Alterations of globin chain synthesis and of red cell membrane proteins in congenital dyserythropoietic anemia I and II.

Red cell membrane proteins were investigated in two unrelated children with congenital dyserythropoietic anemia (CDA) I and two siblings with CDA II. The CDA I patients displayed globin chain synthesis imbalance, with reduction of the non alpha/alpha ratio. One of the CDA II patients presented the reverse alteration. Whenever globin chain synthesis was unbalanced, the membrane p-nitrophenylphosphatase had an abnormally biphasic kinetics, consistent with substrate excess inhibition, as is observed in alpha- or beta-thalassemic syndromes. One CDA I patient displayed a decrease of electrophoretic band 4.1 along with an ectopic phosphorylated protein at the level of band 4.2. In CDA II and, to a lesser extent, in CDA I, the in vitro endogenous phosphorylation of band 2 + 2.1 was sharply reduced.