The Rh blood group antigen e is of high incidence and has many epitopes. Partial expression may occur, more commonly in black persons. Individuals with e variant phenotypes can make antibodies to epitopes they lack. While some of these antibodies may be specific for an antigen, e.g., hrB, others, like anti-Rh17 (anti-Hro), show broader specificity, compatible only with D–– and Rhnull red blood cells (RBCs). Anti-Rh17 in persons of the D–– phenotype has been reported to cause mild to fatal HDN. We report an example of anti-Rh17 produced by a black female with an e variant RBC phenotype that caused moderate HDN. A panel of seven monoclonal anti-e demonstrated her RBCs carried a variant e antigen, and her genotype was