Recently I was asked to see a newborn infant, who manifested jaundice during the first twenty-four hours of life and whose mother was Rh-negative. This case presents several unusual features and is therefore reported.
In the first place, reference to the table shows that the mother belongs to type rh, while the father and all the children belong to type Rh1Rh2. Since the father belongs to type Rh1Rh2 and is hr' negative, he most likely belongs to genotype RzR1. The incidence of this genotype among Caucasoids is approximately 0.08 per cent.1 He could also belong to genotype Rzr', but the incidence of this genotype among Caucasoids is only about 0.001 per cent.1 Other, still rarer, possibilities are RZRZ, Rzrv and RlrV, the last of which is excluded by the occurrence of phenotype Rh1Rh2 (or R2) in the children.
Since the mother is Rh negative and the baby in question is