Fig. 1: Phenotypic and dysmorphic features of patient 1 (A and B),...

Only One Person On Earth Has This Blood Type. What Is 'Gwada Negative'?

A woman from the French Caribbean territory of Guadeloupe has been confirmed as the only known person in the world to possess a newly classified blood group — now officially recognised as the 48th blood group system.

The new blood group has been named "Gwada negative", after a local nickname for the islands of Guadeloupe.

The discovery was announced by France's national blood service, Établissement français du sang (EFS), following its formal recognition by the International Society of Blood Transfusion (ISBT) at its congress in Milan.

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The ISBT had previously identified 47 unique blood group systems. This development comes more than a century after Austrian-American biologist Karl Landsteiner first identified the ABO system in 1901, a milestone that would later earn him a Nobel Prize.

How 'Gwada negative' was discovered

The woman in question, now 68 years old and living in Paris, first drew the attention of medical researchers in 2011. At the time, she was undergoing routine pre-surgical blood tests.

Initial laboratory tests failed to classify her blood using any known blood typing methods. An atypical antibody was identified, and her blood could not be matched within existing systems.

A "very unusual" antibody was first found in the patient in 2011, Thierry Peyrard, a medical biologist from EFS, who has played a key role in the study, told AFP.

However, at the time of the initial tests, the tools and technology available were insufficient to explore the anomaly further.

The case remained unexplained for nearly eight years, until 2019, when scientists at EFS returned to her sample using a more advanced diagnostic tool — high-throughput DNA sequencing.

This technology enabled researchers to conduct a deeper genetic investigation, ultimately revealing a mutation in the PIGZ gene, which alters how specific proteins anchor themselves to red blood cells.

The woman was confirmed to have inherited the condition from both her parents, who each carried a version of the mutated gene. This made her the only known person on Earth to have this specific blood group.

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"She is the only person in the world who is compatible with herself," said Peyrard.

He noted that the name "Gwada negative" was chosen in reference to the patient's Guadeloupean origin and also because "it sounds good in all languages," making it a suitable term for global usage among the scientific and medical communities.

What makes blood types so complex

Though most people know their blood type as A, B, AB, or O — combined with a positive or negative Rh factor — these are just the best-known components of a vast and intricate system.

Human red blood cells carry more than 600 different antigens, and each unique combination of these can result in a new blood type.

For this reason, the ISBT recognises blood group systems rather than individual blood types. Each system is defined by the genetic and serological properties that influence the expression of antigens.

The ABO and Rh systems are the most clinically important, especially for transfusions, but over the years, dozens of others have been identified, including rare ones that affect transfusion compatibility and immune response.

The addition of Gwada negative follows previous rare group discoveries such as the "Er" system, which was recognised in 2022.

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Scientific progress in gene sequencing, particularly high-throughput genomic tools, has accelerated the pace of discovery in recent years. According to experts, more new blood groups may be identified annually as sequencing technologies become more widespread and affordable.

What this means for rare blood group carriers

Understanding blood types is critical in transfusion medicine. When blood from a donor carries antigens that are not recognised by the recipient's immune system, it can trigger a dangerous immune reaction, which can be life-threatening.

The ABO-Rh system offers transfusion compatibility in 99.8 per cent of cases, but patients with rarer blood types face greater risk and more limited donor options.

The EFS highlighted this point in its public statement: "Discovering new blood groups means offering patients with rare blood types a better level of care."

Although millions of theoretical blood types are possible based on antigen variation, only 48 blood group systems have met the rigorous genetic and serological criteria to be recognised by the ISBT.

Every addition to this list not only advances the scientific understanding of human genetics but also enhances the safety and efficacy of transfusions for rare cases.

In the United States alone, the Centers for Disease Control and Prevention (CDC) reports that more than 14 million units of blood are transfused annually. Accurate typing and identification are essential to ensure those transfusions are both safe and effective.

STORY CONTINUES BELOW THIS AD Why this puts the woman with 'Gwada negative' in a unique position

The woman with Gwada negative blood is unique in more ways than one.

Unlike other rare blood types that may have small numbers of known carriers, she is the only confirmed person worldwide with this classification, making her completely incompatible with any blood donor currently known to science — except herself.

This reality poses major challenges should she ever require a transfusion. Her genome sequencing has been archived, and researchers are now focused on locating other potential carriers, particularly among blood donors from Guadeloupe and surrounding regions.

Because blood types are inherited, populations with shared ancestry may be the most likely sources of other cases.

The blood group's formal recognition by the ISBT not only gives it a place in global transfusion protocols, but also encourages international collaboration to identify other carriers and develop strategies for rare donor recruitment.

With inputs from agencies

End of Article

Deadly Blood Cancer Can Now Be Detected Early With Blood Test: Study

A team of Israeli and American scientists have developed a groundbreaking blood test that may soon revolutionize the early detection of leukaemia and other blood-related disorders. The test, which analyzes a simple blood sample, could eliminate the need for invasive bone marrow biopsies currently used in diagnosis.

Published in the prestigious journal Nature Medicine, the study was led by researchers from the Weizmann Institute of Science in Israel. The team focused their work on identifying early indicators of myelodysplastic syndrome (MDS), an age-related condition in which blood-forming stem cells fail to develop correctly. MDS is particularly dangerous as it can lead to severe anaemia and progress into acute myeloid leukaemia (AML), a fast-growing type of blood cancer prevalent among adults.

Currently, diagnosing MDS requires a painful and intrusive procedure — bone marrow sampling — which involves drilling into the pelvic bone under local anaesthesia. For many patients, especially older adults, this process is uncomfortable and distressing.

The new research offers a promising alternative. The scientists discovered that rare blood-forming stem cells, which occasionally escape from the bone marrow and circulate in the bloodstream, carry crucial genetic clues about the early development of MDS. Using advanced single-cell genetic sequencing techniques, the researchers successfully decoded the information contained within these rare cells — all from a routine blood draw.

One of the most remarkable findings was that these circulating stem cells not only provide early markers of disease but also appear to act as biological "clocks" that reflect a person's chronological aging.

"These stem cells give us insights not only into early-stage disease but also into how aging progresses differently in men and women," explained Dr. Nili Furer of the Weizmann Institute. "We found that in males, the changes in these cells occur earlier than in females, potentially explaining the higher incidence of blood cancers among men."

The study holds significant promise for the future of cancer diagnostics. By replacing an uncomfortable and invasive procedure with a simple blood test, early detection becomes more accessible and patient-friendly.

Furthermore, the researchers believe this breakthrough method could be adapted to detect other age-related blood disorders beyond MDS and AML. A large-scale international clinical trial is already underway to validate the effectiveness of the blood test across multiple medical centers worldwide.

If successful, this new method could pave the way for more accurate, less invasive, and earlier diagnoses of life-threatening blood cancers, ultimately improving outcomes and quality of life for countless patients.

ICMR Creates Rare Blood Donor Database To Aid High-risk Patients

In a landmark initiative, the National Institute of Immunohaematology, Mumbai, has launched India's first national rare blood donor registry to support patients with rare blood types who require frequent transfusions, particularly those with thalassemia or sickle cell disease

The National Institute of Immunohaematology in Mumbai under the India Council of Medical Research has for the first time created a national 'rare blood donor registry' for patients with rare and uncommon blood types who need frequent transfusion especially in conditions such as thalassemia and sickle cell disease.

The ICMR-NIIH is now in talks with the Director General of Health Services (DGHS) so that the rare donor registry portal can be integrated with e-Raktakosh, a platform which currently provides information about blood availability, Dr Manisha Madkaikar, Director of ICMR-Centre for Research Management and Control of Haemoglobinopathies (CRHCM) in Nagpur said.

The integration will help people with rare blood groups easily trace blood banks and procure blood. It will also assist the blood banks manage their stock and donors through a centralised system.

India, with a population of more than 142 crore, has over 4,000 licensed blood banks, according to the Central Drug Standard Control Organisation (CDSCO).

India relies heavily on transfusions due to a higher prevalence of blood diseases and complications during pregnancy, Dr Madkaikar said.

"Thalassemia itself contributes to 1 to 1.5 lakh patients who require recurrent transfusions," she said.

Rising demand spurs integration with e-Raktakosh

Additionally, with more than 1,200 road accidents occurring every day in India, and with every year 60 million surgeries, 240 million major operations, 331 million cancer-related procedures, and 10 million pregnancy complications, a serious call for blood transfusion is recognised, she said.

In majority of blood banks in India, only ABO and RhD are antigens matched prior to cross-matching for issuing of red blood cell components. However, the International Society of Blood Transfusion (ISBT) has recognised more than 360 antigens in 47 blood group systems. Blood banks do not perform testing of these minor blood group antigens routinely, explained Dr Madkaikar.

"As a result, a mismatch of minor antigens between donor and patient blood group (BG) profiles can lead to red cell alloimmunization (1-3 per cent in the general population, 8-18 per cent in thalassaemic patients). About 25 per cent of all immunized patients have been reported to receive unsatisfactory transfusion support due to presence of multiple antibodies or antibodies to high frequency antigens (HFA)," she said.

Rare blood groups are those which lack HFA (1:1000 or less), or are negative for a combination of common antigens, or have a null phenotype.

Registry set for national expansion

"Meeting a demand for rare blood supply is challenging and time consuming for such patients. The need of a patient for rare blood can be the start of a series of events that may extend beyond the local blood centre and become a national or even an international search," Dr Madkaikar said.

To overcome this challenge, an inventory of extensively typed blood donors and rare blood type donors is required, she said.

For this, internationally 27 countries have operational national rare donor registry programmes. India, however, is not a contributor country, she said.

In 2019, however, ICMR-NIIH was granted Centre of Excellence project under the aegis of ICMR, where an initiative was taken to screen 4,000 'O' group regular blood donors for all clinically important antigens using high throughput molecular assays, from four different regions of India in collaboration with the big blood banks from KEM Hospital Mumbai, PGIMER Chandigarh, MCH Kolkatta and JIPMER Puducherry.

"More than 600 donors negative for combination of antigens were identified along with 250 very rare blood group donors. The registry also includes 170 Bombay blood group donors, which is the commonly required rare blood type in India (approx 120-150 units/year). To access this inventory (ICMR-Rare Donor Registry of India (RDRI)), a web-based portal has been developed for systematic requisition and provision of blood to patients on time," Dr Madkaikar said.

"There is a plan to integrate this rare donor registry with e-Raktakosh of DGHS so that all the blood banks can contribute their rare donors and help in expansion of the registry. Last month we held a meeting with the DGHS," she said.

Published on June 21, 2025

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