Scientists identify genetic cause of rare AnWj blood group after 50-year search

Researchers led by NHS Blood and Transplant in Bristol, with the International Blood Group Reference Laboratory and University of Bristol, traced the AnWj red-cell antigen first described in 1972 to its gene, defining a new MAL blood group system. Over 99.9% of people are AnWj-positive; the finding should help find the rare negative patients and donors and reduce dangerous transfusion reactions.