Erythrocyte membrane proteins in an unusual case of congenital dyserythropoietic anaemia type II (CDA II).

Analysis of the erythrocyte membrane protein of an atypical case of congenital dyserythropoietic anaemia type II (CDA II) by electrophoresis on polyacrylamide gels revealed marked abnormalities. One-dimensional analysis showed a pronounced decrease in levels of B1.1 components, an increase in the level of B1.4 and the appearance of new components in the A region as well as in the C region of the gel. There were no artefacts due either to the presence of early red cells or to abnormally high levels of proteolytic enzyme activity in the CDA II preparations. Two-dimensional analysis confirmed the alterations in membrane components showing two novel A region species not reported in other studies of this disease. Abnormalities in components of such large molecular size may explain the greater degree of membrane perturbation seen in the present case and support the idea that CDA II may embrace more than one disease entity.