Identification of two new translocations that disrupt the AML1 gene

The AML1 gene, located at chromosome 21q22, encodes a component (CBFα2) of a heterodimeric transcription factor complex termed core binding factor (CBF), which binds to DNA and activates gene expression. Chromosomal rearrangements may lead to disruption of this gene and development of acute leukemia. Twelve AML1 translocations have been identified to date, and include sites on chromosomes 1, 2, 3, 5, 8, 12, 14, 15, 16, 17, 18, and 19. Here we report two new translocations involving AML1 in acute myeloid leukemia, in which the disruption of the AML1 gene was documented by GTG banding cytogenetic studies and metaphase and interphase FISH analysis. These chromosomal breakpoints identified as harboring new fusion partners for AML1 are at 2p11.2 and 20q13.1. The two patients in who these translocation were identified were elderly males with newly diagnosed AML. These patients shared the same poor outcomes reported for other rare AML1 translocations.