Or maybe it would be better put to say they’ve been “identified.”

You thought you knew your blood type. You might want to rethink that. If I ask you, you probably would answer: A, B, AB or O. If you’re really on top of things, you might even know if you’re Rhesus positive or negative.

Have you ever heard of the Langereis blood type? Or the Junior blood type?

According to Science Daily, several ethnic populations are at risk, the Japanese being one of them, of having these admittedly rare blood types.

In the February issue of Nature Genetics, a scientist and his colleagues report on their discovery of two proteins on red blood cells responsible for these lesser-known blood types. Perhaps the most interesting part of the article listed 28 blood types in addition to the ones we know about:

“Beyond the ABO blood type and the Rhesus (Rh) blood type, the International Blood Transfusion Society recognizes 28 additional blood types with names like Duffy, Kidd, Diego and Lutheran. But Langereis and Junior have not been on this list. Although the antigens for the Junior and Langereis (or Lan) blood types were identified decades ago in pregnant women having difficulties carrying babies with incompatible blood types, the genetic basis of these antigens has been unknown until now.”

Scientists admit that both are rare, but could cause deadly results in the case of transfusions and organ transplants.