A ''New'' Blood Group Antigen Associated with S and s

Abstract. The serum of a Papuan blood donor contains an antibody to a previously unreported red cell antigen, provisionally called Z, and closely associated with S or s. In both European and Melanesian populations Z is more common than S, because S-positive bloods rarely lack Z, while S-negative bloods not uncommonly possess it. Z is inherited as a dominant character.