Search PubMedSearch

SEARCH · Search PubMed

Results for “aneuploidy”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

Chromosome-scale genome remodeling in tumor evolution: Copy number alterations and structural variants as two sides of the same coin.

Chromosome-scale genomic rearrangements are a dominant force in tumor evolution. Copy-number alterations (CNAs) and structural variants (SVs) constitute two complementary axes of this process. Although detection technologies now deliver near-comprehensive catalogs, technical resolution has outpaced conceptual integration. In this review, we frame CNAs and SVs as inextricable facets of chromosomal aberrations. They reshape cancer genomes through altered gene dosage and three-dimensional regulatory rewiring. CNAs quantify the gene-dosage imbalance, yet arise through mechanistically distinct routes. Segmental CNAs typically require chromosomal breakage, and therefore often coincide with SV junctions. By contrast, whole-chromosome aneuploidy and whole-genome doubling (WGD) primarily reflect mitotic or cytokinetic failure and can occur without local breakpoints, while nevertheless reshaping the karyotypic landscape and seeding subsequent structural complexity. SVs, in turn, range from unbalanced events that alter copy number to ostensibly balanced exchanges that predominantly rewire regulatory architecture. Despite their diverse and sometimes catastrophic architectures, SVs are ultimately rooted in double-strand break formation and error-prone resolution. By integrating CNAs and SVs within a unified mechanistic and functional framework, we aim to convert catalogs into concepts and distill the organizing principles that govern tumor genome evolution.

Humans

Meiotic Origins of Non-Mosaic Klinefelter Syndrome (47, XXY): Mechanisms, Dimorphism, and Emerging Genetic Susceptibility.

BACKGROUND: Non-mosaic Klinefelter syndrome (47,XXY) arises from sex-specific meiotic mechanisms leading to nondisjunction during gametogenesis. In maternal cases, errors occur predominantly during meiosis I, frequently involving X chromosomes that lack crossovers or exhibit crossovers outside optimal chromosomal locations; this nondisjunction is further exacerbated by advancing maternal age and the subsequent deterioration of cohesins. Conversely, paternal 47,XXY stems primarily from the failure of obligate recombination within the pseudoautosomal region, which is critical for accurate XY segregation. OBJECTIVE: Drawing on the latest literature, this review transitions from a descriptive account of non-mosaic Klinefelter syndrome (nKS) toward a comprehensive analysis of mechanistic and genomic evidence, establishing a unified framework of sex-specific meiotic vulnerability. METHODS: We synthesized recent findings from forward genetic approaches in mouse models with data from human observational and reverse-genetic studies, delineating an updated view of the established and putative mechanisms that modulate sex chromosome segregation. RESULTS: We frame XX and XY nondisjunction as a genetically modulated process rather than a purely stochastic event. The integrated evidence supports a unified framework in which maternal and paternal mechanisms converge primarily on meiotic recombination failure but differ in timing, chromosomal context, and genetic modulation. CONCLUSIONS: From a clinical standpoint, identifying the molecular drivers of sex chromosome aneuploidy will enhance genetic counseling and risk stratification. Such insights are poised to facilitate informed reproductive decision-making and timely therapeutic support, ultimately reducing the burden of nKS comorbidities and improving patients' quality of life.

aneuploidy

Visualization using NIPTviewer support the clinical interpretation of noninvasive prenatal testing results.

BACKGROUND: Noninvasive prenatal testing (NIPT) is increasingly used to screen for fetal chromosomal aneuploidy by analyzing cell-free DNA (cfDNA) in peripheral maternal blood. The method provides an opportunity for early detection of large genetic abnormalities without an increased risk of miscarriage due to invasive procedures. Commercial applications for use at clinical laboratories often take advantage of DNA sequencing technologies and include the bioinformatic workup of the sequence data. The interpretation of the test results and the clinical report writing, however, remains the responsibility of the diagnostic laboratory. In order to facilitate this step, we developed NIPTviewer, a web-based application to visualize and guide the interpretation of NIPT data results. RESULTS: NIPTviewer has a database functionality to store the NIPT results and a web interface for user interaction and visualization. The application has been implemented as part of a novel analysis pipeline for NIPT in a diagnostic laboratory at Uppsala University Hospital. The validation data set included 84 previously analyzed plasma samples with known results regarding chromosomes 13, 18, 21, X and Y. They were sequenced in six different experiments, uploaded to NIPTviewer and assigned to a clinical laboratory geneticist for interpretation. The results of all previously analyzed samples were replicated. CONCLUSION: NIPTviewer facilitates NIPT results interpretation and has been implemented as part of a NIPT analysis routine that was accredited by the national accreditation body for Sweden (Swedac).

Humans

Chromosome duplication causes premature aging via defects in ribosome quality control.

Down syndrome, caused by an extra copy of Chromosome 21, causes lifelong problems. One of the most common phenotypes among people with Down syndrome is premature aging, including early tissue decline, neurodegeneration, and shortened life span. Yet the reasons for premature systemic aging are a mystery and difficult to study in humans. Here we show that chromosome amplification in wild yeast also produces premature aging and shortens life span. Chromosome duplication disrupts nutrient-induced cell-cycle arrest, entry into quiescence, and cellular health during chronological aging, across genetic background and independent of which chromosome is amplified. Using a genomic screen, we discovered that these defects are due in part to aneuploidy-induced dysfunction in Ribosome Quality Control (RQC). We show that aneuploids entering quiescence display aberrant ribosome profiles, accumulate RQC intermediates, and harbor an increased load of protein aggregates compared to euploid cells. Although they maintain proteasome activity, aneuploids also show signs of ubiquitin dysregulation and sequestration into foci. Remarkably, inducing ribosome stalling in euploids produces similar aging phenotypes, while up-regulating limiting RQC subunits or poly-ubiquitin alleviates many of the aneuploid defects. We propose that the increased translational load caused by having too many mRNAs accelerates a decline in translational fidelity, contributing to premature aging.

Ribosomes

Generation of Aneuploid Human Induced Pluripotent Stem Cells from Primary Amniotic Fluid Cells via Episomal Plasmid Electroporation.

The generation of patient-specific induced pluripotent stem cells (iPSCs) from amniotic fluid cells (AFCs) carrying defined chromosomal aneuploidies provides a powerful platform for modeling genetic disorders. However, establishing a reliable and reproducible reprogramming pipeline for aneuploid AFCs remains technically challenging due to the intrinsic genomic instability and variable proliferative capacity of these cells. Here, we present a comprehensive, non-integrating method for generating aneuploid human iPSCs from primary AFCs using episomal plasmid electroporation. This protocol details the complete workflow, encompassing cell thawing and expansion with a gradual media adaptation strategy, optimized plasmid delivery via electroporation system, sequential post-electroporation culture with mesenchymal-to-epithelial transition (MET)-directed media changes, and mechanical colony picking based on defined morphological criteria. We further describe validation procedures, including immunofluorescence staining for core pluripotency markers, G-banding karyotype analysis to confirm aneuploid karyotype maintenance, and PCR-based episomal vector clearance verification. This feeder-free, integration-free protocol yields aneuploid iPSC lines suitable for disease modeling, drug screening, and studies of chromosome biology.

Humans

Engineering the Vero Cell Lineage: Toward a Programmable Vaccine Manufacturing Platform.

Vero cells remain an indispensable continuous substrate for human viral vaccine manufacturing. Despite decades of empirical process optimization, intrinsic genomic instability, including segmental aneuploidy and dynamic chromatin rearrangements, continues to limit the durability of engineered phenotypes under sustained viral burden and bioreactor stress. Here, we review the expanding engineering toolkit for the Vero lineage across a three-layered functional framework: the membrane interface, cytoplasmic foundry, and nuclear blueprint, evaluating translational prospects at each level. Receptor transplantation and morphological reprogramming have broadened viral entry range and enabled suspension-adapted culture formats, while metabolic flux management and temporally controlled apoptosis modulation have addressed intracellular production bottlenecks, albeit often with trade-offs between productivity, biosafety, and long-term population stability. At the genomic level, targeted perturbations of transcriptional regulators and emerging epigenetic interventions offer more durable gains, yet expression drift, clonal heterogeneity, and karyotypic instability during extended passaging highlight the need for locus-level precision rather than constitutive trait installation. Looking forward, infection-responsive dynamic logic circuits and the systematic identification of Vero-specific genomic safe harbors could shift the paradigm toward a conditionally responsive manufacturing architecture. Collectively, these advances suggest a pathway for transitioning the Vero lineage from a passive, empirically optimized biological substrate into a conditionally responsive, genomically stable, and programmable platform for modern vaccine preparedness.

Vero cells

The Use of APC/C Antagonists to Promote Mitotic Catastrophe in Cancer Cells.

The multiprotein subunit E3 ubiquitin ligase Anaphase-Promoting Complex/Cyclosome (APC/C) plays a key role in the control of mitosis progression. APC/C is the ultimate effector of the Spindle Assembly Checkpoint (SAC), the signaling system of higher organisms including the human that monitors the proper attachment of chromosomes to microtubules during cell division. Defects in this process result in genome instability, aneuploidy, premature aging, and cancer. APC/C roles in the SAC require its activation by the protein Cdc20. Interfering with APC/C activation by Cdc20 impairs APC/C substrate recognition, resulting in a delayed mitotic exit and eventually inducing cell death. This may be advantageous for the treatment of cancer and malignancies associated with SAC dysregulation. Here we describe a protocol to interfere with mitotic exit through the use of commercially available (Apcin, proTAME) as well as innovative small molecules we have developed that function as antagonists of APC/C activation by Cdc20. We show that the use of these molecules alone and in combination is effective to promote mitotic catastrophe and suppress cell expansion in 2D and 3D (spheroids) cancer cells of different tissue origin, including breast, cervical, and ovarian cancer.

Humans

Overexpression of GFP Fusions of Regulators of the SAC from Arabidopsis thaliana.

Cell division is a fundamental biological process, essential for sustaining life on Earth. Accurate replication followed by uniform segregation of the genome is required to ensure cell division is sustainable and reduces the likelihood of aneuploidy. The cell cycle has various checkpoints to safeguard proper replication, for example, the spindle assembly checkpoint (SAC) which ensures that all chromosomes are correctly aligned and attached to the spindle, before the transition to anaphase. The precise function of the SAC and SAC components in plants is so far unclear. First, the high level of polyploidy in plants raises concerns about the efficacy of the SAC. Second, many plant SAC components are implicated in other cellular processes, such as MAD1, which has been implicated in the reproductive transition of Arabidopsis thaliana. Overexpression of GFP fusions of core SAC components provides a key route to establish the functions of the different SAC components in plants. Here we describe two methods for agrobacterium-mediated transformation of plants.

Arabidopsis

From family trials to genomic mate allocation: statistical and genomic strategies to accelerate sugarcane genetic improvement.

Sugarcane (Saccharum spp.) underpins global sugar and bioenergy supply and is increasingly valued as a renewable biomass feedstock. Sustained improvement in commercial traits and resilience is constrained by long breeding cycles, clonal propagation, multi-stage testing, and a highly polyploid, heterozygous, and frequently aneuploid genome with substantial non-additive genetic variation. Genomic selection has demonstrated value for predicting elite-clone performance, yet its operational use remains limited at earlier decision points, including family selection, parent evaluation, and cross design. This review examines the biological, statistical, and genomic factors that shape these decisions, with emphasis on the Australian breeding context based on progeny assessment trials (PATs), clonal assessment trials (CATs), and final assessment trials (FATs). We evaluate challenges arising from family plot means, the use of different full-sib samples as nominal family replicates, spatial heterogeneity, competition, genotype-by-environment interaction, and the partitioning of additive and non-additive effects. We also assess the integration of pedigree and genomic relationship, genotype representation, allele-dosage estimation, aneuploidy, genomic prediction models, and training-population design. We then consider genomic prediction of cross performance and constrained mate allocation as approaches for improving expected family performance, accounting for cross-specific non-additive effects and managing relatedness. We propose a decision-centred framework that links family and clonal data across breeding stages, tracks the propagation of information and uncertainty, and supports parent recycling and cross allocation. We conclude with a practical research agenda for stage-integrated mixed-model and single-step analyses that connect early family evaluation with genomic prediction and cross-level decision support in sugarcane breeding.

Saccharum

Preserving centromere identity: right amounts of CENP-A at the right place and time.

Four decades ago, the discovery of centromere protein-A (CENP-A) marked a pivotal breakthrough in chromosome biology, revealing the epigenetic foundation of centromere identity. CENP-A, a histone H3 variant, directs the formation of the microtubule-binding kinetochore complex, designating the chromosomal site for its assembly and underpins the accurate partitioning of genetic material during cell division. Errors in cell division can give rise to DNA instability and aneuploidy, implicated in human diseases such as cancer. Therefore, discovering the underlying pathways and mechanisms responsible for the formation, regulation and maintenance of the centromere is important to our understanding of genome stability, epigenetic inheritance, and in providing the knowledge to help generate possible treatments and therapeutics. Here, we review various molecular pathways and mechanisms implicated in maintaining centromere identity and highlight some of the key outstanding questions with a focus on the human centromere.

Humans

Pan-cancer analysis identifies APOC1 as a TAM-derived modulator of adaptive immune resistance and predictor of therapeutic response.

BACKGROUND: Apolipoprotein C1 (APOC1) has been implicated in several malignancies, yet its expression patterns, clinical significance, and immunomodulatory roles across cancer types remain poorly characterized. METHODS: We performed a comprehensive multi-omic analysis of APOC1 across 33 cancer types integrating transcriptomic, proteomic, genomic, epigenomic, and pharmacogenomic data from TCGA, GTEx, CPTAC, and multiple independent external cohorts. Immune infiltration was assessed using seven complementary algorithms. Spatial transcriptomics and single-cell RNA sequencing were employed to determine the cellular source of APOC1 expression. RESULTS: APOC1 upregulation in most cancers was associated with cancer type-specific prognosis. After adjustment for clinical covariates and macrophage infiltration, high APOC1 remained an independent adverse factor in KIRC, LGG, and STAD. APOC1 expression positively correlated with genomic instability hallmarks, including homologous recombination deficiency and aneuploidy, with these associations largely independent of immune infiltration; in contrast, associations with tumor mutational burden were substantially confounded by macrophage abundance. Immune infiltration analysis revealed a pattern consistent with adaptive immune resistance: APOC1 correlated positively with immune-activating signatures (STAT1, MHC-II, TCR signaling) and immunosuppressive M2 macrophages and Tregs, yet negatively with anti-tumor effectors (activated NK cells, dendritic cells). Spatial transcriptomics and single-cell RNA sequencing identified tumor-associated macrophages (TAMs) as the primary cellular source of APOC1, with transcripts co-localizing with CD68 in tissue sections. APOC1 expression correlated with multiple immune checkpoint molecules and was elevated in responders to immune checkpoint blockade, consistent with an inflamed yet regulated tumor microenvironment. Pharmacogenomic analyses revealed that APOC1-high tumors display distinct drug response profiles, characterized by resistance to MAPK pathway inhibitors and potential sensitivity to the HDAC inhibitor Entinostat. CONCLUSION: This pan-cancer analysis establishes APOC1 as a context-dependent biomarker and a TAM-derived modulator of adaptive immune resistance, with prognostic and therapeutic implications across malignancies. APOC1-expressing TAMs represent a potential target for combination immunotherapy strategies.

APOC1

Cohesin variants associated with human reproductive and developmental disorders.

The cohesin complex is an evolutionarily conserved multi-subunit protein assembly essential for sister chromatid cohesion, meiotic recombination, DNA double-strand break repair, and transcriptional regulation. Pathogenic variants in its subunits are implicated in a spectrum of reproductive and developmental disorders, including non-obstructive azoospermia, premature ovarian insufficiency, reproductive aging, aneuploidy, Cornelia de Lange syndrome, Roberts syndrome, cancer, and neuropsychiatric disease. Consequently, identifying cohesin mutations is a priority for precision diagnostics and personalized medicine. This review systematically summarizes the cohesin variants linked to these pathologies, exploring their molecular mechanisms and clinical manifestations. A deeper understanding of these variants is crucial not only for deciphering disease etiology but also for guiding the development of targeted diagnostic strategies and therapeutic interventions, ultimately improving patient management and outcomes.

Humans

A Comprehensive Survey and Evaluation of Preimplantation Genetic Testing Practices in Canadian Assisted Reproductive Technology Clinics.

OBJECTIVES: In Canada, access to provincial funding for fertility treatments, such as in vitro fertilization (IVF) and preimplantation genetic testing (PGT), vary significantly. Despite rising demands, the lack of data on current practices across Canadian assisted reproductive technology (ART) clinics has contributed to the absence of standardized guidelines to support clinics offering these services. This pilot study surveys fertility clinics to examine current demands and practices related to PGT, while also exploring providers' perspectives on its implementation and future applications. METHODS: A 40-question survey was distributed to Canadian ART clinics offering IVF and PGT services. RESULTS: The responses confirm that there is a high demand for IVF and PGT services. Although clinical criteria for PGT for aneuploidy (PGT-A) were generally consistent across clinics, views on its effectiveness and eligibility for public funding varied. PGT for monogenic disorders (PGT-M) appears to be widely available, and respondents showed strong support for public funding in cases involving serious heritable conditions. CONCLUSIONS: This study outlines current practice and highlights variations across clinics, while also presenting the perspectives of providers of ART clinics throughout Canada. It also provides a degree of foresight as to the direction the PGT practice may take in the coming years.

assisted reproductive technology

Putative glioblastoma origin-like cells in the subventricular zone: isolation and characterization.

Glioblastoma (GBM) remains lethal despite maximal therapy. The adult subventricular zone (SVZ), a neural stem-cell niche, has been implicated as a potential site of origin, yet the identity and functional properties of putative GBM origin-like cells (GBM-OCs) within the SVZ remain unclear. An SVZ-restricted somatic mutation mouse model (Cre-induced EGFRvIII expression with Trp53 and Pten disruption) was established and mouse SVZ-derived cells were prospectively isolated for functional and molecular profiling. Self-renewal, multipotency, invasive potential and tumour-initiating capacity were assessed relative to control SVZ cells and matched tumour-derived tumourspheres. Whole-genome and RNA sequencing defined genomic and transcriptional alterations during early progression. Mouse GBM-OCs exhibited self-renewal and multilineage differentiation and initiated tumours only after re-implantation into the SVZ (11/29, 38%), whereas direct striatal implantation failed (0/25, 0%), indicating context-dependent tumorigenic potential associated with the SVZ microenvironment. In contrast, tumour-derived tumourspheres retained tumorigenic capacity upon implantation into both the SVZ and the striatum. During progression from mouse GBM-OCs to tumours, whole-chromosome and arm-level aneuploidies accumulated. In patients with GBM, multi-region single-nucleus RNA sequencing of tumour-free SVZ, matched tumours and tumour-free cortex identified rare neural stem cell-like, astrocyte-like and oligodendrocyte precursor-like SVZ populations transcriptionally aligned with GBM programmes. These cells showed single-nucleus RNA-inferred chromosome 7 gain and/or chromosome 10 loss signals, with concordant low-frequency copy-number alterations in the SVZ detected by exome sequencing and enriched in matched tumours. Together, these findings support the presence of SVZ-resident stem or progenitor-like populations with early GBM-associated features, consistent with putative GBM-OCs, and highlight the SVZ niche as a potential target for early detection and niche-informed therapeutic strategies.

Animals

Whole-genome sequencing reveals progressive versus stable myeloma precursor conditions as two distinct entities.

Multiple myeloma (MM) is consistently preceded by precursor conditions recognized clinically as monoclonal gammopathy of undetermined significance (MGUS) or smoldering myeloma (SMM). We interrogate the whole genome sequence (WGS) profile of 18 MGUS and compare them with those from 14 SMMs and 80 MMs. We show that cases with a non-progressing, clinically stable myeloma precursor condition (n = 15) are characterized by later initiation in the patient's life and by the absence of myeloma defining genomic events including: chromothripsis, templated insertions, mutations in driver genes, aneuploidy, and canonical APOBEC mutational activity. This data provides evidence that WGS can be used to recognize two biologically and clinically distinct myeloma precursor entities that are either progressive or stable.

DNA Copy Number Variations

Highly efficient base editing at PCSK9 and normal human embryo development.

Cas9-based tools enable programmable DNA lesions for studying repair outcomes, gene function, and genome correction. In human embryos, Cas9-induced DNA double-strand breaks are genotoxic, causing frequent aneuploidy and large deletions1,2. Here, we evaluate DNA repair outcomes at nicks and mismatches introduced by base editors at the PCSK9 and HBG loci in human embryos. Delivering ABE8e-V106W as a protein at fertilization achieved editing at all PCSK9 alleles, supporting development to the blastocyst stage and the derivation of homozygous edited stem cell lines. No insertions or deletions were detected, although rare on-target chromosome breakage and chromosomal abnormalities occurred. Nevertheless, editing at bystander and off-target sites was mosaic, and the introduction of the editor as mRNA caused frequent embryo arrest due to guide-independent deaminase activity. Thus, unlike Cas9-induced DNA breaks, base editor-induced lesions are efficiently repaired. However, undesirable consequences for the genome and development can occur, currently precluding clinical use in reproduction.

Journal Article

Rapid derivation of cloning-competent cells from peripheral blood advances conservation biobanking.

Establishing viable cell lines from endangered species is essential for conservation, yet traditional fibroblast derivation from skin biopsies faces challenges including contamination risk and extended culture timelines. Here, we demonstrate that endothelial progenitor cells (EPCs) and pericytes isolated from peripheral blood represent robust alternatives to fibroblasts for biobanking. Compared to canid fibroblasts, canid blood-derived cells exhibit 2- to 3-fold faster doubling rates (15 to 20 h vs. ~35 h for fibroblasts) and reduced time to banked cell lines (1.5 to 2 wks vs. 3 to 4 wks for fibroblasts). Proteomic profiling of 32 canonical markers confirmed EPCs and pericytes represent distinct populations with lineage-specific molecular signatures. Optical genome mapping demonstrated equivalent genomic stability across cell types with no detectable structural variants or aneuploidies. Finally, interspecific somatic cell nuclear transfer (iSCNT) experiments confirmed both EPCs and pericytes generate viable canid embryos with efficiency meeting or exceeding fibroblasts. As a proof of concept for conservation cloning, iSCNT embryos made with gray wolf blood-derived cells had a 15% implantation rate following embryo transfer and resulted in six viable fetuses. These findings support integrating blood-derived cell banking into conservation programs, which enables opportunistic genetic preservation during standard management activities and expands options for genetic rescue through assisted reproductive technologies.

Animals

Tracing the evolution and genomic dynamics of mating-type loci in Cryptococcus pathogens and closely related species.

Sexual reproduction in basidiomycete fungi is governed by MAT loci (P/R and HD), which exhibit remarkable evolutionary plasticity, characterized by expansions, rearrangements, and gene losses often associated with mating system transitions. The sister genera Cryptococcus and Kwoniella provide a powerful framework for studying MAT loci evolution owing to their diverse reproductive strategies and distinct architectures, spanning bipolar and tetrapolar systems with either linked or unlinked MAT loci. Building on recent comparative genomic analyses, we generated additional chromosome-level assemblies, uncovering distinct trajectories shaping MAT loci organization. Contrasting with the small-scale expansions and gene acquisitions observed in Kwoniella, our analyses revealed independent expansions of the P/R locus in tetrapolar Cryptococcus, possibly driven by pheromone gene duplications. Notably, these expansions coincided with a pronounced GC-content reduction best explained by reduced GC-biased gene conversion following recombination suppression, rather than relaxed codon usage selection. Diverse modes of MAT locus linkage were also identified, including three previously unrecognized transitions: one resulting in a pseudobipolar arrangement and two leading to bipolarity. All three transitions involved translocations. In the pseudobipolar configuration, the P/R and HD loci remained on the same chromosome but genetically unlinked, whereas the bipolar transitions additionally featured rearrangements that fused the two loci into a nonrecombining region. Mating assays confirmed a sexual cycle in C. decagattii, demonstrating its ability to undergo mating and sporulation. Progeny analysis in K. mangrovensis revealed substantial ploidy variation and aneuploidy, likely stemming from haploid-diploid mating, yet evidence of recombination and loss of heterozygosity indicates that meiotic exchange occurs despite irregular chromosome segregation. Our findings underscore the importance of continued diversity sampling and provide further evidence for convergent evolution of fused MAT loci in basidiomycetes, offering new insights into the genetic and chromosomal changes driving reproductive transitions.

MAT genes