‘Gwada negative’: French scientists discover world’s rarest blood type

A woman from Guadeloupe has become the only known person in the world with a newly discovered blood group, which French scientists have named “Gwada negative.”

The French Blood Establishment (EFS) announced the rare discovery this week, saying it was officially recognised by the International Society of Blood Transfusion (ISBT) in Milan earlier this month. The finding brings the total number of recognised human blood group systems to 48.

The woman, now in her late 60s and living in Paris, first raised scientists’ curiosity in 2011 when a “very unusual” antibody was found during routine pre-surgery tests. But it wasn’t until 2019 that researchers were able to confirm the discovery using high-throughput DNA sequencing.

“She is the only person in the world who is compatible with herself,” said EFS expert Thierry Peyrard, adding that the woman inherited the rare mutation from both parents.

Nicknamed “Gwada negative” in reference to the woman’s Caribbean origins, the blood type may help improve treatment for others with rare or unknown blood groups.

“Discovering new blood groups means offering patients with rare types a better level of care,” said the EFS.

Scientists are now hoping to identify other carriers of the same gene mutation.

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