RESUMO
Severe congenital neutropenia [SCN], Kostmann syndrome is a heterogenous disorder of myelopoiesis characterized by severe chronic neutropenia, absolute neutrophil count [ANC] persistently below 0.50 x 109/L, with maturation airest of neutrophil precursors in the bone marrow; and associated with serious recurrent b eteriiinfections from early infancy. Sepsis mortality is reduced by an advent of granulocyte colony stimulating factor [G-CSF] therapy. More than 90% of patients respond to G-CSF therapy. However, hematopoietic stem cell transplantation has shown promise in the treatment of non-responders. About 60-80% of SCN cases are associated with constitutive mutations in one copy of the gene encoding neutrophil elastase ELA2. Myelodysplastic syndrome and acute myeloid leukemia [MDS/AML] have been reported. The hazard of MDS/AML increases significantly overtime. Approximately 10% of patients with severe congenital neutropenia develop AML. This is not thought to be the direct result of G-CSF therapy but related to the underlying disease itself