RPS19 and Erythroid hypoplasia: Although the exact mechanism of DBA has not been fully elucidated, there is evidence that the defective erythropoiesis may be associated with a blockage between the consecutive erythroid burst-forming unit- and the colony-forming unit stages of erythroid development.[4] A ribosomal processing defect in patients with DBA causes this blockade resulting in erythroblastopenia or paucity of the erythropoietic cell line on the bone marrow microscopy.