Clonal analysis of NRAS activating mutations in KIT-D816V systemic mastocytosis.
Cooperating genetic events are likely to contribute to the phenotypic diversity of KIT-D816V systemic mastocytosis. In this study, 44 patients with KIT-D816V systemic mastocytosis were evaluated for coexisting NRAS, KRAS, HRAS or MRAS mutations. Activating NRAS mutations were identified in 2 of 8 patients with advanced disease. NRAS mutations were not found in patients with indolent systemic mastocytosis. To better understand the clonal evolution of mastocytosis, we evaluated the cell compartments impacted by the NRAS and KIT mutations. Clonal mast cells harbored both mutations. KIT-D816V was not detected in bone marrow CD34(+) progenitors, whereas the NRAS mutation was present. These findings suggest that NRAS mutations may have the potential to precede KIT-D816V in clonal development. Unlike other mature lineages, mast cell survival is dependent on KIT and the presence of these two activating mutations may have a greater impact on the expansion of this cell compartment and in resultant disease severity.
Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, 20892-1881, USA. twilson@niaid.nih.gov
Todd M
TM
Wilson
Irina
I
Maric
Olga
O
Simakova
Yun
Y
Bai
Eunice Ching
EC
Chan
Nicolas
N
Olivares
Melody
M
Carter
Dragan
D
Maric
Jamie
J
Robyn
Dean D
DD
Metcalfe
D000368:Aged; D000906:Antibodies / Q000276:immunology / Q000378:metabolism; D018952:Antigens, CD34 / Q000235:genetics / Q000276:immunology; D001853:Bone Marrow / Q000378:metabolism / Q000473:pathology; D002999:Clone Cells / Q000378:metabolism / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D034721:Mastocytosis, Systemic / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics* / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*
D000906:Antibodies; D018952:Antigens, CD34; D019009:Proto-Oncogene Proteins c-kit; D016283:Proto-Oncogene Proteins p21(ras)