Inv(1)(p22q25) in chronic myeloproliferative disease: constitutional or clonal defect?

Pericentric inversion of chromosome 1 is uncommon in chronic myeloproliferative disease. We report the occurrence of an isolated inv(1)(p22q25) in two patients with BCR/ABL-negative chronic myeloproliferative disease. The inv(1) is an acquired clonal abnormality in one patient and a constitutional defect in the other. To our knowledge, this is the first report on the occurrence of inv(1)(p22q25) in hematolymphoid malignancies.