Unbalanced translocation t(5;17) in an atypical acute promyelocytic leukemia

✍ Scribed by Véronique Brunel; Danielle Sainty; Nadine Carbuccia; Christine Arnoulet; Régis Costello; Marie-Jöelle Mozziconacci; Jacqueline Simonetti; Lionel Coignet; Jean Gabert; Anne-Marie Stoppa; Françoise Birg; Marina Lafage-Pochitaloff

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 438 KB
• Volume: 14
• Category: Article
• ISSN: 1045-2257
• DOI: 10.1002/gcc.2870140410

✦ Synopsis

Abstract

Acute promyelocytic leukemia (APL; M3 in the FAB classification) is specifically associated with the t(15;17)(q23;q12) and the consequent formation of a PML/RARA fusion gene. A few cases of APL with a t(11;17)(q23;q12) and a PLZF/RARA fusion gene have recently been reported. In addition, a new variant, t(5;17)(q32;q12), with a RARA rearrangement was described in a child with atypical APL. We report an unbalanced der(5)t(5;17) in an atypical APL case showing unusual dysgranulopoiesis and some M2 features. The breakpoints were difficult to localize precisely on chromosome 5, because the translocation may have occurred on a previous del(5q). The karyotype also showed del(8q) and multiple double‐minutes (dmin). Molecular studies evidenced RARA rearrangement but showed neither PML rearrangement nor PML/RARA fusion. Fluorescence in situ hybridization revealed that the dmin were of chromosome 8 origin and that they accounted for the MYC amplification observed in Southern blots. The patient did very poorly despite chemotherapy and all‐trans retinoic acid (ATRA) treatment. Thus, the t(5;17) could represent a second type of variant translocation in APL that, like the disease associated with t(11;17), does not seem to respond to ATRA therapy. Whereas RARA rearrangement appears sufficient for an APL‐like phenotype, it seems that the presence of a classical PML/RARA is required for typical APL with response to ATRA.