A rare case of GATA1 negative chemoresistant acute megakaryocytic leukemia in an 8-month-old infant with trisomy 21.

Children with Down syndrome (DS) have a unique form of acute megakaryocytic leukemia (AMKL) characterized by the presence of mutations in the GATA1 gene leading to increased chemosensitivity and a favorable outcome. We describe an 8-month-old male with DS who was diagnosed with AMKL without a mutation in the GATA1 gene. The patient was treated according to the DS-AML-regimen but his disease progressed and he succumbed 9 months later. This rare case of DS AMKL without a GATA1 mutation with an unfavorable outcome suggests that GATA1 testing may play a useful role in initial stratification.