Rh null individuals have no Rh antigens (no Rh or RhAG) on their red blood cells. As a consequence of the absence of Rh antigens, Rh null red blood cells also lack LW and Fy5 and show weak expression of S, s, and U antigens. Red blood cells lacking Rh/RhAG proteins have structural abnormalities (such as stomatocytosis) which can result in hemolytic anemia. Rhnull blood was first described in 1961, in an Aboriginal Australian woman. Until then, doctors had assumed that an embryo missing all Rh blood-cell antigens would not survive, let alone grow into a normal, thriving adult. By 2010, nearly five decades later, some 43 people with Rhnull blood had been reported worldwide. Researchers seeking to unravel the … Continue reading What is Rh null?