Myelofibrosis with complex chromosome abnormality in a patient with erythrocytosis due to hemoglobin rainier and treated with32P

Abstract
A patient with familial erythrocytosis associated with Hemoglobin Rainier, and previously treated with 32P, developed myelofibrosis with a hyperdiploid chromosome clone in the myeloid cells (51, XX, +1, 2q‐(q33), +6, +9, +11, ‐19, +20q +,+ mar 1). This transformation from a benign disorder of differentiated erythrocytes to a malignant disorder may have been secondary to radiophosphorus therapy.