Myeloproliferative disorder with unusual marrow chromosome constitution.

This report describes a patient referred at 14 years in 1971, after one year's surveillance by the family physician, for a persistently elevated erythrocyte sedimentation rate, leukopenia, and relative lymphocytosis. Despite the documented myeloproliferative syndrome of seven years, significant physiologic impairment precluding strenuous ranching and rodeo work appeared only in the last six to nine months. Throughout the clinical course characterized by pancytopenia, refractory and somewhat megaloblastic anemia partially responsive to oxymetholone, and subacute myeloblastic leukemia, he showed a persistent double trisomy--48, XY, +8, +21 in bone marrow. This report reiterates the value of chromosome analysis in the study of hematologic disorders and, in addition, emphasizes the need to individualize each patient's prognosis.