Partial deletion of long arm of chromosome 17: a specific abnormality in acute promyelocytic leukemia?

Two patients with acute promyelocytic leukemia had an identical chromosomal abnormality detected by fluoresecence banding. In each case, the clinical course was rapidly fatal, and was characterized by a lack of response to chemotherapy with cytarabine and thioguanine, and was complicated by disseminated intravascular coagulation. Bone marrow cells from each patient contained 46 chromosomes; in each instance, however, one chromosome 17 had a deletion of almost one half of the proximal portion of the long arm [del(17)(q11q21 or 22)].