When we think of blood groups, the standard types, that is, A, B, AB, and O, typically come to mind. However, a recent scientific breakthrough has unveiled a blood group so rare and unusual that it has astonished the global medical community. Known as 鈥楪wada Negative鈥, this newly identified blood group has been found in just one person on the planet and was officially recognised at the International Society of Blood Transfusion (ISBT) conference held in Milan in June 2025.
What Is 鈥楪wada Negative鈥?
鈥楪wada Negative鈥 is far from an ordinary blood group. It has now been recognised as the 48th official blood group system in the world, following its inclusion by the ISBT. The discovery was made by the French Blood Establishment (脡tablissement Fran莽ais du Sang, EFS) and pertains to a 68-year-old woman from Guadeloupe.
This blood group falls under the EMM-negative system. EMM is a high-frequency antigen typically found on the red blood cells of nearly all individuals. Its complete absence in this woman鈥檚 blood has left scientists both intrigued and perplexed.
The 15-Year Journey To Discovery
The origins of this discovery date back to 2011, when the woman, originally from Guadeloupe and residing in Paris, underwent a routine blood test prior to surgery. During the screening, doctors detected an unidentified antibody that did not match any known blood group systems.
At the time, technological limitations prevented further classification. It wasn鈥檛 until 2019, with the use of Next Generation Sequencing (NGS) technology, that scientists were able to reanalyse the preserved sample and identify the unique properties of her blood.
Why Is This Blood Group So Rare?
The term 鈥楪wada Negative鈥 refers to the total absence of the EMM antigen in the woman鈥檚 red blood cells. This is extraordinarily rare, as EMM is considered a high-incidence antigen, present in almost all humans. Her condition is medically exceptional.
According to Dr Thierry Peyrard, chief biologist at EFS, the woman inherited mutated genes from both her mother and father. He noted that she is compatible only with her own blood, meaning no existing donor can safely provide her with a transfusion.
Impact Of The Medical Discovery
This finding has significant implications beyond academic and scientific interest. It offers renewed hope to individuals living with rare blood disorders.
In a statement, the EFS remarked: 鈥淓ach new blood group system strengthens our ability to provide tailored care, particularly for patients with complex or uncommon transfusion needs.鈥