BACKGROUND: The BCR::ABL1 is a hallmark of chronic myeloid leukemia (CML) and is also found in acute lymphoblastic leukemia (ALL). Most genomic breaks on the BCR side occur in two regions - Major and minor - leading to p210 and p190 fusion proteins, respectively. METHODS: By multiplex long-distance PCR or next-generation sequencing technology we characterized the BCR::ABL1 genomic fusion in 971 patients (adults and children, with CML and ALL: pediatric ALL: n = 353; pediatric CML: n = 197; adult ALL: n = 166; adult CML: n = 255 patients) and designed "Break-App" web tool to allow visualization and various analyses of the breakpoints. Pearson's Chi-Squared test, Kolmogorov-Smirnov test and logistic regression were used for statistical analyses. RESULTS: Detailed analysis showed a non-random distribution of breaks in both BCR regions, whereas ABL1 breaks were distributed more evenly. However, we found a significant difference in the distribution of breaks between CML and ALL. We found no association of breakpoints with any type of interspersed repeats or DNA motifs. With a few exceptions, the primary structure of the fusions suggests non-homologous end joining being responsible for the BCR and ABL1 gene fusions. Analysis of reciprocal ABL1::BCR fusions in 453 patients showed mostly balanced translocations without major deletions or duplications. CONCLUSIONS: Taken together, our data suggest that physical colocalization and chromatin accessibility, which change with the developmental stage of the cell (hence the difference between ALL and CML), are more critical factors influencing breakpoint localization than presence of specific DNA motifs.

• MeSH
• akutní lymfatická leukemie * genetika   patologie   MeSH
• bcr-abl fúzové proteiny * genetika   MeSH
• body zlomu chromozomu * MeSH
• chronická myeloidní leukemie * genetika   patologie   MeSH
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• dopisy MeSH

Recent trials show 5-year survival rates >95% for ETV6::RUNX1 Acute Lymphoblastic Leukemia (ALL). Since treatment has many side effects, an overview of cumulative drug doses and intensities between eight international trials is presented to characterize therapy needed for cure. A meta-analysis was performed as a comprehensive summary of survival outcomes at 5 and 10 years. For drug dose comparison in non-high risk trial arms, risk group distribution was applied to split the trials into two groups: trial group A with ~70% (range: 63.5-75%) of patients in low risk (LR) (CCLSG ALL2004, CoALL 07-03, NOPHO ALL2008, UKALL2003) and trial group B with ~45% (range: 38.7-52.7%) in LR (AIEOP-BFM ALL 2000, ALL-IC BFM ALL 2002, DCOG ALL10, JACLS ALL-02). Meta-analysis did not show evidence of heterogeneity between studies in trial group A LR and medium risk (MR) despite differences in treatment intensity. Statistical heterogeneity was present in trial group B LR and MR. Trials using higher cumulative dose and intensity of asparaginase and pulses of glucocorticoids and vincristine showed better 5-year event-free survival but similar overall survival. Based on similar outcomes between trials despite differences in therapy intensity, future trials should investigate, to what extent de-escalation is feasible for ETV6::RUNX1 ALL.

• MeSH
• akutní lymfatická leukemie * genetika   farmakoterapie   mortalita   terapie   MeSH
• fúzní onkogenní proteiny * genetika   MeSH
• lidé MeSH
• míra přežití MeSH
• protein ETS, translokační varianta 6 * MeSH
• protein PEBP2A2 * genetika   MeSH
• protokoly antitumorózní kombinované chemoterapie terapeutické užití   MeSH
• protoonkogenní proteiny c-ets * genetika   MeSH
• represorové proteiny * genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• metaanalýza MeSH

• MeSH
• akutní lymfatická leukemie * genetika   diagnóza   MeSH
• chromozomální aberace * MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• dopisy MeSH

Minimal/measurable residual disease (MRD) diagnostics using real-time quantitative PCR analysis of rearranged immunoglobulin and T-cell receptor gene rearrangements are nowadays implemented in most treatment protocols for patients with acute lymphoblastic leukemia (ALL). Within the EuroMRD Consortium, we aim to provide comparable, high-quality MRD diagnostics, allowing appropriate risk-group classification for patients and inter-protocol comparisons. To this end, we set up a quality assessment scheme, that was gradually optimized and updated over the last 20 years, and that now includes participants from around 70 laboratories worldwide. We here describe the design and analysis of our quality assessment scheme. In addition, we here report revised data interpretation guidelines, based on our newly generated data and extensive discussions between experts. The main novelty is the partial re-definition of the "positive below quantitative range" category by two new categories, "MRD low positive, below quantitative range" and "MRD of uncertain significance". The quality assessment program and revised guidelines will ensure reproducible and accurate MRD data for ALL patients. Within the Consortium, similar programs and guidelines have been introduced for other lymphoid diseases (e.g., B-cell lymphoma), for new technological platforms (e.g., digital droplet PCR or Next-Generation Sequencing), and for other patient-specific MRD PCR-based targets (e.g., fusion genes).

• MeSH
• akutní lymfatická leukemie genetika   diagnóza   MeSH
• genová přestavba MeSH
• geny pro imunoglobuliny MeSH
• kvantitativní polymerázová řetězová reakce metody   normy   MeSH
• lidé MeSH
• reziduální nádor * genetika   diagnóza   MeSH
• směrnice pro lékařskou praxi jako téma normy   MeSH
• zajištění kvality zdravotní péče MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Syndrom Noonanové je časté dědičné onemocnění s heterogenním genetickým podkladem a velkou variabilitou v klinických projevech. Postižení pacienti mají kromě různých vrozených vad a abnormalit i zvýšené riziko rozvoje maligního onemocnění v dětském věku. V následujících kazuistikách prezentujeme dvě typické hematoonkologické diagnózy, pojící se se syndromem Noonanové - tranzientní myeloproliferativní poruchu a akutní lymfoblastickou leukemii. Odlišnosti v anamnéze, cestě k diagnóze i průběhu léčby hematoonkologického onemocnění nás navedly k hledání genetického podkladu potíží s následným potvrzením syndromu Noonanové.

Noonan syndrome is a common hereditary condition with a heterogeneous genetic background and great variability in clinical manifestations. In addition to various birth defects and abnormalities, the affected patients have also an increased risk of developing a malignant disease in childhood. In the following case reports, we present two typical hemato-oncological diagnoses associated with Noonan syndrome - transient myeloproliferative disorder and acute lymphoblastic leukemia. Differences in the case history, diagnostic process and the course of treatment led us to search for the genetic basis of the difficulties with the subsequent confirmation of Noonan's syndrome.

• MeSH
• akutní lymfatická leukemie diagnóza   genetika   terapie   MeSH
• genetické testování MeSH
• hematologické nádory * etiologie   genetika   patologie   MeSH
• juvenilní myelomonocytární leukemie patologie   terapie   MeSH
• kojenec MeSH
• leukocytóza etiologie   terapie   MeSH
• lidé MeSH
• myeloproliferativní poruchy diagnóza   genetika   patologie   terapie   MeSH
• nádory diagnóza   klasifikace   patologie   MeSH
• Noonanové syndrom * diagnóza   komplikace   patologie   MeSH
• předškolní dítě MeSH
• riziko MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• kazuistiky MeSH

• MeSH
• akutní lymfatická leukemie * genetika   MeSH
• genová přestavba MeSH
• lidé MeSH
• pre-B-buněčná leukemie * genetika   MeSH
• retrospektivní studie MeSH
• transkripční faktory MEF2 MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

• MeSH
• akutní lymfatická leukemie * genetika   MeSH
• lidé MeSH
• mutace MeSH
• nádorový supresorový protein p53 genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• akutní lymfatická leukemie * farmakoterapie   genetika   MeSH
• bcr-abl fúzové proteiny genetika   MeSH
• lidé MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• dopisy MeSH
• práce podpořená grantem MeSH

We compared minimal/measurable residual disease (MRD) levels evaluated by routinely used real-time quantitative polymerase chain reaction (qPCR) patient-specific assays and by next-generation sequencing (NGS) approach in 780 immunoglobulin (IG) and T-cell receptor (TR) markers in 432 children with B-cell precursor acute lymphoblastic leukemia treated on the AIEOP-BFM ALL 2009 protocol. Our aim was to compare the MRD-based risk stratification at the end of induction. The results were concordant in 639 of 780 (81.9%) of these markers; 37 of 780 (4.7%) markers were detected only by NGS. In 104 of 780 (13.3%) markers positive only by qPCR, a large fraction (23/104; 22.1%) was detected also by NGS, however, owing to the presence of identical IG/TR rearrangements in unrelated samples, we classified those as nonspecific/false-positive. Risk group stratification based on the MRD results by qPCR and NGS at the end of induction was concordant in 76% of the patients; 19% of the patients would be assigned to a lower risk group by NGS, largely owing to the elimination of false-positive qPCR results, and 5% of patients would be assigned to a higher risk group by NGS. NGS MRD is highly concordant with qPCR while providing more specific results and can be an alternative in the front line of MRD evaluation in forthcoming MRD-based protocols.

• MeSH
• akutní lymfatická leukemie * diagnóza   genetika   terapie   MeSH
• dítě MeSH
• genová přestavba MeSH
• hodnocení rizik MeSH
• imunoglobuliny genetika   MeSH
• lidé MeSH
• pre-B-buněčná leukemie * diagnóza   genetika   terapie   MeSH
• receptory antigenů T-buněk genetika   MeSH
• reziduální nádor diagnóza   genetika   MeSH
• vysoce účinné nukleotidové sekvenování metody   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Chromosomal rearrangements of the human KMT2A/MLL gene are associated with de novo as well as therapy-induced infant, pediatric, and adult acute leukemias. Here, we present the data obtained from 3401 acute leukemia patients that have been analyzed between 2003 and 2022. Genomic breakpoints within the KMT2A gene and the involved translocation partner genes (TPGs) and KMT2A-partial tandem duplications (PTDs) were determined. Including the published data from the literature, a total of 107 in-frame KMT2A gene fusions have been identified so far. Further 16 rearrangements were out-of-frame fusions, 18 patients had no partner gene fused to 5'-KMT2A, two patients had a 5'-KMT2A deletion, and one ETV6::RUNX1 patient had an KMT2A insertion at the breakpoint. The seven most frequent TPGs and PTDs account for more than 90% of all recombinations of the KMT2A, 37 occur recurrently and 63 were identified so far only once. This study provides a comprehensive analysis of the KMT2A recombinome in acute leukemia patients. Besides the scientific gain of information, genomic breakpoint sequences of these patients were used to monitor minimal residual disease (MRD). Thus, this work may be directly translated from the bench to the bedside of patients and meet the clinical needs to improve patient survival.

• MeSH
• akutní lymfatická leukemie * genetika   MeSH
• akutní myeloidní leukemie * genetika   MeSH
• dítě MeSH
• dospělí MeSH
• fúze genů MeSH
• histonlysin-N-methyltransferasa * genetika   MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• předškolní dítě MeSH
• protoonkogenní protein MLL * genetika   MeSH
• senioři MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• předškolní dítě MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH