Chromosomal abnormality, megaloblastosis, and arrested DNA synthesis in erythroleukaemia.

Abstract

Chromosomal studies of bone-marrow cells have been reported on 30 patients with erythroleukaemia (Table Some of these reports give only meagre cytogenetic details, but there was an increased degree of polyploidy in at least 9 of the patients, sig- nificant aneuploidy in 12, and structural abnor- malities in 11. Some patients showed more than one of these features, and only 8 patients had normal chromosomes. For several reasons these reports probably do not give a reliable estimate of the incidence of cytogenetic abnormality in erythroleu- kaemia, but they do indicate that structural changes, which are often associated with hypodiploid num- bers, and polyploidy are prominent features of this leukaemia. The structural abnormalities included separate instances of chromosome breakage in different cells of untreated patients (Heath and Moloney, 1965; Weatherall and Walker, 1965; Jensen, 1966), and also the presence ofcytogenetically abnormal cell lines, the most notable being the ring chromosomes described in two patients