Publications by authors named "Adrian M Dubuc"

Prenatal diagnostic testing of amniotic fluid, chorionic villi, or more rarely, fetal cord blood is recommended following a positive or unreportable noninvasive cell-free fetal DNA test, abnormal maternal biochemical serum screen, abnormal ultrasound, or increased genetic risk for a cytogenomic abnormality based on family history. Although chromosomal microarray is recommended as the first-tier prenatal diagnostic test, in practice, multiple assays are often assessed in concert to achieve a final diagnostic result. The use of multiple methodologies is costly, time consuming, and labor intensive.

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Unlabelled: Relapse is the leading cause of death in patients with medulloblastoma, the most common malignant pediatric brain tumor. A better understanding of the mechanisms underlying recurrence could lead to more effective therapies for targeting tumor relapses. Here, we observed that SOX9, a transcription factor and stem cell/glial fate marker, is limited to rare, quiescent cells in high-risk medulloblastoma with MYC amplification.

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Accurate detection of copy number alterations (CNAs) has become increasingly important in clinical oncology for the purpose of diagnosis, prognostication, and disease management. Cytogenetic approaches for the detection of CNAs, including karyotype, fluorescence in situ hybridization (FISH), and chromosomal microarray, remain mainstays in clinical laboratories. Yet, with rapidly decreasing costs and improved accuracy of CNA detection using emerging technologies such as next-generation sequencing and optical genome mapping, we are approaching a new era of cytogenomics and molecular oncology.

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Article Synopsis
  • Cytogenetics is super important for understanding blood cancers and helps doctors see what’s happening in a person’s genes.
  • Scientists have developed new ways to study genes using modern sequencing technology, which can be better than traditional methods.
  • A team of experts is sharing ideas on how to use these new technologies worldwide to help make cancer diagnoses and treatments more effective.
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Background: Meningiomas are the most common primary intracranial tumor in adults. Clinical care is currently guided by the World Health Organization (WHO) grade assigned to meningiomas, a 3-tiered grading system based on histopathology features, as well as extent of surgical resection. Clinical behavior, however, often fails to conform to the WHO grade.

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Comprehensive characterization of somatic genomic alterations has led to fundamental shifts in our understanding of tumor biology. In clinical practice, these studies can lead to modifications of diagnosis and/or specific treatment implications, fulfilling the promise of personalized medicine. Herein, we describe a 78-yr-old woman under surveillance for long-standing untreated chronic lymphocytic leukemia (CLL).

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Article Synopsis
  • This study looked at different types of tumors in the prostate that may come from special cells in the tissue.
  • Researchers used advanced DNA and RNA testing on 25 tumors, finding many had genetic changes.
  • The findings suggest these tumors are very different from each other and may not fit into one specific type, leading to questions about how they should be diagnosed.
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Background: Giant cell glioblastoma (gcGBM) is a rare histologic subtype of glioblastoma characterized by numerous bizarre multinucleate giant cells and increased reticulin deposition. Compared with conventional isocitrate dehydrogenase (IDH)-wildtype glioblastomas, gcGBMs typically occur in younger patients and are generally associated with an improved prognosis. Although prior studies of gcGBMs have shown enrichment of genetic events, such as alterations, no defining aberrations have been identified.

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Aims: Methylthioadenosine phosphorylase (MTAP) immunohistochemical expression is a specific marker of CDKN2A deletion in malignant mesothelioma. However, the relationship of MTAP expression with MTAP copy number remains unexplored.

Methods And Results: Forty malignant pleural mesotheliomas were characterised by targeted next-generation sequencing (29), single-nucleotide polymorphism microarray (seven), or both (four).

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Summary: The expansion of targeted panel sequencing efforts has created opportunities for large-scale genomic analysis, but tools for copy-number quantification on panel data are lacking. We introduce ASCETS, a method for the efficient quantitation of arm and chromosome-level copy-number changes from targeted sequencing data.

Availability And Implementation: ASCETS is implemented in R and is freely available to non-commercial users on GitHub: https://github.

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Genetic analysis is a critical component in the male infertility workup. For male infertility due to oligospermia/azoospermia, standard guidelines recommend karyotype and Y-chromosome microdeletion analyses. A karyotype is used to identify structural and numerical chromosome abnormalities, whereas Y-chromosome microdeletions are commonly evaluated by multiplex PCR analysis because of their submicroscopic size.

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The distinction between lipoma and atypical lipomatous tumor can be challenging in some cases. While detection of MDM2 gene amplification via fluorescence in situ hybridization (FISH) has been well established as a diagnostic tool to distinguish atypical lipomatous tumor and well-differentiated liposarcoma from benign mimics, MDM2 RNA in situ hybridization (RNA-ISH) has recently been proposed as an alternative diagnostic assay. During clinical workup for lipomatous tumors using MDM2 RNA-ISH, we noticed several dysplastic lipomas that were positive for MDM2 RNA-ISH but negative for MDM2 amplification by FISH.

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Tumors of the central nervous system (CNS) have been historically classified according to their morphologic and immunohistochemical features. In 2016, updates to the classification of tumors of the CNS by the World Health Organization revolutionized this paradigm. For the first time, genomic findings, whether whole-arm chromosomal aberrations or single nucleotide variants, represent a necessary and critical component of diagnosis, contributing or superseding histologic findings.

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Philadelphia chromosome (Ph)-like acute lymphoblastic leukemia (ALL) is a subtype of Ph-negative ALL that molecularly resembles Ph-positive ALL. It shares the adverse prognosis of Ph-positive ALL, but lacks the BCR-ABL1 fusion oncogene. Instead, Ph-like ALL is associated with alternative mutations in signaling pathways.

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Ependymomas show poor correlation between World Health Organization grade and clinical outcome. A subgroup of supratentorial ependymomas are characterized by C11orf95-RELA fusions, presumed to be secondary to chromothripsis of chromosome 11, resulting in constitutive activation of the NF-κB signaling pathway and overexpression of cyclin D1, p65, and L1 cell adhesion molecule (L1CAM). These RELA-fused ependymomas are recognized as a separate, molecularly defined World Health Organization entity and might be associated with poor clinical outcome.

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Localized pleural mesothelioma is a rare solitary circumscribed pleural tumor that is microscopically similar to diffuse malignant pleural mesothelioma. However, the molecular characteristics and nosologic relationship with its diffuse counterpart remain unknown. In a consecutive cohort of 1110 patients with pleural mesotheliomas diagnosed in 2005-2018, we identified six (0.

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The detection of acquired copy-number abnormalities (CNAs) and copy-neutral loss of heterozygosity (CN-LOH) in neoplastic disorders by chromosomal microarray analysis (CMA) has significantly increased over the past few years with respect to both the number of laboratories utilizing this technology and the broader number of tumor types being assayed. This highlights the importance of standardizing the interpretation and reporting of acquired variants among laboratories. To address this need, a clinical laboratory-focused workgroup was established to draft recommendations for the interpretation and reporting of acquired CNAs and CN-LOH in neoplastic disorders.

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Medulloblastoma and central nervous system primitive neuroectodermal tumors (CNS-PNET) are aggressive, poorly differentiated brain tumors with limited effective therapies. Using () transposon mutagenesis, we identified novel genetic drivers of medulloblastoma and CNS-PNET. Cross-species gene expression analyses classified -driven tumors into distinct medulloblastoma and CNS-PNET subgroups, indicating they resemble human Sonic hedgehog and group 3 and 4 medulloblastoma and CNS neuroblastoma with activation.

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Purpose: Chromosomal microarray (CMA) is recommended as the first-tier test in evaluation of individuals with neurodevelopmental disability and congenital anomalies. CMA may not detect balanced cytogenomic abnormalities or uniparental disomy (UPD), and deletion/duplications and regions of homozygosity may require additional testing to clarify the mechanism and inform accurate counseling. We conducted an evidence review to synthesize data regarding the benefit of additional testing after CMA to inform a genetic diagnosis.

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Papillary tumor of the pineal region (PTPR) is a neuroepithelial neoplasm first described in 2003. Despite the anatomic association of PTPR with the pineal gland, the features of these tumors resemble those of the ependymal circumventricular subcommissural organ (SCO) of the posterior third ventricle. Given the presumed distinct derivation of PTPR and pineal parenchymal tumors, we hypothesized that expression of lineage-specific transcription factors could distinguish these tumors and provide additional insight into the differentiation of PTPR.

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Accurate and consistent variant classification is required for Precision Medicine. But clinical variant classification remains in its infancy. While recent guidelines put forth jointly by the American College of Medical Genetics and Genomics (ACMG) and Association of Molecular Pathology (AMP) for the classification of Mendelian variants has advanced the field, the degree of subjectivity allowed by these guidelines can still lead to inconsistent classification across clinical molecular genetic laboratories.

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Background: Clinical genomics platforms are needed to identify targetable alterations, but implementation of these technologies and best practices in routine clinical pediatric oncology practice are not yet well established.

Methods: Profile is an institution-wide prospective clinical research initiative that uses targeted sequencing to identify targetable alterations in tumors. OncoPanel, a multiplexed targeted exome-sequencing platform that includes 300 cancer-causing genes, was used to assess single nucleotide variants and rearrangements/indels.

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Comprehensive genomic profiling of a patient's cancer can be used to diagnose, monitor, and recommend treatment. Clinical implementation of tumor profiling in an enterprise-wide, unselected cancer patient population has yet to be reported. We deployed a hybrid-capture and massively parallel sequencing assay (OncoPanel) for all adult and pediatric patients at our combined cancer centers.

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