In early June, the International Society of Blood Transfusion (ISBT) officially announced the discovery of a new rare blood group called "Gwada negative," according to France 24. The Établissement français du sang (EFS), the French Blood Establishment, expressed satisfaction on social media about the finding.
A French woman of Guadeloupean origin has been identified as the only known carrier of this blood group. "Today, she is the only person in the world compatible with herself," said Thierry Peyrard, a pharmacist and medical biologist responsible for quality and safety of blood products at Établissement français du sang (EFS), the French Blood Establishment.
"Since 2011, a very particular and unknown antibody had been found in this patient during routine examinations, but the technical means of the time did not allow for further investigations," explained Peyrard. At that time, the resources available were insufficient to continue the research. The patient was 54 years old when the antibody was detected and is now in her sixties.
Advancements began in 2019 when scientists were able to "unravel the mystery" of the antibody thanks to "very high-throughput DNA sequencing." "This sequencing highlighted a genetic mutation," said Peyrard. The mutation was inherited from both of the woman's parents. The blood group manifests only when both identical genes are inherited, and her siblings, carrying only one copy of the gene, did not exhibit this blood type.
The name "Gwada negative" refers to the patient's Guadeloupean origin and "sounds good in all languages," according to Peyrard. "The name was very well received by specialists," he added. In French usage, Guadeloupe is often affectionately called "Gwada," and "negative" signifies the absence of a specific antigen in her red blood cells. The terminology contributed to its quick establishment among experts.
The discovery of the new blood group, associated with a mutation in the PIGZ gene, has led to the naming of a new family called PIGZ, making it the 48th blood group system in humans. In recent years, discoveries of new blood groups have accelerated, with advancements made possible by very high-throughput DNA sequencing starting in 2019. "What is fascinating is that this discovery has not only functional results. It allows for a better understanding of pathologies," Peyrard noted.
Identifying possible donors with the "Gwada negativo" phenotype will be important, particularly in populations with ancestry similar to that of the original patient. Peyrard and his team are currently developing a special protocol with the hope of finding other people with the same blood group, "especially in Guadeloupe, among blood donors." It will require active search campaigns and the creation of international rare donor registries, as is already done with other uncommon blood groups.
Blood compatibility is essential to avoid immunological reactions in transfusions. An incompatibility between donor and recipient can have serious consequences, including death. "If she needs a blood transfusion, it will be necessary to find a compatible donor," emphasized Peyrard. For other rare blood groups, there are usually small groups of compatible people, such as siblings, but in this case, the woman is "the only known case in the world."
The most well-known blood group system, ABO, dates back to 1900, and the most familiar blood groups are A+, A−, B+, B−, AB+, AB−, and O+. To date, nearly 400 different subgroups have been identified. The identification of new blood groups underscores the importance of biological compatibility and offers new perspectives in various medical fields, including oncology, neurology, and rheumatology.
The EFS highlighted the importance of each new blood group in improving the supply of patients with rare blood types. Timely identification of people with rare blood groups is extremely important to provide necessary assistance in case of emergency. "It's also important for women who are expecting children: if the mother has a rare blood type, she can produce an antibody that can target her child," Peyrard explained.
Produced with the assistance of a news-analysis system.