Monosomy 7 in a patient with pancytopenia and abnormal erythropoiesis

In 1976, a patient with pancytopenia was found to have a population of marrow cells with monosomy of chromosome 7 (45, XY,–7). Over the next 3 years he had continued abnormal hematopoiesis consisting of erythroid hyperplasia, ring sideroblasts, megaloblastic changes, and an increased proportion of myeloblasts. Sequential chromosome studies consistently showed the same abnormality without further karyotypic change. From the present study and comparable cases in the literature, there appears to be a distinct subgroup of patients with myeloproliferative disorders showing dyserythropoiesis with monosomy or deletion of chromosome 7 in the marrow cells.