Monosomy 7 in two patients with a myeloproliferative disorder.

Clinical and laboratory data are presented for two patients with a dyshaematopoietic disorder, and monosomy 7 in their bone marrow cells. The first patient, a 55-year-old woman, had been treated with chlorambucil for an ovarian carcinoma. After 4 years an oligoblastic myeloid leukaemia was diagnosed and she later died with an acute transformation of the disease. The second patient, a 21-year-old male, has had a dyserythropoietic anaemia with transient pancytopenia for over 5 years without any signs of malignancy. The possible relationship between therapy, the monosomy 7 and the other bone marrow abnormalities is briefly discussed. From an analysis of the data of these and comparable cases in the literature it appears that loss of chromosome No. 7 material is often associated with erythropoietic disorders such as erythroid hyperplasia and erythraemia. The reduction or absence of the Colton blood group antigens found in our patients and in a few other monosomy 7 cases also points to an abnormality of the red cell line.