Analysis of bcr rearrangements in primary (essential) thrombocythaemia.

A clinical and molecular study was performed on 10 patients with the presumptive diagnosis of primary thrombocythaemia (PTH). In all cases conspicuous megakaryocytic proliferation in bone marrow smears was detected in the absence of the Philadelphia chromosome (Ph1), elevated red blood cell mass and evidence for a reactive cause of the thrombocytosis. We analyzed whether rearrangements of the bcr gene occurred in untreated patients. Bcr rearrangements were detected in the bone marrow cells but not in peripheral blood bells of one patient, indicating that this case might be related at the molecular level with Philadelphia chromosome negative CML, in which bcr rearrangements could be demonstrated.