Secondary chromosomal abnormalities in acute lymphoblastic leukemia

Secondary chromosomal abnormalities (both numerical and structural) were studied in 55 Acute Lymphoblastic Leukaemia (ALL) patients of Orissa (India) of which only 44 patients could provide good chromosome spreads. In addition to the primary aberrations, these patients exhibited various kinds of secondary aberrations like hyperdiploids, pseudodiploids, aneuploids, stickiness, pulverisation, chromatin extraction, chromatid gap, chromatin constriction, isochromatid breaks, endomitoses, ring chromosomes etc. These aberrations appeared either singly or in various combinations. A majority (40 out of 44) of studied patients possessed secondary aberrations. The frequencies of secondary aberrations were found to increase with the progression of the disease and patients with highest number of such aberrations had the worst chance of survival. The probable causes and the prognostic implications of these aberrations are discussed.