SPECIFIC CHROMOSOMAL-ABERRATIONS IN POLYCYTHEMIA-VERA

Abstract

The chromosomes of bone marrow cells from 10 patients with polycythemia vera (PV) were identified by Q-, G-, C- banding techniques. Four of the patients had received no treatment with cytotoxic drugs, while 3 had received 32P only and the other 3, in addition, had received busulfan or busulfan and procarbazine. One 73 yr old male patient treated with venesection only for 4 yr lacked the Y chromosome and had a deletion of the long arm of chromosome 20 (20q-) in all cells investigated. One of the other 3 patients who had received no drugs had a chromosome abnormality, but only in 1 of 19 identifiable metaphases. The abnormality was the same (+9) as the most common one in treated patients. In the group of treated patients, an extra chromosome 9(+9) was found in 3 patients, an extra chromosome 8 (+8) in 1, and a deletion of the long arm of 1 chromosome 20 (20q-) in 1 patient. Multiple aberrations in addition to the extra chromosome 9 were found in 1 patient in whom the disease had transformed into acute myeloblastic leukemia. The finding of identical chromosomal aberrations (20q- and +9, respectively) in 2 patients who had received no drugs and in 4 patients who had received 32P and busulfan or procarbazine favored the view that these aberrations were specifically associated with the disease and not induced by the drugs. With the exception of the patient with acute myeloblastic leukemia, all other patients are alive 1-11 mo. after chromosome analyses and 1-229 mo. after diagnosis.