A New Red Cell Phenotype I-i: Red Cells Lacking Both I and i Antigens

Abstract
When blood samples from 5864 healthy Indian blood donors were tested with anti-I, 7 samples failed to react or reacted only weakly. Further studies with a number of anti-I and anti-i sera suggested that these samples had the phenotype I-i- and reacted weakly with anti-IT. In 1 family, the I-i- phenotype was present in 3 generations.