Chromosome aberrations and prognosis in preleukaemia.

24 patients with preleukaemia were cytogenetically studied by the G-banding staining technique. All patients developed later frank acute non-lymphocytic leukaemia and died. 13 patients had a completely normal karyotype (NN-patients) with a median survival time of 8 months. 6 patients had both normal and abnormal metaphases (AN-patients) with a median survival time of 18.5 months, while 5 patients had abnormal metaphases only (AA-patients) with a median survival time of 3 months.