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Genetic testing plays a central role in myelodysplastic neoplasms (MDS) diagnosis, prognosis, and therapeutic decisions. The widely applied cytogenetic revised international prognostic scoring system (IPSS-R) was based on chromosome banding analysis (CBA). However, subsequently developed genetic methodologies, such as single nucleotide polymorphism (SNP) array, demonstrated to be a valid alternative test for MDS. SNP array is, in fact, able to detect the majority of MDS-associated cytogenetic aberrations, by providing further genomic information due to its higher resolution. In this study, 290 samples from individuals with a confirmed or suspected diagnosis of MDS were tested by both CBA and SNP array, in order to evaluate and compare their cytogenetic IPSS-R score in the largest MDS cohort reported so far. A concordant or better refined cytogenetic IPSS-R array-based score was obtained for 95% of cases (277). Therefore, this study confirms the effective applicability of SNP array toward the cytogenetic IPSS-R evaluation and consequently, toward the molecular international prognostic scoring system for MDS (IPSS-M) assessment, which ensures an improved MDS risk stratification refinement. Considering the advent of additional genetic technologies interrogating the whole genome with increased resolutions, counting cytogenetic abnormalities based on their size may result in a simplistic approach. On the contrary, assessing overall genomic complexity may provide additional crucial information. Independently of the technology used, genetic results should indeed aim at ensuring a highly refined stratification for MDS patients., (© 2023 The Authors. Genes, Chromosomes and Cancer published by Wiley Periodicals LLC.)

Complex karyotype (CK) identified by chromosome-banding analysis (CBA) has shown prognostic value in chronic lymphocytic leukemia (CLL). Genomic arrays offer high-resolution genome-wide detection of copy-number alterations (CNAs) and could therefore be well equipped to detect the presence of a CK. Current knowledge on genomic arrays in CLL is based on outcomes of single center studies, in which different cutoffs for CNA calling were used. To further determine the clinical utility of genomic arrays for CNA assessment in CLL diagnostics, we retrospectively analyzed 2293 arrays from 13 diagnostic laboratories according to established standards. CNAs were found outside regions captured by CLL FISH probes in 34% of patients, and several of them including gains of 8q, deletions of 9p and 18p (p<0.01) were linked to poor outcome after correction for multiple testing. Patients (n=972) could be divided in three distinct prognostic subgroups based on the number of CNAs. Only high genomic complexity (high-GC), defined as ≥5 CNAs emerged as an independent adverse prognosticator on multivariable analysis for time to first treatment (Hazard ratio: 2.15, 95% CI: 1.36-3.41; p=0.001) and overall survival (Hazard ratio: 2.54, 95% CI: 1.54-4.17; p<0.001; n=528). Lowering the size cutoff to 1 Mb in 647 patients did not significantly improve risk assessment. Genomic arrays detected more chromosomal abnormalities and performed at least as well in terms of risk stratification compared to simultaneous chromosome banding analysis as determined in 122 patients. Our findings highlight genomic array as an accurate tool for CLL risk stratification.

Myelodysplastic syndromes (MDS) are a heterogeneous group of diseases, with a variable probability of transformation into acute leukemia, which is, in the vast majority of cases, of myeloid lineage. Nevertheless, rare cases of acute lymphoblastic leukemia in patients with previously diagnosed MDS have been reported. We describe a series of 3 cases of MDS/CMML marked with evolution to acute lymphoblastic leukemia (ALL) and provide a comprehensive review of the 49 cases documented in the literature so far. These sporadic events have only been published as single-case reports or small series to date. Such atypical cases emphasize the possibility of major phenotypic switches arising at the leukemic stem cell (LSC) and/or early progenitor levels, as a consequence of epigenetic and genomic events driving these changes in the bone marrow niche.

Reciprocal RUNX1 fusions are traditionally found in up to 10% of acute myeloid leukemia (AML) patients, usually associated with a translocation (8;21)(q22;q22) corresponding to the RUNX1-RUNX1T1 fusion gene. So far, alternative RUNX1 rearrangements have been reported only rarely in AML, and the few reports so far have focused on results based on cytogenetics, fluorescence in situ hybridization, and polymerase chain reaction. Acknowledging the inherent limitations of these diagnostic techniques, the true incidence of rare RUNX1 rearrangements may be underestimated. In this report, we present two cases of adult AML, in which we detected rare RUNX1 rearrangements not by conventional cytogenetics but rather by next-generation panel sequencing. These include t(16;21)(q24;q22)/RUNX1-CBFA2T3 and t(7;21)(p22;q22)/RUNX1-USP42, respectively. In both patients the AML was therapy-related and associated with additional structural and numerical alterations thereby conferring bad prognosis. This is in line with previous reports on rare RUNX1 fusions in AML and emphasizes the clinical importance of their detection. In summary, our report not only confirms the clinical utility of NGS for diagnostics of rare reciprocal rearrangements in AML in a real-life scenario but also sheds light on the variety and complexity within AML. It further emphasizes the need for collection of additional cases for deepening insights on their clinical meaning as well as their frequency., (© 2019 Wiley Periodicals, Inc.)