Doctors Discover New Blood Type—And Only One Person Has It

The following test is reprinted with the permission of The conversation, an online publication covering the latest research.

In a routine blood test which has become extraordinary, French scientists have identified the most recent and rare the world’s blood group. The only known carrier is a woman from Guadeloupe whose blood is so unique that doctors could not find a single compatible donor.

The discovery of the 48th recognized blood group, called “Gwada-Negative”, began when the woman’s blood plasma reacted against each sample of potential donor tested, including those of her own brothers and sisters. Therefore, it was impossible to find an appropriate blood donor for her.

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Many people know their blood group – A, B, AB or O – as if they are positive or negative HR. But these familiar categories (these more “positive” or “negative” letters) represent only two of the dozens of blood group systems which determine the compatibility of transfusions. Each system reflects subtle but crucial differences in proteins and sugars coating our red blood cells.

To resolve the mystery of the incompatible blood of the Guadelopian woman, scientists turned to a state -of -the -art genetic analysis. Using sequencing in whole exome – a technique that examines the more than 20,000 human genes – they discovered a mutation in a gene called Pigz.

This gene produces an enzyme responsible for adding a sugar specific to a significant molecule on cell membranes. The missing sugar modifies the structure of a molecule on the surface of the red blood cells. This change creates a new antigen – a key characteristic which defines a blood group – resulting in a whole new classification: positive (having the antigen) or -negative (the missing).

Using gene editing technology, the team confirmed its discovery by recreating the mutation in a laboratory. The red blood cells of all tested blood donors are therefore gwada-post-positive and the Guadélopeen patient is the only known person in negative gwada on the planet.

The implications of the discovery extend beyond blood transfusions. The patient suffers from a slight intellectual impairment, and tragically, she has lost two babies at birth – results that can be linked to her rare genetic mutation.

The enzyme produced by the Pigz gene operates at the final stage of building a complex molecule called GPI (glycosylphosphatidylinositol). Previous research has shown that people with faults in other enzymes necessary for GPI assembly can encounter neurological problems ranging from delay in crisis development. Mortinagances are also common in women with these inherited disorders.

Although the Caribbean patient is so far the only person in the world with this rare blood group, neurological conditions, including development delay, intellectual disability and convulsions, have been noted in other people with defects in the necessary enzymes in the GPI assembly chain.

The discovery of Gwada highlights the wonders and challenges of human genetic diversity. Blood groups have partially evolved as protection against infectious diseases (many bacteria, viruses and parasites use blood group molecules as entry points into cells). This means that your blood group can influence your sensitivity to certain diseases.

But extreme rarity creates medical dilemmas. French researchers recognize that they cannot predict what would happen if the incompatible blood of Gwada was transfused to the Guadeoupian woman. Even if other negative people from Gwada exist, they would be extremely difficult to locate. It is also not known if they can become blood donors.

This reality points to a futuristic solution: blood cells cultivated in the laboratory. Scientists are already working on the growth of red blood cells from stem cells that could be genetically modified to correspond to ultra-rare blood groups. In the case of Gwada, researchers could artificially create the red blood cells of negative Gwada by mutilating the Pigz gene.

A growing field

Gwada joins 47 other blood group systems recognized by the International Blood Transfusion Company. Like most of these blood group systems, it was discovered in a hospital laboratory where technicians were trying to find compatible blood for a patient.

The name reflects the roots of the Caribbean of the case: Gwada is slang for someone Guadeloupe, giving this blood group both scientific relevance and cultural resonance.

As genetic sequencing becomes more advanced and widely used, researchers expect to discover rarer blood groups. Each discovery expands our understanding of human variation and is raising new challenges for transfusion and other types of personalized medicine.

This article was initially published on The conversation. Read it original article.