Maternal Sensitization Due to Bi

Clarification of the pathogenesis of hemolytic disease of the newborn and the increasing use of blood transfusions have provided the stimulus to discovery of many new blood groups. Ten independent, major blood group systems are now known. 1-3 In addition, a number of and low incidence antigens have been described. 2 The purpose of this paper is to report a private red cell antigen, to our knowledge previously undescribed. The family has given permission to employ the surname, Biles, and the abbreviation Bi has been tentatively employed to designate the gene, and Bi the red cell antigen. The corresponding antibody has been designated anti- Bi . Clinical Information Mr. W.L.B., the propositus, is a 29-year-old white man of Welsh-Irish descent who has remained in excellent health. In 1952, at age 19, his wife, Mrs. B.J.B., delivered a full-term normal female infant without complications. This child experienced a normal neonatal