TRANSIENT LEUKEMIA FOLLOWED BY MEGAKARYOBLASTIC LEUKEMIA IN A CHILD WITH MOSAIC DOWN-SYNDROME

A case is presented of a child with mosaic Down syndrome, who presente d at birth with a transient leukemia and later progressed to megakaryo blastic leukemia. Evidence is presented that both leukemias were of me gakaryoblastic lineage and evolved from a trisomic hematopoietic precu rsor. This case is unique in the poor course of the initial transient neonatal leukemia with improvement following chemotherapy. It also hig hlights the form of leukemia and associated myelodysplasia that occurs in children with Down syndrome. This form of leukemia and transient l eukemia are interrelated and are unique to children with Down syndrome .