British Researchers Discover New Blood Group

A team of scientists from the United Kingdom's NHS Blood and Transplant (NHSBT) and the University of Bristol has discovered a new blood group, MAL, solving a 50-year-old mystery surrounding the AnWj blood group antigen. This breakthrough, recently published in Blood, elucidates the genetic background of this rare antigen, first identified in 1972, and could make it easier to identify and treat patients who lack it.

Researchers found that the AnWj antigen is carried on the Mal protein. While illness can cause some people to lose the AnWj antigen, inherited cases of the AnWj-negative phenotype are extremely rare. Using whole exome sequencing on five genetically AnWj-negative individuals, researchers confirmed that, in these cases, the participants lacked the antigen due to homozygous deletions in the MAL gene.

The team also confirmed that the Mal protein is responsible for binding AnWj antibodies, enabling the development of new tests to identify those at risk of transfusion complications.

“Resolving the genetic basis for AnWj has been one of our most challenging projects,” said Nicole Thornton, head of IBGRL Red Cell Reference at NHSBT. “There is so much work that goes into proving that a gene does actually encode a blood group antigen, but it is what we are passionate about, making these discoveries for the benefit of rare patients around the world.”