Complex variant 15;17 translocations in acute promyelocytic leukemia - A case report and review of three-way translocations

Complex variant 15;17 translocations are increasingly recognized in acute p romyelocytic leukemia (APL). We report a novel three-way translocation in A PL involving chromosomes 15, 17, and X in the form of t(X;17;15)(q13;q12;q2 1). Southern blot analysis showed retinoic acid receptor alpha (RARA) gene rearrangement at intron 2. Clinical and morphologic findings are typical of APL, and a complete remission was attained with a course of-conventional c hemotherapy. A review of three-way complex variants of 15;17 translocation in the literature reveals 21 published cases in addition to ours. PML/RARA fusion was observed in all 8 cases in which molecular genetic analysis had been performed. More cases need to be analyzed to determine if clustering t o particular chromosomal bands occurs in variant translocations, and whethe r APL cases harboring complex 15;17 variants differ clinically from those w ith classical 15;17 translocation. (C) Elsevier Science Inc., 1999. All rig hts reserved.