We report the case of a female newborn with severe congenital anemia presenting as hydrops fetalis, followed by a clinical picture of transfusion-dependent hypoproliferative anemia. The most common causes of hydrops fetalis due to a severe non-immune hemolytic anemia are homozygous alpha-thalassemia, pyruvate kinase deficiency and other non-spherocytic anemias, autosomal recessive (AR) hereditary spherocytosis (HS), hereditary xerocytosis and congenital dyserythropoietic anemia (CDA).
Congenital hemolytic anemia with reticulocytopenia and dysplasia of erythroid precursors is rare and CDA should be included in the differential diagnosis. The diagnostic process in our patient was complicated by inconclusive laboratory testing due to her transfusion dependency and her final diagnosis was only established after the introduction of whole exome sequencing (WES).