Simultaneous occurrence of MLL and RARA rearrangements in a pediatric acute lymphoblastic leukemia patient.

We report a case of concurrent translocations of MLL gene, associated with a highly distinct leukemia subtype and RARA gene, which is pathogenomic in acute promyelocytic leukemia. Conventional cytogenetic revealed a novel complex rearrangement between chromosomes 5, 11, and 17 resulting in a three-way chromosome translocation t(5;11;17)(q31;q23;q21). Fluorescence in situ hybridization analysis demonstrated that the 11q23 breakpoint involved the MLL, and the 17q21 breakpoint involved the RARA gene. Concurrent translocations of two specific oncogenes MLL and RARA with a new partner breakpoint on 5q31 have not been previously described.