[Myeloproliferative disorders and leukemia related to Down syndrome. Report of two clinical cases in neonatal period].

Down syndrome predisposes to haematological disorders. It is estimated that 5-30% of neonates with this condition will develop transient abnormal myelopoiesis. Treatment is not standardized; exchange transfusion and the use of cytarabine could be effective. We present two clinical cases of patients with Down syndrome, who during the neonatal period showed acute myeloid leukemia and transient abnormal myelopoiesis, the treatments used and their outcomes. Suspicion and early diagnosis of this entity are considered determining factors in prognosis.