A De Novo 8q22.2q22.3 Interstitial Microdeletion in a Girl with Developmental Delay and Congenital Defects.

Background and Objectives: Only nine patients with interstitial de novo 8q22.2q22.3 microdeletions have been reported to date. The objective of this report is to present clinical features of a new patient with an 8q22.2q22.3 microdeletion, to compare her phenotype to other previously reported patients, and to further expand the phenotype associated with this microdeletion. Materials and Methods: We describe an 8½-year-old girl with developmental delay, congenital hip dysplasia, a bilateral foot deformity, bilateral congenital radioulnar synostosis, a congenital heart defect, and minor facial anomalies. Results: Chromosomal microarray analysis revealed a 4.9 Mb deletion in the 8q22.2q22.3 region. De novo origin was confirmed by real-time PCR analysis. Conclusions: Microdeletions in the 8q22.2q22.3 region are characterized by moderate to severe intellectual disability, seizures, distinct facial features and skeletal abnormalities. In addition to one already reported individual with an 8q22.2q22.3 microdeletion and unilateral radioulnar synostosis, this report of a child with bilateral radioulnar synostosis provides additional evidence, that radioulnar synostosis is not an incidental finding in individuals with an 8q22.2q22.3 microdeletion. Additional patients with similar microdeletions would be of a great importance for more accurate phenotypic description and further analysis of the genotypic-phenotypic relationship.

Low incidence of ABL-class and JAK-STAT signaling pathway alterations in uniformly treated pediatric and adult B-cell acute lymphoblastic leukemia patients using MRD risk-directed approach - a population-based study.

BACKGROUND: ABL-class and JAK-STAT signaling pathway activating alterations have been associated with both a poor post-induction minimal residual disease (MRD) response and an inferior outcome in B-cell acute lymphoblastic leukemia (B-ALL). However, in most of the studies patients received non-uniform treatment. METHODS: We performed a population-based analysis of 160 (122 pediatric and 38 adult) Lithuanian BCR-ABL1-negative B-ALL patients who had been uniformly treated according to MRD-directed NOPHO ALL-2008 protocol. Targeted RNA sequencing and FISH analysis were performed in cases without canonical B-ALL genomic alterations (high hyperdiploids and low hypodiploids included). RESULTS: We identified ABL-class fusions in 3/160 (1.9%) B-ALL patients, and exclusively in adults (p = 0.003). JAK-STAT pathway fusions were present in 4/160 (2.5%) cases. Of note, P2RY8-CRLF2 fusion was absent in both pediatric and adult B-ALL cases. Patients with ABL-class or JAK-STAT pathway fusions had a poor MRD response and were assigned to the higher risk groups, and had an inferior event-free survival (EFS) / overall survival (OS) compared to patients without these fusions. In a multivariate analysis, positivity for ABL-class and JAK-STAT fusions was a risk factor for worse EFS (p = 0.046) but not for OS (p = 0.278) in adults. CONCLUSIONS: We report a low overall frequency of ABL-class and JAK-STAT fusions and the absence of P2RY8-CRLF2 gene fusion in the Lithuanian BCR-ABL1 negative B-ALL cohort. Future (larger) studies are warranted to confirm an inferior event-free survival of ABL-class/JAK-STAT fusion-positive adult patients in MRD-directed protocols.

Outcomes of relapsed or refractory acute myeloid leukemia patients failing venetoclax-based salvage therapies.

OBJECTIVES AND METHODS: We conducted a retrospective analysis to evaluate the outcomes of 28 heavily pretreated (median 3 (2-6) treatment lines, sixteen (57%) allotransplanted) relapsed/refractory acute myeloid leukemia patients who had failed salvage venetoclax-based therapies. RESULTS: The median age was 59 years (20-80), 20 patients (71%) had ECOG 2-4 status, and 18 patients (64%) were stratified to European Leukemia Network 2017 adverse risk group. The most common mutations were ASXL1 (21%), RUNX1 (18%), FLT3 ITD/TKD (18%), PTPN11 (15%), NRAS/KRAS (15%), and WT1 (15%). Twenty-two patients (79%) received different post-venetoclax salvage therapies with the overall response rate of 23% (complete remission + morphological leukemia-free state). Three of six (50%) patients achieved complete remissions after therapy with venetoclax + actinomycin D ± low-dose cytarabine. The remaining 6 patients did not receive any further salvage treatment mainly due to poor general condition. The median overall survival was 3.9 months for all patients (4.3 for those receiving post-venetoclax salvage vs 1.3 months receiving palliative care alone, P < .001). CONCLUSIONS: Though the remission rate and survival of patients failing venetoclax are poor, a small proportion of these R/R AML patients may still respond to cautious intensification of chemotherapy with venetoclax.

A population-based single nucleotide polymorphism array analysis of genomic aberrations in younger adult acute lymphoblastic leukemia patients.

Adult acute lymphoblastic leukemia (ALL) is characterized by a high frequency of abnormal karyotypes some of which are related to outcome. Single nucleotide polymorphism (SNP) array analysis provides a highly sensitive platform to detect large and small genomic aberrations. SNP array profiling data in adult ALL are limited and further systematic studies of this patient group are needed. We performed a population-based SNP array analysis of genomic aberrations and their influence on survival in 66 Lithuanian 18-65 year old ALL patients diagnosed between 2007 and 2013. Most aberrations were detected in chromosome arm 9p, chromosome arm 6q, chromosome arm 13q, and chromosome 17. The recurrently targeted copy number abnormalities involved several leukemia-related genes-CDKN2A/B, MLL, IKZF1, PAX5, RB1, TP53, and ETV6. We identified several new recurrent aberrations with possible new target genes: SMARCA4 in 19p13.2, RNASEL in 1q25.3, ARHGEF12 in 11q23.3, and LYL1 in 19p13.2. Aberrations in chromosome 13 and the RB1 gene as well as CDKN2A/B gene status were related to the outcome.

Multiple Myeloma Immunophenotype Related to Chromosomal Abnormalities Used in Risk Assessment.

(1) Background: At diagnosis, multiplemyeloma risk estimation includes disease burden, end-organ damage, and biomarkers, with increasing emphasis on genetic abnormalities. Multicolor flow cytometry (MFC) is not always considered in risk estimation. We demonstrate associations found between genetic abnormalities and antigen expression of plasma cells measured by MFC. (2) Methods: Single nucleotide polymorphism microarray (SNP-A) karyotyping as well as MFC using standardized next-generation flow (NGF) panels and instrument settings were performed from bone marrow aspirates at the time of diagnosis. (3) Results: We uncovered specific immunophenotype features related to different genetic risk factors. Specifically, we found higher malignant/normal plasma cell ratio and lower expression of CD27, CD38, CD45, CD56, CD117 and CD138 in higher-risk genetic groups or risk categories.

Case Report: Specific ABL-Inhibitor Imatinib Is an Effective Targeted Agent as the First Line Therapy to Treat B-Cell Acute Lymphoblastic Leukemia With a Cryptic NUP214::ABL1 Gene Fusion.

Acute lymphoblastic leukemia (ALL) with recurrent genetic lesions, affecting a series of kinase genes, is associated with unfavorable prognosis, however, it could benefit from treatment with tyrosine kinase inhibitors (TKI). NUP214::ABL1 fusion is detected in 6% of T-cell acute lymphoblastic leukemia (T-ALL), and is very rare in B-ALL. We present a case of adolescent with B-ALL and a cryptic NUP214::ABL1 fusion which was initially missed during diagnostic screening and was detected by additional RNA sequencing. Treatment with specific ABL-inhibitor Imatinib was added later in therapy with a good effect. Initial treatment according to conventional chemotherapy was complicated by severe side effects. At the end of Consolidation, the patient was stratified to a high risk group with allogeneic hematopoietic stem cell transplantation because of insufficient response to therapy. At that time, targeted RNA sequencing detected NUP214::ABL1 gene fusion which was previously missed due to a small microduplication in the 9q34 chromosome region. Gene variant analysis revealed no TKI-resistant ABL1 mutations; therefore, treatment with Imatinib was added to target the NUP214::ABL1 fusion protein. A negative minimal residual disease was achieved, and treatment was downgraded to intermediate risk protocol. Combining routine genetic assays with next-generation sequencing methods could prevent from missing atypical gene alterations. Identification of rare targetable genetic subtypes is of importance in order to introduce targeted therapy as early as possible that may improve survival and reduce toxicity. Treatment with ABL1 inhibitor imatinib mesylate revealed as a highly effective targeted therapy against the leukemia driving protein kinase.

Population-based targeted RNA sequencing reveals novel disease-related gene fusions in pediatric and adult T-ALL.

BACKGROUND: T-cell acute lymphoblastic leukemia (T-ALL) is a genetically diverse disease characterized by a heterogeneous profile of genetic lesions. Recent transcriptome studies identified a number of new T-ALL-related gene fusions. Novel gene fusions could be employed as disease-specific molecular markers and provide a better understanding of T-ALL biology, proving the need for further omics sequencing studies. METHODS: We performed a population-based analysis of 65 (26 pediatric and 39 adults) Lithuanian T-ALL patients. Targeted RNA sequencing (RNA-seq) was used to detect recurrent and novel T-ALL-related fusion transcripts and gene sequence variants. RT-qPCR was used to calculate the relative gene expression of fusion transcripts. RESULTS: We identified disease-related gene alterations in 57/65 (87.7%) T-ALL cases, of which four patients harbored gene fusions that affect ABL-class or JAK-STAT signaling pathways. Five novel gene fusions were detected in 4/65 (6.2%) T-ALL cases: CD99::ABL2 and ZEB1::GNAS in the same case, CTCF::ENKD1, DIAPH1::JAK2, and CDK6::NEK1. Novel fusion transcripts encode chimeric proteins that can potentially affect T-cell proliferation, apoptosis, and help to maintain leukemic cells. Importantly, novel fusion transcripts were not detected in the clinical remission samples attributing these fusions to the leukemic compartment. CONCLUSIONS: We report a similar incidence rate of recurrent gene alterations affecting T-ALL-related molecular signaling pathways in both Lithuanian T-ALL patients and other T-ALL studies. Our data suggest that newly identified gene fusions are specific to leukemic T-cells and provide new molecular insights on T-ALL pathogenesis. Further research is needed to confirm these findings.

Opposite chromosome constitutions due to a familial translocation t(1;21)(q43;q22) in 2 cousins with development delay and congenital anomalies: A case report.

RATIONALE: Chromosomal rearrangements are the major cause of multiple congenital abnormalities and intellectual disability. PATIENT CONCERNS AND DIAGNOSIS: We report 2 first cousins with unbalanced chromosomal aberrations of chromosomes 1 and 21, resulting from balanced familial translocation. Chromosome microarray analysis revealed 8.5 Mb1q43q44 duplication/21q22.2q22.3 deletion and 6.8 Mb 1q43q44 deletion/21q22.2q22.3 duplication. Among other features, cognitive and motor development delay and craniofacial anomalies are present in both patients, whereas congenital heart defect and hearing impairment is only present in patient carrying 1q43q44 duplication/21q22.2q22.3 deletion. LESSONS: In this report, we provide detailed analysis of the phenotypic features of both patients as well as compare our data with previously published reports of similar aberrations and discuss possible functional effects of AKT3, CEP170, ZBTB18, DSCAM, and TMPRSS3 genes included in the deleted and/or duplicated regions. Partial trisomy 1q/monosomy 21q has only been reported once before, and this is the first report of partial monosomy 1q/trisomy 21q. The expressed phenotype of mirroring chromosomal aberrations in our patients supports the previous suggestion that the dosage effect of some of the genes included in deleted/duplicated regions may result in opposite phenotypes of the patients.