood type, called “Gwada negative,” was found by researchers at the French Blood Establishment (EFS) This rare blood type offers a new layer of complexity to the already intricate system of human blood types. Gwada negative is the 48th officially recognized blood type. With ongoing research and improved technology, scientists expect more new blood types to be discovered. It provides critical information for medical professionals to deliver better care for patients with rare blood types, reducing the risk of life-threatening immune responses. The genetic mutation responsible for Gwadanegative was inherited from both of her parents, who each carried the rare gene. The discovery began in 2011 when an unusual antibody was detected in the woman’s blood, and by 2019, DNA sequencing revealed the genetic mutation that caused this rare bloodtype.
A Unique Blood Type With A Rare Genetic Mutation
The Gwada negative blood type is the 48th officially recognized blood type, joining the ranks of well-known groups like A, B, AB, and O, each with positive and negative variations. This discovery, while extraordinary, underscores the vast diversity in human blood. Although blood type classification commonly follows the ABO-Rh system, scientists know there are many more possible blood types due to over 600 different antigens identified on human blood cells. This means millions of unique blood types could exist—though the International Society of Blood Transfusion (ISBT) currently recognizes only 47 distinct blood groups.
The Gwada negative blood type originated from a blood sample drawn from a French woman living on the Caribbean island of Guadeloupe. The patient, who was undergoing routine tests prior to surgery, unknowingly contributed to this major discovery. The key to this blood type’s uniqueness lies in a genetic mutation, which researchers uncovered after years of study. The discovery began in 2011 when an unusual antibody was detected in the woman’s blood, and by 2019, DNA sequencing revealed the genetic mutation that caused this rare blood type.
Gwada Negative: Only One Person On Earth Has It
This rare blood type is as unique as the individual who carries it. According to Thierry Peyrard, a medical biologist at the EFS, the French woman is “undoubtedly the only known case in the world” he added, “she is the only person in the world who is compatible with herself.”
This means that she is the only person compatible with herself for blood transfusions, a fact that highlights the extreme rarity of this blood type. The genetic mutation responsible for Gwada negative was inherited from both of her parents, who each carried the rare gene.
Understanding the antigen makeup of blood is essential for safe blood transfusions. Mismatched blood transfusions can lead to dangerous immune reactions, as the body may recognize foreign blood antigens as invaders. That’s why identifying such rare blood types is vital for ensuring patients receive the right blood for transfusions, especially in medical situations where only highly compatible blood can avoid serious complications.
#SciNews 𝗡𝗘𝗪 𝗕𝗟𝗢𝗢𝗗 𝗧𝗬𝗣𝗘 𝗗𝗜𝗦𝗖𝗢𝗩𝗘𝗥𝗘𝗗: ‘𝗚𝗪𝗔𝗗𝗔 𝗡𝗘𝗚𝗔𝗧𝗜𝗩𝗘’🩸
French scientists announced last weekend the discovery of the newest and rarest blood type found in a woman from the Caribbean island of Guadeloupe, dubbed ‘Gwada negative’.
The French… pic.twitter.com/ttKpNbArFd — ScienceKonek (@sciencekonek) June 24, 2025
The Importance Of Discovering New Blood Types
Though Gwada negative is the most recent addition to the list of recognized blood types, it is unlikely to be the last. Advances in gene sequencing are speeding up the discovery of new blood types. In fact, the 44th blood type, known as “Er,” was discovered just a few years ago in 2022. With ongoing research and improved technology, scientists expect more new blood types to be discovered at a rapid pace.
The discovery of Gwada negative is more than just a scientific milestone. It provides critical information for medical professionals to deliver better care for patients with rare blood types. As the ability to identify and match blood types improves, doctors can ensure better compatibility in transfusions, reducing the risk of life-threatening immune responses.
Emm-negative: A new blood type found in only one person
The International Society of Blood Transfusion has officially recognized the world’s 48th human blood group system: Emm-negative. Informally referred to as “Gwada negative,” after the Guadeloupean heritage of the only known individual with this blood type. The discovery dates back to 2011, when a 54-year-old woman underwent routine pre-operative screening. For the patient, this rare blood type means extreme caution. Any transfusion must be precisely matched to avoid immune complications. In the U.S., a unit of red blood cells typically costs around $225, excluding testing. For rare units, especially those deep-frozen for long-term storage, costs can soar to ten times that amount. In June 2025, ISBT delegates in Milan unanimously agreed to classify Emm as a new and independentBlood group system.
In June 2025, the International Society of Blood Transfusion (ISBT) officially recognized the world’s 48th human blood group system: Emm-negative. Informally referred to as “Gwada negative,” after the Guadeloupean heritage of the only known individual with this blood type, the classification is unique. As French biologist Thierry Peyrard noted, “She is the only person on the planet compatible with herself.”
The discovery dates back to 2011, when a 54-year-old woman underwent routine pre-operative screening. An unidentified antibody in her blood puzzled doctors. At the time, without the advanced genetic tools available today, the case was archived. Nearly a decade later, next-generation DNA sequencing uncovered a previously unknown mutation affecting the gene responsible for producing the EMM antigen, a molecule present on almost all human red blood cells.
The absence of this high-incidence antigen posed a significant challenge in transfusion medicine. Confirming the rarity and clinical implications of this finding required six additional years of peer-reviewed research. In June 2025, ISBT delegates in Milan unanimously agreed to classify Emm as a new and independent blood group system, now officially known as ISBT042.
Most people recognize their blood type by its ABO classification and Rh factor—positive or negative. However, red blood cells are adorned with dozens of other markers, or antigens, made from proteins, lipids, or sugars. The ISBT categorizes these into blood group systems, including the well-known Rh system and lesser-known groups like Vel.
The EMM antigen is considered a high-frequency antigen, meaning more than 99.99% of the global population has it. When this antigen is absent, as in the case of the Paris patient, the immune system may react aggressively to donor blood, potentially causing life-threatening hemolytic shock.
For the patient, this rare blood type means extreme caution. Any transfusion must be precisely matched to avoid immune complications. Her only option is autologous donation—banking her own blood ahead of planned medical procedures. This mirrors the situation for people with the Bombay blood group, another ultra-rare type first identified in 1952. While Bombay patients can sometimes find compatible donors globally, no such network yet exists for Emm-negative individuals.
The breakthrough came with next-generation sequencing, which allowed researchers to identify the exact gene deletion responsible for the missing EMM antigen. This technology, combined with expansive DNA databases, is rapidly accelerating the discovery of rare blood types—at least five new systems have been classified since 2012.
Rare blood types present serious logistical challenges. In the U.S., a unit of red blood cells typically costs around $225, excluding testing. For rare units, especially those deep-frozen for long-term storage, costs can soar to ten times that amount. Emergency situations involving rare blood types can incur thousands more in international shipping and delays that jeopardize lives.
The American Rare Donor Program already tracks about 100,000 individuals with uncommon antigen profiles. The addition of Emm-negative highlights the need for further expansion.
In response, French researchers have begun screening archived blood samples from Caribbean populations, hoping to identify additional Emm-negative donors. Even a small donor pool could provide essential reserves for future transfusion needs and emergencies.
In the long term, scientists are exploring lab-grown red blood cells made from stem cells engineered to match rare antigen profiles. Clinical trials are underway, with hopes of broader application within the next decade.
For now, the Paris woman who helped reveal the Emm-negative blood group continues her daily life — marked by a routine existence, yet with an extraordinary and singular designation on her medical record.