Cytogenetics in autologous bone marrow transplantation

C.F., a boy born in 1985, was diagnosed as having T-cell ALL of the L1 type (French-American-British (FAB) classification) in May 1987, when a chromosome analysis of bone marrow showed a translocation between the chromosomes 3 and 5 as the sole acquired anomaly. The karyotype was 46,XY,t(3; 5)(q25; q22)/46,XY (Table 1). In January 1988, the morphological picture of a marrow biopsy indicated complete remission, and bone marrow cells were harvested for ABMT. A chromosomal analysis of this material showed one cell with the translocation (3; 5) among the 36 cells examined. As a consequence ABMT was not performed and a severe relapse of the disease occurred in the following months, with evident proliferation of the clone with the t(3; 5).