A second Dr(a-) proposita with anti-Dra and a family with the Dr(a-) phenotype in two generations.

An Israeli Jewish woman who originated from the Uzbekskaya SSR in the south of the Soviet Union, had anti-Dra in her serum and her red cells were Dr(a-) as were those of three of her four children. All Dr(a-) red cells had weakened expression of their Cra, Tca, Esa, IFC, and other Cromer-related antigens. It is suggested that the Dr(a-) phenotype may result from inheritance of a dominant inhibitor gene, although a relatively common recessive allele of Dra was not excluded. Anti-Dra was inhibited by serums from the Dr(a+), but not the Dr(a-), members of the family.