Congenital dyserythropoietic anaemia type II (CDA-II): chromosomal banding studies and adherent cell effects on erythroid colony (CFU-E) and burst (BFU-E) formation.

Bone marrow CFU-E and BFU-E from a patient with CDA-II formed erythroid colonies and bursts which contained multinucleated erythroblasts in vitro. Adherent cell depletion of the patient's marrow increased CFU-E derived colonies six-fold (98 +/- 17 v. 640 +/- 15 per 10(5) marrow cells plated) and co-culture of CDA-II marrow adherent cells with CSA-II adherent cell depleted marrow significantly suppressed erythroid colony formation. Similar adherent cell suppression of the patient's BFU-E also occurred. Adherent cell depletion of normal marrow did not increase CFU-E derived colony formation (488 +/- 63 v. 495 +/- 108) and decreased BFU-E derived burst formation. Addition of normal adherent cells to normal marrow increased erythroid colony and burst formation. Karyotype and chromosomal banding studies of the patient's multinucleated cells did not show chromosomal inversions, deletions or translocations.