Two kindred with the rare dominant inhibitor of the lutheran and p1 red cell antigens.

Two kindred each showing the dominant inheritance of the rare phenotype lu(a-b-) in the Lutheran blood group system are recorded. The pedigrees illustrate the expected upset in the occurrence of the P1 antigen in the Lu(a-b-) members. A third Lu(a-b-) propositus of the dominant type was found after testing a further 3,197 donors on the East Anglian panel. The phenotype Lu(a-b-) may not be quite as rare as previously supposed.