Researchers Finally Solve 50-Year-Old Blood Group Mystery

Researchers at Lund University found a previously missed DNA switch that changes how transcription factors bind and regulate blood group antigen expression.

The discovery helps explain why people with the same blood type can produce very different levels of blood group molecules, including the rare Helgeson variant.

The study, published in Nature Communications, points to a new genetic mechanism affecting CR1 and other blood group antigens.

By revealing antigen differences that standard blood tests can overlook, the finding could improve transfusion matching and patient safety.