[Erythroid colonies derived from BFU-E from the bone marrow in a patient with type I congenital dyserythropoietic...

The findings of in vitro culture of bone-marrow BFU-E from a patient with type I dyserythropoietic anaemia are reported, scarce data being seemingly available in the literature. The number of BFU-E in the culture was increased four-fold with respect to the normal values. The morphologic study of the colonies showed in all cases varying number of erythroblasts with internuclear bridges (5-20%). Upon ultrastructural examination of the colonies, a great number of erythroblasts exhibited morphologic alterations, spongy chromatin and internuclear bridges being commonest. These findings suggest that an alteration of the progenitor erythroid cells exists in type I dyserythropoietic anaemia, whereas the morphological defects appreciated show great variation in the progeny of each BFU-E.