Rh- blood is the result of a gene deletion. The gene in question is the D antigen from the Rhesus Blood Group System There are many blood group systems and the 2 most important ones are the ABO Blood Group System and the Rhesus Blood Group System There are more than 50 antigens that are known of in the Rhesus Blood Group System and the D antigen is the most important one as its impact on pregnancies is the most significant Being Rh- means being D negative, meaning: you test negative for the presence of the D antigen. If the D antigen is missing, you are Rh- negative If all antigens are missing, you are Rh null, which is extremely … Continue reading Where does Rh negative blood come from?