JAK2 V617F mutation in myelodysplastic syndrome, myelodysplastic syndrome/myeloproliferative neoplasm, unclassifiable, refractory anemia with ring sideroblasts with thrombocytosis, and acute myeloid leukemia.
BACKGROUND
The JAK2 V617F mutation has been noted in the cases of polycythemia vera, essential thrombocythemia, and primary myelofibrosis patients. This mutation occurs less frequently in acute myeloid leukemia (AML) and other hematologic diseases, such as myelodysplastic syndrome (MDS); myelodysplatic syndrome/myeloproliferative neoplasm, unclassifiable (MDS/MPN-U); and refractory anemia with ring sideroblasts with thrombocytosis (RARS-T).


METHODS
Patients diagnosed with hematologic diseases other than MPN who visited Seoul St Mary's Hospital from January 2007 to February 2010 were selected. A total of 43 patients were enrolled in this study: 12 MDS, 9 MDS/MPN-U, 7 RARS-T, and 15 AML patients. The diseases were diagnosed according to the 2008 WHO classification criteria. Data obtained from JAK2 V617F mutation analysis and cytogenetic study as well as complete blood count and clinical data were analyzed.


RESULTS
Of the 43 patients, 6 (13.9%) harbored the JAK2 V617F mutation. The incidence of the JAK2 V617F mutation in each patient group was as follows: 8.3% (1/12), MDS; 22.2% (2/9), MDS/MPN-U; 14.3% (1/7), RARS-T; and 13.3%, (2/15) AML. The platelet count was higher than 450×10(9)/L in 3 of the 6 patients (50%) harboring the JAK2 V617F mutation, and it was in the normal range in the remaining 3 patients. Among the 6 patients, 1 MDS and 1 MDS/MPN-U patients had the 46,XX,del(20)(q11.2) karyotype.


CONCLUSIONS
The JAK2 V617F mutation is associated with an increased platelet count in MDS, MDS/MPN-U, RARS-T, and AML patients. Cytogenetic abnormalities of del(20)(q11.2) occurred in 1/3 of patients with the JAK2 V617F mutation but further studies are required to confirm this association.
Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Dong Wook
DW
Jekarl
Sang Bong
SB
Han
Myungshin
M
Kim
Jihyang
J
Lim
Eun-Jee
EJ
Oh
Yonggoo
Y
Kim
Hee-Je
HJ
Kim
Woo-Sung
WS
Min
Kyungja
K
Han