A landmark international study has identified a new blood group system, unveiled after more than five decades of investigation. Researchers from the United Kingdom and Israel describe the MAL blood group, a finding sparked by a puzzling case from 1972. National Health Service hematologist Louise Tilley calls the discovery “a huge achievement,” marking the culmination of years of teamwork.
In 1972, a pregnant patient’s blood sample lacked a surface molecule once thought universal on red blood cells. It took over 50 years to recognize this anomaly as a distinct blood group system. The 2024 study decoded the genetic basis of this type, AnWj-negative, identifying mutations in the MAL genes. This work deepens our understanding of human blood diversity and could influence how some patients receive transfusions.
Blood groups matter because antigens on red blood cells guide the immune system in recognizing foreign cells. While ABO and Rh are the most familiar systems, many others exist, each defined by particular proteins and sugars on the cell surface. Compatibility is crucial in transfusions to prevent potentially fatal reactions.
The MAL system is particularly rare, making genetic confirmation challenging. Earlier research suggested the AnWj antigen is present in more than 99.9 percent of people, with the 1972 case lacking it. The AnWj-negative trait arises when both MAL gene copies carry mutations. The MAL protein relates to cell membrane stability and transport, underscoring its biological significance.
Researchers demonstrated a key linkage by inserting a normal MAL gene into AnWj-negative cells, which restored the AnWj antigen. This experiment confirmed the genetic basis of the new blood group. The work also highlights how single-gene changes can have meaningful impacts on blood typing and compatibility.
From a Thai standpoint, the discovery carries important public health implications. Understanding MAL mutations could improve genetic screening to determine whether AnWj-negative status is hereditary or due to other conditions. In Thailand, where regional genetic diversity influences medical care, such insights are particularly valuable.
Looking ahead, hospitals could adopt refined genetic testing protocols to diagnose rare blood conditions more reliably. Transfusion guidelines may need updates to reflect this new blood group and ensure safe, compatible blood supplies.
Thai medical institutions might increasingly emphasize genetic screening and public education about blood typing. Participation in global research remains essential, allowing Thailand to contribute to and benefit from major scientific advances.
This work was published in Blood, illustrating how patient perseverance and cross-border collaboration can reshape our understanding of human biology.