[Chromosome 5q-- in the medullar cells of a patient with anaemia which later developed into acute non-differentiated leukaemia (author's transl)].

The authors report the observation of a 76-year-old man who since 1974 had a persistent anaemia considered as a pre-leukaemic state. The patient was hospitalized in May 1977 with fever and severe asthenia. The laboratory results indicated a probable diagnosis of acute non-differentiated leukaemia of stem cells. In spite of treatment, the anaemia grew worse, the leukocytosis accompanied by blast cells became more pronounced, a massive thrombopenia occurred and the patient died in irreversible shock. Cytogenetic examination done on a medullar culture revealed the presence in all the cells of a chromosome No. 5 with the long arms deleted : 46,XY,5q--. This rare medullar anomaly was reported for the first time in 1974-1975 by the Louvain school (Van den Berghe, Sokal, et al.) in a group of refractory anaemias. It has also been described in association with other chromosomal aberrations, in anaemias or other hemopathies which all developed into acute myeloblastic leukaemia. The clinical evolution and the cytogenetic data of the patient presented here are compared with those of other cases of 5q-- published in the literature, and the significance of this 5q-- chromosome aberration in hemopathies is discussed.