GATA1-related cytopenia is characterized by thrombocytopenia and/or anemia ranging from mild to severe. Thrombocytopenia typically presents in infancy as a bleeding disorder with easy bruising and mucosal bleeding (e.g., epistaxis). Anemia ranges from minimal (mild dyserythropoiesis) to severe (hydrops fetalis requiring in utero transfusion). At the extreme end of the clinical spectrum, severe hemorrhage and/or erythrocyte transfusion dependence are lifelong; at the milder end, anemia and the risk for bleeding may decrease spontaneously with age. One or more of the following may also be present: neutropenia, splenomegaly, cryptorchidism, hypospadias, and rarely additional clinical features of Diamond-Blackfan anemia. Heterozygous females may have mild-to-moderate symptoms such as menorrhagia. Rarely, GATA1-related cytopenia can progress to myelodysplastic syndrome or aplastic anemia. [from GeneReviews]