HUMAN TRITHORAX GENE REARRANGEMENTS IN THERAPY-RELATED ACUTE-LEUKEMIAAFTER ETOPOSIDE TREATMENT

Molecular analysis of leukaemic blasts from 9 patients with secondary myeloid leukaemia reveals rearrangements of the human trithorax gene ( Htrx-1) in three patients, including one in whom abnormalities of chro mosome 11 band q23 were not detected by conventional cytogenetics. All three patients had been treated with epipodophyllotoxins, whilst none of the six without rearrangements had received these agents. The pati ents with rearrangements also presented with different clinical featur es. These findings support the separation of secondary leukaemia into two classes, and correlate rearrangements of the Htrx-1 gene with a gr oup of secondary leukaemias that follow specific cancer treatment regi mens.