An unidentified woman from Guadeloupe in the Lesser Antilles has the rarest blood type on earth. The 68-year-old is the only known member of the blood group “Gwada negative.” The moniker comes from the colloquial name for the French Caribbean island the woman calls home. Scientists with the French Blood Establishment, who discovered the blood type, were introduced to the woman in 2001 when she was living in Paris and undergoing routine blood tests in preparation for surgery. Doctors were unable to identify her blood type or any matches for it. DNA analysis wasn’t advanced enough at that time to explore the case further, but in 2019 researchers utilized the next-generation technology to sequence the patient’s entire genome. Research revealed a mutation in the gene PIGZ, which affects how proteins anchor to the surface of blood cells. The team determined that the woman inherited her unique blood profile from her parents, as both carried the mutated gene. People with AB blood have A and B antigens, meaning they can receive blood from any donor. Meanwhile, type O blood has no antigens, meaning patients with this type can only receive blood from fellow type O donors. Gwada negative is now recognized as an official blood type, but that means that the only person in the world who has it can’t receive blood from anyone.
