Detection of c-kit point mutation Asp-816 → Val in microdissected pooled single mast cells and leukemic cells in a patient with systemic mastocytosis and concomitant chronic myelomonocytic leukemia

Abstract 

The c-kit mutation Asp-816→Val is detectable not only in neoplastic mast cells (MCs) in patients with systemic mastocytosis (SM) but also in most associated hematologic non-MC lineage disease (AHNMD). In order to prove a monoclonal disease evolution we investigated DNA of pooled microdissected single cells for the presence of the mutation in a patient with SM and concomitant chronic myelomonocytic leukemia (CMML). LightCycler melting curve analysis and direct sequencing of nested polymerase chain reaction (PCR) products revealed the c-kit mutation in tryptase-positive MC and in leukemic CD15-positive cells in bone marrow infiltrates, but not in colonic epithelial cells, thus, suggesting a monoclonal evolution of SM and concurrent CMML on the basis of a somatic mutation in a common hematologic progenitor.

Abbreviations:  AHNMD, associated hematologic non-MC lineage disease, AML, acute myeloid leukemia, ASM, aggressive systemic mastocytosis, Asp, asparagine, BM, bone marrow, CMML, chronic myelomonocytic leukemia, EDTA, ethylenediaminetetra-acetic acid, ISM, insolent systemic mastocytosis, MC, mast cell, MCL, mast cell leukemia, MDS, myelodysplastic syndrome, MPS, myeloproliferative syndrome, PCR, polymerase chain reaction, SCF, stem cell factor, SM, systemic mastocytosis, U, unit, UP, urticaria pigmentosa, Val, valine

Keywords:  Mast cells, Microdissection, c-kit, Point mutation, Tryptase