While blood types are often reduced to the four most common (O, A, B and AB), there are actually hundreds of them, some of which are particularly rare. A new name has just been added to this list: blood type MAL. As reported by the BBC, it was discovered by a British research team led by scientists from NHS Blood and Transplant (NHSBT) in South Gloucestershire and supported by the University of Bristol.
The researchers identified the genetic background of the AnWj blood group antigen, which was discovered in 1972 but was poorly understood until now. According to the NHSBT, over 99.9% of humans are AnWj positive. Only a handful of individuals are therefore AnWj negative, either due to disease or through hereditary causes.
Extremely rare cases
The study also allowed the development of new genotyping tests aimed at identifying these rare individuals and thus reducing the risks of complications caused by a transfusion. Indeed, AnWj-negative individuals may not tolerate a transfusion of AnWj-positive blood.
“The genetic background of AnWj has been a mystery for over 50 years, and it’s a mystery that I’ve personally been trying to solve for almost 20 years. This represents a huge achievement and the culmination of a long team effort to finally establish this new blood group system and be able to provide the best care for rare but important patients,” said Louise Tilley, one of the study’s lead authors.
