+8. BCR/ABL t(9;22), 13q-, 20q-
Myeloproliferative disorder (MPD)
Fluorescence in situ Hybridization (FISH)
2.0 mL (min. 1.0 mL) peripheral blood in sodium heparin preferred, EDTA accepted
1.0 mL (min. 0.5 mL) bone marrow in sodium heparin preferred, EDTA accepted
Whole blood and bone marrow, ship ambient
Clotted specimen; Specimens exposed to extreme temperature; Anticoagulant toxic to cells; Insufficient number of cells
A group of pre-leukemic diseases, myeloproliferative disorders are characterized by a clonal expansion of one or more lineages of the myelo-erythroid series of which polycythaemia vera, essential thrombocythaemia and idiopathic myelofibrosis are the main malignant diseases formed. 30-40% of patients with polycythaemia vera and idiopathic myelofibrosis have chromosomal abnormalities and these indicate a poor prognosis, while patients with essential thrombocythaemia rarely have chromosomal abnormalities. Acquired changes seen at diagnosis include del(20q), del(13q), trisomy 8 and 9 and duplication of segments of 1q.
The V617F mutation in the JAK2 gene has also been found in ~97% of patients with polycythemia vera, ~57% of patients with essential thrombocythemia and ~50% of patients with myelofibrosis. JAK2 is offered as a reflex test in “Philadelphia negative” (t[9;22]) chronic myeloproliferative disorders.