High frequency of the JAK2 V617F mutation in patients with thrombocytosis (platelet count>600x109/L) and ringed sideroblasts more than 15% considered as MDS/MPD, unclassifiable.

We wish to confirm recent reports showing that JAK2 V617F[1][1][⇓][2][⇓][3][⇓][4]–[5][5] is commonly detectable in patients with thrombocytosis who also have ringed sideroblasts in their bone marrow.[6][6][⇓][7][⇓][8]–[9][9] For such patients, the WHO classification provides the

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