Isolated trisomy 13 defines a genetically homogenous AML subgroup with high frequency of mutations in spliceosome genes and poor prognosis
Menée sur 34 patients atteints d'une leucémie myéloïde aiguë avec trisomie 13, cette étude allemande identifie la présence fréquente de mutations d'un petit groupe de gènes
Isolated trisomy 13 (AML+13) is a rare chromosomal abnormality in acute myeloid leukemia (AML), and its prognostic relevance is poorly characterized. We analyzed the clinical course of 34 AML+13 patients enrolled in the German AMLCG-1999 and SAL trials and studied their biological characteristics by exome sequencing, targeted sequencing of candidate genes and gene expression profiling. Relapse-free (RFS) and overall survival (OS) of AML+13 patients were inferior compared to other ELN Intermediate-II patients (n=855) (median RFS, 7.8 vs 14.1 months, p=0.006; median OS 9.3 vs. 14.8 months, p=0.004). Besides the known high frequency of RUNX1 mutations (75%), we identified mutations in spliceosome components in 88%, including SRSF2 codon 95 mutations in 81%, of AML+13 patients. Moreover, recurring mutations were detected in ASXL1 (44%) and BCOR (25%). Two patients carried mutations in CEBPZ, suggesting that CEBPZ is a novel recurrently mutated gene in AML. Gene expression analysis revealed a homogenous expression profile including upregulation of FOXO1 and FLT3 and downregulation of SPRY2. This is the most comprehensive clinical and biological characterization of AML+13 to date, and reveals a striking clustering of lesions in a few genes, defining AML+13 as a genetically homogenous leukemia subgroup with alterations in a few critical cellular pathways. These studies were registered at clinicaltrials.gov, identifiers: AMLCG-1999: NCT00266136; AML96: NCT00180115; AML2003: NCT00180102; and AML60+: NCT00893373.