A Japanese Rhmod family: serological and haematological observations.

This report describes a Japanese family have two Rhmod members, and two sibs with slightly depressed Rh antigens. It is proposed that the Rhmod and the depressed Rh antigen phenotypes are due to regulator genes in homozygous or heterozygous condition, respectively. The two Rhmod members showed mild reticulocytosis, stomatocytosis, slight anisocytosis, slight hyperchromia and slight punctate basophilia without anaemia. Scanning electron microscopy showed their red cells to be small and of bowl shape. Increased fragility of their erythrocytes was demonstrated by dynamic osmofragility testing using a coil planet centrifuge.