Hereditary thrombophilia and myeloproliferative disorders (MPD) are risk factors of VTE. The JAK2 V617F mutation may be found in polycythemia vera (PV), essential thrombocythemia (ET) and myelofibrosis. We report three women referred to our out-patient clinic for a thrombophilia screening. JAK2 mutation was studied using wild type FRET probes and subsequent analysis of the melting curve (

James et al,
Leukemia
2006
;
20
:
350
–353
). Patient 1, 75 year-old (yo), had pulmonary embolism (PE) and proximal deep vein thrombosis (DVT) at 68. We detected heterozygous FV Leiden (FVL) and FII 20210A mutations. In 2005, she had internal jugular vein thrombosis after surgery (platelet count > 600 G/L). ET was suspected in 2006. Patient 2, 44 yo, on oral contraception, had PE and proximal DVT at 33 after sclerotherapy, recurrent massive PE requiring emergency embolectomy and proximal DVT during pregnancy. Heterozygous FVL was detected in 1995 (platelet count was 432 G/L) and ET in 2000. Patient 3, 65 yo, with PV detected in 1995, had a proximal DVT one year later. Heterozygous FVL was detected. She is the only patient treated with hydroxyurea. Results of blood cell counts and JAK2 V617F/JAK2 WT ratios are shown in the table. Conclusion 1. JAK2 mutation was found in 3 patients with VTE, platelet count >400 G/L and hereditary thrombophilia; 2. the risk of VTE related to JAK2 needs further investigation; 3. JAK2 V617F increased over time in 2 of 3 cases; 4. its early detection might improve the diagnosis and treatment of MPD and VTE.

PatientYearPlatelet (G/L)Hemoglobin (g/dl)Hematocrit (%)Leukocytes (G/L)JAK2 ratio
1 2000 431 15.3 45.9 8.6 10% 
     2006 448 13.9 43.3 10.4 50% 
2 1997 541 14.1 42.6 6.1 25% 
 2005 796 14.0 42.8 7.4 15% 
3 1997 501 14.1 42.6 4.6 15% 
 2003 609 13.6 42.1 5.8 20% 
 2006 485 12.8 37.9 4.8 50% 
PatientYearPlatelet (G/L)Hemoglobin (g/dl)Hematocrit (%)Leukocytes (G/L)JAK2 ratio
1 2000 431 15.3 45.9 8.6 10% 
     2006 448 13.9 43.3 10.4 50% 
2 1997 541 14.1 42.6 6.1 25% 
 2005 796 14.0 42.8 7.4 15% 
3 1997 501 14.1 42.6 4.6 15% 
 2003 609 13.6 42.1 5.8 20% 
 2006 485 12.8 37.9 4.8 50% 
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Topics:
jak2 gene v617f, oral contraceptives, time factors, venous thromboembolism, deep venous thrombosis, proximal, hereditary thrombophilia, deep vein thrombosis, early diagnosis, embolectomy, factor v leiden

Disclosure: No relevant conflicts of interest to declare.

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2006, The American Society of Hematology
2006
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