The fusions, TEL/AML1 and BCR/ABL, and rearrangements of the MLL gene occurred at frequencies of 22% (n = 447/2027) (25% in B-lineage ALL), 2% (n = 43/2027) and 2% (n = 47/2016) respectively.     ///    "The TEL/AML1 probe showed the highest incidence of variation (59%, n = 524/884), which included 38 (2%) patients with clustered, multiple copies of AML1. "