Hematopoietic Cell Transplantation for Juvenile Myelomonocytic Leukemia

Juvenile myelomonocytic leukemia (JMML) is a rare myeloproliferative disorder of early childhood; it is characterized by hepatosplenomegaly and organ infiltration due to excessive proliferation of cells of the monocytic and granulocytic lineages. Approximately 85% of JMML patients harbor in their leukemia cells either somatic or germline mutations in the genes PTPN-11, NRAS, KRAS, NF1, or CBL. Allogeneic hematopoietic stem cell transplantation (HSCT) remains the therapy of choice for the majority of affected children. Available data indicate that transplantation from an HLA-identical sibling or a matched unrelated volunteer can cure more than 50% of patients. A similar proportion of children with JMML, especially when transplanted from donors with limited HLA disparity, can be cured with umbilical cord blood transplantation, which can represent a suitable option for children with JMML lacking either a related or an unrelated HSCT donor.