BACKGROUND: Chromosomal rearrangements in addition to t(15;17) have been reported in 25-40% of
APL patients, with a large predominance of trisomy 8. Other abnormalities are far less frequent, particularly as ider(17), and the prognostic significance is still unclear.
METHODS: We present the
case of a patient with t(15;17)(q22;q21), der(15)t(15;17) and ider(17)(q10)t(15;17)(q22;q21). In particular, the RT-PCR result for PML-RARA of this patient was a false negative and mutational analysis of AML-related genes showed SNP rs2454206 in the TET2 gene and yielded negative findings in other genes including AML1, ASXL1, CEBPA, DNMT3A, FLT3, KIT, NPM1, TP53, and U2AF1. After the early usage of arsenic trioxide combinated with ATRA and vigorous supportive treatment to maintain PLT ≥30×109/L and FIB >1500 mg/L, this patient was under MMR and HCR without any clinical symptoms or signs until now.
CONCLUSIONS: False negative reslults of RT-PCR analysis for PML-RARA are rare in
APL and ider(17) is even more infrequent. To our knowledge, this is the first reported
case of
APL with ider(17) and false negative RT-PCR analysis results. The role of ider(17) in
APL is still an ongoing investigation and limited by the small number of published cases. The patient reported here benefited from vigorous supportive treatment during the combination of ATRA and arsenic trioxide in induction chemotherapy and the clinical outcome was favorable.