Genetic alterations in patients with chronic leucocytosis and persistent thrombocytosis.

To elucidate the relevance of genetic alterations, we analysed 17 genes known to be involved in haematological neoplasms in patients with chronic leucocytosis and patients with persistent thrombocytosis. Mutations of the , and genes were found in 1/13, 1/13, and 2/13 patients with leucocytosis, respectively. Mutations of the , , and genes were found in 1/5, 1/5, 1/5 and 2/5 patients with thrombocytosis, respectively. One leucocytosis patient with a V617F mutation developed polycythaemia vera. Another leucocytosis patient developed Philadelphia chromosome-negative chronic myeloid leukaemia (Ph(-) CML) accompanied by t(9;12)(q34.1;p13.?3) (Mori . 2016). Another leucocytosis patient with mutations of the and genes progressed to blast crisis of Ph(-) CML accompanied by i(17)(q10). Chronic leucocytosis patients who had genetic alterations tended to develop haematological neoplasms, while thrombocytosis unexpectedly resolved in two persistent thrombocytosis patients with genetic alterations.