After 50 years, this strange molecular absence finally led researchers from the UK and Israel to describe a new blood group system in humans.
“It represents a huge achievement, and the culmination of a long team effort, to finally establish this new blood group system and be able to offer the best care to rare, but important, patients,” UK National Health Service hematologist Louise Tilley says, after nearly 20 years of personally researching this bloody quirk.
While we’re all more familiar with the ABO blood group system and the rhesus factor (that’s the plus or minus part), humans actually have [many different blood group systems](https://en.wikipedia.org/wiki/Human_blood_group_systems) based on the wide variety of cell-surface proteins and sugars that coat our blood cells.
Our bodies use these antigen molecules, amongst their other purposes, as identification markers to separate ‘self’ from potentially harmful not-selves.
If these markers do not match up when receiving a blood transfusion, this life-saving tactic can cause reactions or even end up being fatal.
Most major blood groups were identified early in the 20th century. Many discovered since, like the Er blood system first described by researchers in 2022, only impact a small number of people. This is also the case for the new blood group.
“The work was difficult because the genetic cases are very rare,” explains Tilley.
Previous research found more than 99.9 percent of people have the AnWj antigen that was missing from the 1972 patient’s blood. This antigen lives on a myelin and lymphocyte protein, leading the researchers to call the newly described system the MAL blood group.
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Summary of the article by Tessa Koumoundouros:
When a pregnant woman had her blood sampled back in 1972, doctors discovered it was mysteriously missing a surface molecule found on all other known [red blood cells](https://www.sciencealert.com/red-blood-cells-play-a-much-greater-role-in-our-immune-system-than-we-thought) at the time.
After 50 years, this strange molecular absence finally led researchers from the UK and Israel to describe a new blood group system in humans.
“It represents a huge achievement, and the culmination of a long team effort, to finally establish this new blood group system and be able to offer the best care to rare, but important, patients,” UK National Health Service hematologist Louise Tilley says, after nearly 20 years of personally researching this bloody quirk.
While we’re all more familiar with the ABO blood group system and the rhesus factor (that’s the plus or minus part), humans actually have [many different blood group systems](https://en.wikipedia.org/wiki/Human_blood_group_systems) based on the wide variety of cell-surface proteins and sugars that coat our blood cells.
Our bodies use these antigen molecules, amongst their other purposes, as identification markers to separate ‘self’ from potentially harmful not-selves.
If these markers do not match up when receiving a blood transfusion, this life-saving tactic can cause reactions or even end up being fatal.
Most major blood groups were identified early in the 20th century. Many discovered since, like the Er blood system first described by researchers in 2022, only impact a small number of people. This is also the case for the new blood group.
“The work was difficult because the genetic cases are very rare,” explains Tilley.
Previous research found more than 99.9 percent of people have the AnWj antigen that was missing from the 1972 patient’s blood. This antigen lives on a myelin and lymphocyte protein, leading the researchers to call the newly described system the MAL blood group.
Read the full peer-reviewed paper here: [https://ashpublications.org/blood/article-abstract/doi/10.1182/blood.2024025099/517404/Deletions-in-the-MAL-gene-result-in-loss-of-Mal?redirectedFrom=fulltext](https://ashpublications.org/blood/article-abstract/doi/10.1182/blood.2024025099/517404/Deletions-in-the-MAL-gene-result-in-loss-of-Mal?redirectedFrom=fulltext)