- Congenital dyserythropoietic anemia (CDA) type I is an inherited disorder characterized by macrocytic anemia with pathognomonic morphologic ultrastructural features of the erythroid precursors. The authors recently cloned the CDAN1 gene and identified one founder missense mutation in all of their Bedouin patients. In a previous study, the authors found that the majority of their 31 Bedouin patients had anemia and jaundice during the first month of life and required blood transfusions; some had persistent pulmonary hypertension. In the present retrospective evaluation of 70 Bedouin patients with CDA type I, the authors more than doubled the number. Forty-five (64%) patients were symptomatic in the neonatal period, 29 (65%) had hepatomegaly, 24 (53%) had early jaundice, 11 (27%) were born small for gestational age, 7 (15%) had persistent pulmonary hypertension, and 6 (13%) had direct hyperbilirubinemia and another 6 (13%) had transient thrombocytopenia. Thirty-six of the symptomatic neonates (80%) required at least one blood transfusion. These results confirm the authors' previous findings and add neonatal manifestations not previously described, particularly hyperbilirubinemia and thrombocytopenia. Early diagnosis of CDA type I may be beneficial in light of the potential efficacy of alpha-interferon in avoiding transfusions in some patients.