Lab Med Online.  2011 Oct;1(4):232-236. 10.3343/lmo.2011.1.4.10.

A Case of Atypical Chronic Myeloid Leukemia with the JAK2V617F Mutation

  • 1Department of Laboratory Medicine, Korea University College of Medicine, Seoul, Korea.
  • 2Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.


Atypical chronic myeloid leukemia (aCML) is a rare leukemic disorder that shows myelodysplastic and myeloproliferative features simultaneously. The Janus kinase 2 gene V617F mutation (JAK2V617F) in aCML has been the source of much controversy. Some JAK2V617F positive cases have been reported but others observed no JAK2V617F mutation in aCML as defined by WHO classification. Recently, we experienced a case of aCML with JAK2V617F mutation with typical myelodysplastic/myeloproliferative features in peripheral blood and bone marrow aspirates. The karyotype was normal and no BCR/ABL1, PDGFRA or PDGFRB gene rearrangement was noted with FISH analysis. JAK2V617F mutation of the case was identified with amplification refractory mutation system PCR and direct sequencing. We also studied JAK2V617F mutation status in 3 additional cases of previously diagnosed aCML in our institution, but no mutation was identified.


Atypical chronic myeloid leukemia; JAK2; Myeloproliferative disorder; Myelodysplastic syndrome; BCR-ABL1

MeSH Terms

Bone Marrow
Gene Rearrangement
Janus Kinase 2
Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative
Myelodysplastic Syndromes
Myeloproliferative Disorders
Polymerase Chain Reaction
Receptor, Platelet-Derived Growth Factor beta
Janus Kinase 2
Receptor, Platelet-Derived Growth Factor beta


  • Fig. 1 Pictures of peripheral blood smear and bone marrow aspirate smear. (A) Peripheral blood smear illustrates dysplastic neutrophils with hypogranulation and hyposegmentation (Wright stain, ×1,000). (B) Bone marrow aspirate smear shows left-shifted maturation and dysgranulopoiesis such as megaloblastic change and hypogranulation (Wright stain, ×1,000). (C) Bone marrow biopsy shows hypercellularity due to granulocytic proliferation (H&E stain, ×200).

  • Fig. 2 Results of JAK2V617F gene mutation analyses. (A) Amplification refractory mutation system PCR (ARMS-PCR) analysis. The size of the products is indicated on the right. Aberrant band was detected in the patient lane. PC, positive control; NC, negative control, (B) Direct sequencing analysis. The heterozygous c.1849G>T (p.V617F) mutation was noted.


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