27-06-2025
Doctors Found a New Blood Type and It Changes What We Thought We Knew
For decades, most of us thought blood types were simple: A, B, AB, or O—each with a positive or negative Rh factor. But that's just the surface.
Scientists now recognize 48 distinct blood type groups, and the newest one, just officially classified, belongs to exactly one person on Earth.
Meet 'Gwada negative,' the rarest blood type known to science, Live Science reported.
The story begins 15 years ago, when doctors in France drew blood from a woman with Caribbean ancestry from Guadeloupe, known locally as 'Gwada.' At the time, she was undergoing routine testing ahead of a surgery. But what her blood revealed was anything but routine.
Back in 2011, researchers noticed an unusual antibody. It took nearly a decade of genetic analysis and DNA sequencing to uncover the source: a previously unknown mutation that altered the structure of her blood in a way never seen before.
This month, the International Society of Blood Transfusion (ISBT) confirmed the discovery, officially designating 'Gwada negative' as the 48th recognized blood group.
According to Thierry Peyrard, a medical biologist with the French Blood Establishment (EFS), she's the only person known to carry it and the only person in the world she's compatible with for transfusions.
'Discovering new blood groups means offering patients with rare blood a better level of care,' the EFS said in a statement.
That's because while ABO-Rh typing is safe for most transfusions, rare blood groups can lead to life-threatening complications if not properly matched.
With over 600 known antigens on blood cells, there are theoretically millions of possible combinations. But until now, only 47 had been officially cataloged. Thanks to advances in gene sequencing, that number is growing quickly, so don't be surprised if more discoveries like 'Gwada negative' follow.
For one woman in France, her blood told a story no one else Found a New Blood Type and It Changes What We Thought We Knew first appeared on Men's Journal on Jun 26, 2025
