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A landmark discovery has added a new chapter to medical science with the identification of a never-before-seen blood group, officially named “Gwada negative.”
This marks the 48th blood group system recognized globally, according to France’s national blood agency, the French Blood Establishment (EFS).
The blood group was identified in a French woman originally from Guadeloupe, a Caribbean island. What makes this even more remarkable is that she remains the only person in the world known to have it.
According to Thierry Peyrard, a medical biologist with EFS, this rare genetic phenomenon makes her “the only person in the world who is compatible with herself.”
The woman, who was 54 at the time of testing and living in Paris, had undergone routine pre-surgery blood work in 2011, when scientists discovered a “very unusual” antibody. Despite its uniqueness, the scientific tools at the time were insufficient to unlock its origin.
It wasn’t until 2019, using advanced high-throughput DNA sequencing, that researchers were able to pinpoint a genetic mutation responsible for this extraordinary blood type. The breakthrough was finally recognized in June 2025 by the International Society of Blood Transfusion (ISBT) at a scientific meeting in Milan.
The name “Gwada negative” pays homage to the woman’s Guadeloupean roots and, as Peyrard noted, “sounds good in all languages.”
Interestingly, the woman inherited this rare blood group from both parents, each carrying the same mutated gene, making the condition an ultra-rare recessive trait.
Now, researchers are actively searching for more individuals with this blood group. The goal? To offer better care options for patients with rare blood types and potentially discover other unknown systems.
As the EFS emphasized, “Discovering new blood groups means offering patients with rare blood types a better level of care.”
