Scientists Have Discovered a New Blood Type:
The world’s rarest blood type was just discovered. Only one person has it, a 68-year-old woman from Guadeloupe, a French island in the Caribbean.
Scientists have named the blood type “Gwada negative,” after the local nickname for her home island. This is now officially the 48th known blood group system in the world, as confirmed by the International Society of Blood Transfusion in June 2025.
The discovery started back in 2011 when doctors in Paris found unusual results during the woman’s pre-surgery blood tests. They couldn’t match her blood to any known type. At the time, they didn’t have the technology to figure it out. In 2019, they used advanced DNA sequencing and found a rare mutation in a gene called PIGZ, which changes how certain proteins appear on red blood cells. Because of this unique mutation, her blood doesn’t match anyone else’s—scientists say she’s the only person in the world who is “compatible with herself.” Blood types are based on molecules on the surface of red blood cells, and your immune system reacts if it encounters a type it doesn’t recognize. The most common systems are ABO and Rh (like A+, B-, O+, etc.), but there are many others. Rare types like Gwada negative can cause serious problems during transfusions, especially if doctors can’t find a matching donor. That’s why this discovery matters: it helps improve care for people with rare blood. Researchers now want to check if anyone else, especially in Guadeloupe, shares this blood type. Finding more carriers would make it easier to treat people safely in medical emergencies.
Source https://www.popularmechanics.com/science/health/a65161270/gwada-negative-48-blood-group/