Bimodal distribution of genomic MLL breakpoints in infant acute lymphoblastic leukemia

Background: A hallmark of infant leukemia is the high prevalence of chromosomal rearrangements involving the MLL gene. The most frequent partner genes are AF4, AF9, and ENL. Aim of this study was to assess breakpoint distribution within the MLL gene to evaluate association of recombination related sequence DNA motifs. Patients/Methods: The genomic fusion sites from 59 infant MLL samples (33 MLL-AF4, 10 MLL-AF9 and 16 MLL-ENL) were analyzed. Kernel density analysis and scan statistics were used to describe breakpoint distribution and clustering. Results: In contrast to previous studies based on smaller cohorts, b…