French Woman from Guadeloupe Identified as Carrier of New Blood Type
A French woman from the Caribbean island of Guadeloupe has been identified as the only known carrier of a new blood type, dubbed “Gwada negative,” France’s blood supply agency has announced. This groundbreaking discovery comes 15 years after researchers received a blood sample from a patient undergoing routine tests ahead of surgery, as reported by the French Blood Establishment (EFS).
The EFS recently made the announcement on social network LinkedIn, stating, “The EFS has just discovered the 48th blood group system in the world!” This significant finding was officially recognized by the International Society of Blood Transfusion (ISBT) in Milan, marking a new milestone in the field of transfusion medicine.

Thierry Peyrard, a medical biologist at the EFS, revealed that a rare antibody was first detected in the patient in 2011 but further research was not feasible at that time due to limited resources. It wasn’t until 2019 that advancements in high-throughput DNA sequencing allowed scientists to pinpoint a genetic mutation responsible for the unique blood type.
The patient, a 54-year-old woman residing in Paris, inherited the “Gwada negative” blood type from both her parents, who carried the mutated gene. Peyrard emphasized that she is the only known individual in the world with this blood type, making her compatible only with herself.
Named after the patient’s Guadeloupean origins, the term “Gwada negative” has resonated with experts for its universal appeal. The discovery of this new blood group underscores the continuous evolution of transfusion science, with Peyrard and his team now seeking other individuals with a similar blood type to enhance patient care.
The identification of new blood groups through DNA sequencing presents a promising avenue for improving healthcare outcomes for individuals with rare blood types. As the EFS highlights, this breakthrough offers hope for enhanced treatment options and personalized care for patients in need.
© Agence France-Presse