New Blood Group Discovered After a 50-Year Mystery

Researchers from the UK and Israel have identified a new human blood group system called the MAL blood group, a significant scientific achievement following a unique case from 1972. The mystery began when a pregnant woman's blood sample was found to lack a surface molecule present on all other known red blood cells at the time. This absence remained unexplained for nearly five decades.

The findings were published in September 2024, marking the culmination of nearly 20 years of research led by UK National Health Service hematologist Louise Tilley. The MAL blood group adds to the already extensive list of blood group systems recognized, which are crucial for safe blood transfusions. Mismatches can lead to severe reactions, making this discovery significant for patient care, especially for those with rare blood types.

The MAL group is characterized by the absence of the AnWj antigen, which is present in over 99.9 percent of the population. Tilley's research team identified a genetic mutation responsible for creating an AnWj-negative blood type in three patients, indicating that other factors may also suppress this antigen. The study provides a pathway for further testing, allowing potential identification of underlying health issues in those with the rare blood type.

This new blood group highlights the intricate variations in human blood and the importance of continued research to enhance blood transfusion safety and patient care.