Rearrangement of the MLL Gene in Acute Lymphoblastic and Acute Myeloid Leukemias with 11q23 Chromosomal Translocations

The molecular analysis of recurring structural abnormalities of chromosomes in human neoplasia has led to the identification of a number of genes involved in these rearrangements. Alterations in these genes are implicated in the development of malignant conditions. For example, in chronic myelogenous leukemia, the proto-oncogene ABL is translocated from chromosome 9 to the BCR gene on chromosome 22, leading to the generation of a chimeric gene and a fusion protein 1 . In lymphoid cancers, translocations frequently involve the immunoglobulin or T-cell-receptor genes, which are juxtaposed to critical oncogenes, causing their abnormal expression 2 . Recently, many of the chromosomal translocation . . .