[Study of caryotype in pre-leukaemic states (author's transl)].

Twenty-four patients, in a condition considered to be pre-leukaemic underwent study of marrow caryotype. Nine of them (37.5%) had an abnormal caryotype. The prevalence of abnormalities varied according to the type of pre-leukaemic state: 17% in acquired idiopathic sideroblastic anaemia, 33% in refractory anaemias with excessive myeloblasts, 100% in 3 cases of simple refractory anaemia. The abnormalities were non-systematised. However, in one case there was an abnormality already described in the literature and considered to be specific: deletion of the long branch of chromosome 5. In refractory anaemias with excess myeloblasts transformation to acute leukaemia appeared to be more frequent in patients with an abnormality (4/5) than in patients with a normal caryotype (0/10).