Scientists have confirmed the existence of an extraordinary new blood type, "Gwada negative," marking the 48th recognized human blood group. The discovery emerged from a routine blood sample taken over 15 years ago from a woman in Guadeloupe, a French Caribbean territory.

Initial screening in 2011 revealed an unusual antibody, but without the tools to investigate further. It wasn’t until 2019, when high-throughput DNA sequencing was applied, that researchers at France’s Établissement Français du Sang (EFS) pinpointed a unique genetic mutation - now officially acknowledged by the International Society of Blood Transfusion in early June 2025.

According to EFS biologist Thierry Peyrard, the woman is currently the only known person with this blood type, meaning she is only compatible with herself in transfusion settings. The mutation affects the PIGZ gene, altering red blood cell antigens and raising vital considerations for transfusion compatibility and healthcare readiness.

The EFS team hopes to screen other donors - especially from Guadeloupe - to find more individuals with this rare type. This breakthrough deepens medical understanding of blood diversity and enhances future patient care.