Activating CBL mutations are associated with a distinct MDS/MPN phenotype

Ann Hematol. 2012 Nov;91(11):1713-20. doi: 10.1007/s00277-012-1521-3. Epub 2012 Aug 10.

Abstract

Activating point mutations in CBL have recently been identified in diverse subtypes of myeloid neoplasms. Because detailed clinical and hematological characteristics of CBL-mutated cases is lacking, we screened 156 BCR-ABL and JAK2 V617F negative patients with myeloproliferative neoplasms (MPN) and overlap syndromes between myelodysplastic syndrome (MDS) and MPN (MPS/MPN) for mutations in exons 8 and 9 of CBL by denaturing high-performance liquid chromatography and direct sequencing. CBL mutations were identified in 16/156 patients (10%), of which five also carried mutations in EZH2 (n = 3) and TET2 (n = 2). Comprehensive clinical and hematological characteristics were available from 13/16 patients (81%). In addition to splenomegaly (77%), striking common hematological features were CML-like left-shifted leukocytosis (85%) with monocytosis (85%), anemia (100%), and thrombocytopenia (62%). Thrombocytosis was not observed in any patient. Relevant bone marrow features (n = 12) included hypercellularity (92%) with marked granulopoiesis (92%), nonclustered microlobulated megakaryocytes (83%), and marrow fibrosis (83%). Nine deaths (progression to secondary acute myeloid leukemia/blast phase, n = 7; cytopenia complications, n = 2) were recorded. Three-year survival rate was 27%, possibly indicating poor prognosis of CBL mutated MDS/MPN patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cohort Studies
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Dioxygenases
  • Enhancer of Zeste Homolog 2 Protein
  • Exons
  • Female
  • Follow-Up Studies
  • Genetic Association Studies
  • Humans
  • Leukocytosis / etiology
  • Male
  • Middle Aged
  • Myelodysplastic-Myeloproliferative Diseases / diagnosis
  • Myelodysplastic-Myeloproliferative Diseases / genetics*
  • Myelodysplastic-Myeloproliferative Diseases / metabolism
  • Myelodysplastic-Myeloproliferative Diseases / physiopathology
  • Point Mutation*
  • Polycomb Repressive Complex 2 / genetics
  • Polycomb Repressive Complex 2 / metabolism
  • Prognosis
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-cbl / chemistry
  • Proto-Oncogene Proteins c-cbl / genetics*
  • Proto-Oncogene Proteins c-cbl / metabolism
  • Splenomegaly / etiology
  • Survival Analysis
  • Thrombocytopenia / etiology
  • Young Adult

Substances

  • DNA-Binding Proteins
  • Proto-Oncogene Proteins
  • Dioxygenases
  • TET2 protein, human
  • EZH2 protein, human
  • Enhancer of Zeste Homolog 2 Protein
  • Polycomb Repressive Complex 2
  • Proto-Oncogene Proteins c-cbl
  • CBL protein, human