THE RH-NULL PHENOTYPE IN AN ENGLISH INDIVIDUAL - HEMATOLOGICAL, SEROLOGICAL AND IMMUNOLOGICAL STUDIES

We have characterized the first case of Rh-null phenotype to be identi fied in England, The red cells were serologically negative for C, c, C -W, D, E, e, f, hr(B), Rh17, Lw(a), LWab and Duclos, while the patient 's serum contained anti-Rh29, which was subsequently boosted by transf usion, The Rh phenotype of the patient's son (R(1)r) confirmed that th is was a regulator type of Rh-null in the patient. Follow up studies c onfirmed the presence of a mild chronic anaemia with stomatocytes and spherocytes; electron microscopy revealed the presence of cells with d eep central indentations. Osmotic fragility was increased to a Level i ntermediate between normal and hereditary spherocytic controls. The pr esence of ongoing haemolysis was indicated by a mild reticulocytosis a nd splenomegaly. The potent anti-Rh29 has made the provision of compat ible brood difficult and autologous units have been frozen. The case i llustrates the rare phenomenon of the Rh-null phenotype which not only causes problems for the transfusionist but should also be recognized as a cause of haemolytic anaemia secondary to a membrane defect. Blood film and Rh phenotyping are useful preliminary investigations in susp ected cases.