Five examples of a “new” blood group antibody, anti‐Rd (Radin), are reported. The corresponding antigen, Rd, is infrequent and does not correspond to any other known “low‐incidence” antigen. Family studies indicate that Rd is an autosomal dominant character which does not belong to the ABO, MNSs, Rh, Lutheran, Kell or Kidd blood group systems. Furthermore, the gene determining Rd is not closely linked to either the haptoglobin or red cell acid phosphatase loci. Anti‐Rd caused mild to moderate hemolytic disease of the newborn in all five families and has appeared with the first pregnancy.

Fanconi’s anemia is an inherited disorder characterized by multiple congenital abnormalities, chromosome anomalies and irreversible aplastic anemia. Patients, and possibly family members, have been noted to have an increased incidence of leukemia and other tumors. A family with two affected male children, one of whom developed acute myelomonocytic leukemia, is described. Chromosome preparations in both parents showed abnormalities, a previously unreported finding. Fibroblast cultures from both parents and one brother inoculated with Simian Virus 40, a known oncogenic agent, developed increased numbers of transformed colonies, compared with normal control cultures similarly inoculated. The presence of chromosome abnormalities and cellular susceptibility to oncogenic agents appear to be related to an increased risk of malignancy.