Scientists Discover New Blood Type Only Found In One Woman On Earth Today

Last updated on 6 AUG 2025

Blood is often viewed as one of the most fundamental and unifying elements of human biology—a life-sustaining fluid coursing through every person on Earth. Yet within this commonality lies extraordinary complexity. From the familiar A, B, AB, and O groups to the lesser-known subtypes that challenge even seasoned hematologists, blood types play a critical role in everything from emergency medicine to organ transplants. Now, a groundbreaking discovery is pushing the boundaries of what we thought we knew.

In an unprecedented finding, French scientists have identified a previously unknown blood type found in just one person—a woman originally from Guadeloupe. Known as “Gwada negative,” this blood type is so rare and genetically distinct that she is, for now, the only known individual on Earth who carries it. Her story, and the science behind it, opens a window into the deeply intricate world of blood classification—and the life-or-death implications that can accompany medical rarity.

The Complex World of Blood Types – More Than Just A, B, AB, and O

Blood types are often reduced to four simple categories—A, B, AB, and O—but the true picture is far more intricate. While these main groups are determined by the presence or absence of specific antigens on the surface of red blood cells, scientists have cataloged at least 48 distinct blood group systems to date, each with its own molecular fingerprint.

Antigens—molecules found on the surface of red blood cells—and the antibodies in plasma play critical roles in determining compatibility for blood transfusions. For instance, someone with type A blood carries A antigens and anti-B antibodies, while someone with type B has the opposite. AB blood types have both antigens and no antibodies, making them universal recipients, while type O blood—particularly O negative—has no antigens, which is why it’s often dubbed the “universal donor.” However, even this designation has its limits.

In rare cases, blood types can diverge from established classifications due to unique genetic mutations. These cases are not just academic curiosities—they can pose life-threatening challenges. If someone receives incompatible blood, their immune system may recognize it as a threat and mount an aggressive response, attacking the transfused cells. The result can be a serious, and sometimes fatal, transfusion reaction.

This complexity underscores the importance of ongoing research into blood diversity. With advances in genetic sequencing, scientists are uncovering novel blood groups that defy conventional categorization—reminding us that our understanding of the human body is still evolving. One of the most extraordinary recent findings in this realm is the identification of a blood type so rare that it has been found in only one person on Earth, a woman originally from Guadeloupe. Her case offers not only a scientific milestone but also a sobering reminder of the life-or-death implications of blood compatibility.

A Singular Discovery – The Case of ‘Gwada Negative’

In 2011, a woman from Guadeloupe had her blood drawn for routine testing prior to surgery in Paris. What seemed unremarkable at the time turned out to be groundbreaking. Doctors noted inconsistencies that didn’t align with any known blood groups, but the limitations of the era’s diagnostic tools meant they couldn’t reach a conclusion. It wasn’t until 2019, with advancements in DNA sequencing, that researchers at the French Blood Establishment (Etablissement Français du Sang, or EFS) were able to revisit the case and uncover something extraordinary.

Through genetic analysis, scientists identified a mutation in a gene called PIGZ—an alteration that impacted how proteins anchor to the surface of red blood cells. This mutation had not been documented before in the context of blood typing, marking the identification of an entirely new blood group.

The blood type was named “Gwada negative,” a nod to the woman’s Guadeloupean roots (“Gwada” being a colloquial abbreviation for Guadeloupe). According to biologist Thierry Peyrard, who played a key role in the research, the name was chosen in part because “it sounds good in all languages.” This naming also underscores the cultural and human dimension of scientific discovery—an intersection of identity and biology.

Gwada negative is now officially recognized as one of the 48 known blood group systems. Notably, the EFS has discovered 10 of the last 17 blood groups, reinforcing France’s position at the forefront of hematological research.

Living with a One-of-a-Kind Blood Type

While scientific recognition of Gwada negative is a milestone, the woman who possesses this unique blood type faces considerable risk. In emergency medicine, compatibility is everything. Blood transfusions depend on matching antigens to avoid immune rejection. For this woman, no known donor is a match—not even those with the universally accepted O negative blood.

“This woman is the only person in the world who is compatible with herself,” researchers noted. This presents a precarious medical scenario: if she were to need a transfusion, receiving any other blood type could trigger a catastrophic immune response.

To mitigate this risk, one of the few options available is autologous donation—the process of collecting and storing her own blood for future use. However, this approach has limitations. Blood has a shelf life, typically around 35 to 42 days for red blood cells under refrigeration. Longer-term preservation would require freezing the blood with specialized cryoprotectants in highly controlled environments—resources not always accessible in standard healthcare settings.

The case also shines a light on gaps in preparedness within healthcare systems for ultra-rare blood types. It raises ethical and logistical questions: Should rare blood be banked proactively? How can global registries be improved to track and store information on rare blood profiles?

The Genetics Behind the Anomaly – The Role of the PIGZ Gene

At the center of this medical mystery lies a mutation in the PIGZ gene, which is involved in the biosynthesis of GPI (glycosylphosphatidylinositol) anchors—structures that help attach specific proteins to the surface of cells, including red blood cells.

In individuals with conventional blood types, these anchors play a crucial role in how red blood cells interact with antibodies and the immune system. A mutation in this process, such as the one seen in the Gwada negative case, disrupts the expression or recognition of certain antigens. This leads to a blood profile that is not only unclassified by existing standards but entirely unmatchable by current transfusion protocols.

The implications of such a mutation extend beyond transfusion medicine. It raises broader questions in immunohematology about how rare genetic variations could influence immune response, susceptibility to certain diseases, or even outcomes in organ transplantation.

Importantly, the identification of this mutation wasn’t feasible in 2011. Only with the significant strides in next-generation sequencing and molecular diagnostics over the past decade could scientists decode the anomaly. This reinforces the value of re-examining biological samples as technology evolves—a practice that may yield further medical revelations in the future.

Why This Matters – The Call for Global Awareness and Blood Diversity

The discovery of Gwada negative blood is not just a scientific footnote—it’s a clarion call for deeper understanding of blood diversity and improved medical preparedness. Rare blood types are more common than one might think when viewed collectively. According to the World Health Organization, millions of people worldwide live with rare or poorly classified blood types, often going undetected until a medical crisis arises.

This discovery also underlines the need for inclusive research that represents ethnically and geographically diverse populations. Historically, blood group research has skewed toward populations in Europe and North America. Expanding research efforts globally increases the likelihood of identifying others who may share extremely rare blood profiles, potentially offering life-saving matches.

There’s also a human story at the heart of this scientific breakthrough. A woman unknowingly carried a singular blood signature that baffled scientists for nearly a decade. Her experience is a reminder of how medical science is deeply personal—and how much remains to be discovered within each of us.

As global health systems move toward more personalized medicine, the integration of advanced genetic tools, rare donor registries, and international collaboration will be key. Blood, as universal as it is unique, remains one of the most essential and enigmatic components of our biology. This discovery invites us to approach it not only with scientific rigor but with a renewed sense of humility and urgency.

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