Gwada Negative: All about the world's rarest 48th blood type found in just one person

Time of India

3 days ago

A French woman from Guadeloupe, has been identified as the only known carrier of a new blood type, "Gwada negative," discovered 15 years after her blood sample was taken for routine surgery preparation, and officially recognized by the International Society of Blood Transfusion (ISBT) in June, marking the 48th
blood group
system. The French Blood Establishment (EFS) announced the discovery, highlighting its importance for patients with rare blood types, made possible through advanced
DNA sequencing
that revealed a genetic mutation.
The ABO-Rh system is a method that helps medical professionals safely perform blood transfusions. The French Blood Establishment (EFS) has identified the 48th blood type group, known as 'Gwada negative,' from a blood sample drawn some 15 years ago.
The discovery was officially recognised in early June in Milan by the International Society of Blood Transfusion (ISBT). The scientific association had until now recognised 47 blood group systems.
Most people are familiar with the four broad human blood types —A, B, AB, and O—and it's likely they may even know that they come in positive or negative varieties. Humans theoretically contain millions of different blood types, as there are more than 600 antigens that have been identified on human blood cells.
The International Society of Blood Transfusion (ISBT) only recognizes 47 distinct blood type groups, with the latest being added just last year after a 50-year-long mystery. According to a press statement published on LinkedIn by the French Blood Establishment (EFS), a 48 th member has officially joined.
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Some 15 years ago, researchers received blood from a French woman originating from the Caribbean island of Guadeloupe, colloquially referred to as 'Gwada.' The patient drew blood while undergoing routine tests before surgery.
An unusual antibody associated with this blood was discovered in 2011, but it wasn't until 2019 that DNA sequencing found that a genetic mutation was responsible for the unique blood type, which was officially recognized by the ISBT this month.
Thierry Peyrard, a medical biologist at the EFS involved in the discovery, told AFP that a "very unusual" antibody was first found in the patient in 2011. Resources at the time did not allow for further research. Scientists were finally able to unravel the mystery in 2019 thanks to "high-throughput DNA sequencing", which highlighted a genetic mutation, Peyrard said.
The patient, who was 54 at the time and lived in Paris, was undergoing routine tests before surgery when the unknown antibody was detected, Peyrard said.
The researchers named the group 'Gwada negative,' after the patient's homeland, and confirmed that the woman inherited the blood type from her parents, who each contained the mutated gene.
'[This] is undoubtedly the only known case in the world,' Thierry Peyrard, a medical biologist at EFS, told Agence France-Presse (AFP).
'She is the only person in the world who is compatible with herself.'
Peyrard said the woman inherited the blood type from her father and mother, who each had the mutated gene.
The name "Gwada negative", which refers to the patient's origins and "sounds good in all languages", has been popular with the experts, said Peyrard.
Its immensely important to know the antigen make-up of your blood before undergoing blood transfusions , as mismatch can trigger a life-threatening immune response. Essentially, your body thinks the antigens attached to the foreign blood cells are invaders.
Although there are potentially millions of blood types, transfusions made with blood that matches your type according to the well-established ABO-Rh type system have a 99.8 percent chance of success. This is because your body's immune response doesn't attack all antigens equally, so even if there are some differences, the transfusion will likely be a success.
However, it's still important to identify these ultra-rare blood types so that life-threatening immune responses can be avoided.
Although the current number of blood groups sits at 48, that likely won't be the last count. Advancements in gene sequencing have supercharged the discovery of these blood groups. For example, the 44 th member of this group, known simply as 'Er,' was discovered in 2022 , meaning that scientists are currently discovering more than one new blood group a year.
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