Phenotypic characteristics of patients affected by classical DBA, DBA-like conditions (erythroblastopenia unrelated to an RP gene mutation), and GATA1 DBA-related conditions. Summary of the phenotypic characteristics of DBA-affected patients who fit the DBA definition of congenital erythroblastopenia, with an allelic variation in a ribosomal gene leading to a defect in ribosomal biogenesis and in particular to a defect in rRNA maturation; DBA-like patients who exhibit a congenital erythroblastopenia with some response to steroid but exhibit no defects in ribosomal biogenesis or rRNA maturation (genes ascribed to this phenotype to date are EPO and ADA2); and DBA-like patients who carry a mutation in the GATA1 gene and exhibit some dyserythropoiesis/dysmegakaryopoiesis features in their hypocellular bone marrow. MCV, mean corpuscular volume.