“Gwada negative”: a new blood type identified in a Guadeloupean woman

As early as 2011, a "very particular" and "unknown" antibody was found in this patient, but the resources at the time did not allow for further research, explained Thierry Peyrard, a medical biologist pharmacist, head of the EFS for the quality and safety of blood products and a researcher at Inserm.

Scientists were able to "unravel the mystery" from 2019, thanks to "very high-throughput DNA sequencing", which highlighted "a genetic mutation", he added.

The discovery of this new group "was made official at the beginning of June in Milan by the International Society of Blood Transfusion (ISBT)," the EFS announced on social media.

Now in her sixties, the patient was "54 years old, living in Paris" and was undergoing the usual tests before surgery when the unknown antibody was detected, Mr. Peyrard recalled.

"There is only one who is compatible with herself today in the world" for the moment, whereas for other rare blood types, a small group of people can be identified, such as siblings. This woman "is undoubtedly the only known case in the world," the specialist said.

"This blood type is inherited from her father and mother," who each had "the mutated gene." Like their parents, the patient's siblings "carried only one allele" and therefore did not have this blood type, which is declared "with the two identical genes."

The discovery led to the naming of "a new family, called PIGZ, which became the 48th blood group system in humans." The best-known system, ABO, dates back to 1900.