Search Results (254)

Background: Copy number variants of uncertain significance (CNVus) from chromosome microarray analysis (CMA) presents unresolved challenges for clinical geneticists, genetic counselors, and patients. We performed a systematic reevaluation of reported CNVus and reanalysis of selected CNVus by whole genome sequencing (WGS) to assess the diagnostic value and clinical impact on CNVus reclassification. Methods: We retrospectively reviewed 5277 consecutive pediatric cases by CMA from the Yale Clinical Cytogenetics Laboratory over a 13-year period. Reevaluation was performed on all reported CNVus following current ACMG/ClinGen guidelines. Reanalysis by WGS was applied to selected cases for reclassification of CNVus. Results: A total of 567 CNVus from 480 cases were reported, which accounted for 9.1% of pediatric cases. A total of 4 CNVus in 4 cases (0.8%, 4/480) were reclassified to pathogenic/likely pathogenic CNVs (pCNVs/lpCNVs); while 23 CNVus in 23 cases (4.8%, 23/480) were reclassified to benign/likely benign CNVs (bCNVs/lbCNVs). The overall rate of reclassification was 5.6%. WGS performed on selected cases further defined breakpoints and ruled out additional causative genetic variants. Conclusions: The results from this study demonstrated the diagnostic value of periodic reevaluation of CNVus and reanalysis by WGS in an interval of 3–5 years and provided evidence to support standardized laboratory reevaluation and reanalysis. Full article

Background: Neurodevelopmental disorders (NDDs), including autism spectrum disorder (ASD), are genetically complex and often linked to structural genomic variations such as copy number variants (CNVs). Current diagnostic strategies face challenges in interpreting the clinical significance of such variants. Methods: We developed a customized, gene-oriented chromosomal microarray (CMA) targeting 6026 genes relevant to neurodevelopment, aiming to improve diagnostic yield and candidate gene prioritization. A total of 39 patients with unexplained developmental delay, intellectual disability, and/or ASD were analyzed using this custom platform. Systems biology approaches were employed for downstream interpretation, including protein–protein interaction networks, centrality measures, and tissue-specific functional module analysis. Results: Pathogenic or likely pathogenic CNVs were identified in 31% of cases (9/29). Network analyses revealed candidate genes with key topological properties, including central “hubs” (e.g., NPEPPS, PSMG1, DOCK8) and regulatory “bottlenecks” (e.g., SLC15A4, GLT1D1, TMEM132C). Tissue- and cell-type-specific network modeling demonstrated widespread gene involvement in both prenatal and postnatal developmental modules, with glial and astrocytic networks showing notable enrichment. Several novel CNV regions with high pathogenic potential were identified and linked to neurodevelopmental phenotypes in individual patient cases. Conclusions: Customized CMA offers enhanced detection of clinically relevant CNVs and provides a framework for prioritizing novel candidate genes based on biological network integration. This approach improves diagnostic accuracy in NDDs and identifies new targets for future functional and translational studies, highlighting the importance of glial involvement and immune-related pathways in neurodevelopmental pathology. Full article

Brain morphological abnormalities are common in patients with neurodevelopmental disorders (NDDs) and other neuropsychiatric disorders, often reflecting abnormal brain development and function. Genetic studies have found common genetic factors in NDDs and other neuropsychiatric disorders, although the etiology of brain structural changes in these disorders remains poorly understood. In this study, we analyzed magnetic resonance imaging (MRI) and genetic data from more than 30K individuals from the UK Biobank to evaluate whether NDD-risk copy number variants (CNVs) are also associated with neuroanatomical changes in both patients and neurotypical individuals. We found that the size differences in brain regions such as corpus callosum and cerebellum were associated with the deletions of specific areas of the human genome, and that specific neuroanatomical changes confer a risk of neuropsychiatric disorders. Furthermore, we observed that gene sets located in these genomic regions were enriched for pathways crucial for brain development and for phenotypes commonly observed in patients with NDDs. These findings highlight the link between CNVs, brain structure abnormalities, and the shared pathophysiology of NDDs and other neuropsychiatric disorders, providing new insights into the underlying mechanisms of these disorders and the identification of potential biomarkers for better diagnosis. Full article

BRCA1 and BRCA2 are associated with advanced prostate cancer progression and poor prognosis. Copy number variants (CNVs) of these genes play a crucial role in guiding targeted treatments, particularly for patients receiving PARP inhibitors. However, CNV detection using multiplex ligation-dependent probe amplification (MLPA) is often limited by tumor heterogeneity, leading to ambiguous results. This study therefore aimed to evaluate BRCA1/2 CNVs in advanced prostate cancer patients using droplet digital PCR (ddPCR) and compare the results with MLPA. DNA from 11 advanced prostate cancer tissues was analyzed using both methods, in parallel with four cell lines and seven healthy volunteers. Our findings revealed that ddPCR effectively classified normal CNV groups—including normal control cell lines, healthy volunteers, and samples with normal MLPA final ratios—from deletion groups, which included deletion control cell lines, samples with deletion final ratios from MLPA, and cases with previously ambiguous results. Interestingly, two cases involving BRCA1 and one case involving BRCA2 exhibited ambiguous results using MLPA; however, ddPCR enabled more precise classification by applying the Youden Index from ROC analysis and identifying optimal cutoff values of 1.35 for BRCA1 and 1.55 for BRCA2. These optimal thresholds allowed ddPCR to effectively reclassify the ambiguous MLPA cases into the deletion group. Overall, ddPCR could offer a more sensitive and reliable approach for CNV detection in heterogeneous tissue samples and demonstrates strong potential as a biomarker tool for guiding targeted therapy in advanced prostate cancer patients. However, further validation in larger cohorts is necessary to optimize cutoff precision, confirm diagnostic performance, and evaluate the full clinical utility of ddPCR. Full article

Sudden cardiac death represents an unexpected death for which a strong underlying genetic background has been described. The primary causes are identified in cardiomyopathies and channelopathies, which are heart diseases of the muscle and electrical system, respectively, without coronary artery disease, hypertension, valvular disease, and congenital heart malformations. Genetic variants, especially single nucleotide variants and short insertions/deletions impacting essential myocardial functions, have shown that cardiomyopathies display high heritability. However, genetic heterogeneity, incomplete penetrance, and variable expression may complicate the interpretation of genetic findings, thus delaying the management of seriously at-risk patients. Moreover, recent studies show that the diagnostic yield related to genetic cardiomyopathies ranges from 28 to 40%, raising the need for further research. In this regard, investigating the occurrence of structural variants, especially copy number variants, may be crucial. Based on these considerations, this review aims to provide an overview of copy number variants identified in cardiomyopathies and discuss them, considering diagnostic yield. This review will ultimately address the necessity of incorporating copy number variants into routine genetic testing for cardiomyopathies and channelopathies, a process increasingly enabled by advances in next-generation sequencing technologies. Full article

In the era of precision oncology, comprehensive molecular profiling is critical for guiding targeted and immunotherapy strategies. This study presents the analytical and clinical validation of a 1021-gene next-generation sequencing (NGS) panel, designed for use with both formalin-fixed paraffin-embedded (FFPE) tissue- and liquid-biopsy specimens. Analytical validation confirmed the assay’s high sensitivity and specificity across variant types—including SNVs (Single Nucleotide Variations), indels, CNVs (Copy Number Variations), and fusions—down to a 0.5% variant allele frequency. The assay also accurately identified microsatellite instability (MSI) and tumor mutational burden (TMB), essential biomarkers for immunotherapy. Clinical validation was performed on over 1300 solid tumor samples from diverse histologies, revealing actionable alterations in over 50% of cases. The panel detected on-label treatment biomarkers in 12.57% of patients, increasing to 20.15% when immunotherapy markers were included. Additionally, the assay demonstrated strong concordance with orthogonal methods and was effective in detecting variants in plasma-derived circulating tumor DNA in 70% of evaluable cases. These findings support the robust performance and broad clinical applicability of the 1021-gene panel for comprehensive genomic profiling in both tissue and liquid biopsies, offering a valuable tool for personalized cancer treatment. Full article

Background: Next-generation sequencing (NGS), particularly whole-exome sequencing (WES), has become a powerful diagnostic tool for rare genetic conditions. However, its success rate varies based on the underlying genetic etiology and the population studied. Methods: This retrospective study evaluated the diagnostic yield of NGS in a cohort of 137 pediatric patients with suspected rare genetic disorders in Bulgaria, a setting where such testing is not reimbursed and must be self-funded. The patients underwent either WES or targeted gene panel testing based on clinical presentation, family history, and genetic evaluation. Results: The overall diagnostic yield was 45.99%, with WES achieving 51.25% and targeted testing achieving 38.60%. The highest yield was observed in patients presenting with both dysmorphic features and neurodevelopmental delays (62.5%), while the lowest was observed among those with isolated neurodevelopmental issues (10%). A significant portion of the identified variants (35.9%) were novel. Eight patients were diagnosed with copy number variants (CNVs) detected only through WES. Conclusions: Our findings illustrate the value of WES as a first-line test and highlight the impact of deep phenotyping on diagnostic success. This study also emphasizes the need for a population-specific reference genome and equal access to genomic diagnostics in all European countries. Full article

Background: Circulating cell-free DNA (cfDNA) has been widely used as a prognostic marker for different cancers. Objective: In this study, we used 30 cfDNA samples from oral squamous cell carcinoma (OSCC), 199 public OSCC samples, and 192 normal samples to study various correlation factors that could improve the early-stage diagnostics and/or prognosis of OSCC. Methods: The statistical correlation between healthy and OSCC patients was done and deep sequencing analyses was performed to study various genomic alterations likes copy number variation (CNV), and single nucleotide variants (SNVs), gene fusion and genomic integration of viruses. Results: We found that the OSCC patient cfDNA concentration can serve as an indicator of tumor stage, malignancy, and survival prognosis. Deep genome sequencing of cfDNA revealed genomic alterations, such as CNVs, fusion genes, and viral integrations. The CNV analysis suggested a correlation with amplification and deletion in chromosomes at loci 1q, 2q, 3p, 3q, and chromosome 8 at loci q22. Moreover, at these loci, amplification of TP53, PIK3CA, and other genes related to keratinization in OSCC patients was observed. In addition, we identified a novel abundant fusion gene, TRMO-TRNT1 ‘chimera’, in seven high-grade tumor samples. The parental genes of this chimera, TRMO and TRNT1, are known to play roles in tRNA modification and DNA repair, respectively. We have identified SNVs in our OSCC cohort. Some of these SNVs, like KMT2C, MUC3A, and MUC6, have been identified as common cases in different cancer populations. Finally, we detected contigs integrations of human papillomavirus, simian virus, and enterovirus in the OSCC samples, which may point to the potential causes of OSCC. Conclusions: Our results indicate that the liquid biopsy technique may thus serve as a sensitive tool to study OSCC patient genomic alterations by exploring cfDNA circulating in the plasma, providing an easy-to-use blood test in the future. Full article

Copy number variations (CNVs), as an important structural variant in genomes, are widely present in plants, affecting their phenotype and adaptability. In recent years, CNV research has not only focused on changes in gene copy numbers but has also been linked to complex mechanisms such as genome rearrangements, transposon activity, and environmental adaptation. The advancement in sequencing technologies has made the detection and analysis of CNVs more efficient, not only revealing their crucial roles in plant disease resistance, adaptability, and growth development, but also demonstrating broad application potential in crop improvement, particularly in selective breeding and genomic selection. By studying CNV changes during the domestication process, researchers have gradually recognized the important role of CNVs in plant domestication and evolution. This article reviews the formation mechanisms of CNVs in plants, methods for their detection, their relationship with plant traits, and their applications in crop improvement. It emphasizes future research directions involving the integration of multi-omics to provide new perspectives on the structure and function of plant genomes. Full article

Super-enhancers (SEs) orchestrate high-level transcription by integrating multiple regulatory elements and signals. Although chromatin accessibility and transcription factor binding within SEs are extensively studied, the role of non-canonical DNA structures, particularly Z-DNA, remains underexplored. In this study, genome-wide predictions of Z-DNA-forming sequences (generated by the Z-DNA-BERT model) were applied to systematically investigate their distribution within typical enhancers and SEs across multiple human cancer cell lines. Statistically significant enrichment of Z-DNA sequences within SE regions, compared to random genomic controls, was observed. Furthermore, genetic variants overlapping these Z-DNA regions, identified using data from the 1000 Genomes Project, were found to alter binding motifs of the SP/KLF transcription factor family. These mutations exhibited population-specific clustering and overlapped previously reported pathogenic copy-number variations (CNVs) associated with neurodevelopmental disorders, potentially affecting transcription factor binding motifs related to neuronal growth and differentiation pathways. Population-level phylogenetic analysis revealed distinct clustering patterns of these variants, suggesting frequency-specific genetic architecture. Overall, the computational findings indicate that Z-DNA structures within super-enhancers might play regulatory roles and potentially influence population-specific genetic variation, highlighting specific genomic targets and providing new avenues for future experimental research. Full article

Background/Objectives: Compared to single gene testing (SGT), multigene panel testing (MGPT) improves pathogenic variants (PVs) detection. However, MGPT yields complex results, including secondary findings, heterozygous PVs in recessive genes, low-penetrance PVs, and variants of uncertain significance. We reported our mono-institutional experience of germline testing in breast cancer (BC), comparing SGT and MGPT. Methods: We retrospectively analyzed clinical and molecular data from 1084 BC patients: 308 underwent SGT (BRCA1/BRCA2) and 776 MGPT (for 28 cancer-related genes). We compared these approaches regarding the genetic classification of the findings (positive, uncertain, uninformative) and their impact on clinical management (primary findings (PFs); complex and inconclusive results). Additionally, we described clinical features supporting one approach over the other and focused on copy number variation (CNV) frequency in non-BRCA genes. Results: We found ≥1 PV in 165 patients (165/1084 = 15.2%), including 91 in BRCA1/BRCA2 (91/1084 = 8.4%), with 42 identified by SGT (42/308 = 13.6%) and 49 by MGPT (49/776 = 6.3%). MGPT detected PVs in non-BRCA genes in 74 patients (74/776 = 9.5%), including 40 PFs. Overall, MGPT identified 89 PFs (89/776 = 11.5%). We observed complex results in 21 patients (21/308 = 6.8%) with SGT and in 300 (300/776 = 38.7%) with MGPT. Compared to MGPT, SGT detected a similar percentage of PFs (13.6% vs. 11.5%) but a significantly reduced percentage of complex results (6.8% vs. 38.7%) (p < 0.001). Triple-negative BCs prevailed in BRCA1 carriers, while ER-positive BCs were more prevalent in ATM/CHEK2 carriers. Concerning non-BRCA genes, MGPT detected CNVs in PALB2, representing 20% of PVs in this gene. Conclusions: Although MGPT increases hereditary BC detection, its complexity requires clear guidelines for optimal clinical management and strategies for merging the benefits of SGT and MGPT. Full article

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that first develops in early childhood and is characterized by restricted interests, activities, and behaviors, as well as difficulties with social interactions and communication. ASD arises from a complex interaction between environmental factors and genetic inheritance, influenced by epigenetic mechanisms. With an estimated heritability of 70–90%, ASD is highly familial, indicating that genetic factors play a significant role in its development. This shows how hundreds of genetic variants contribute to ASD, whose risk effects are highly variable and are often related to other conditions; these genetic alterations are at different levels, which include single gene mutations, monogenic disorders, genomic variants, and chromosomal abnormalities. Copy number variants (CNVs) appear to contribute significantly to understanding the pathogenesis of this complex disease. In some cases, single CNVs in genomic DNA are pathogenic and causative, supporting the hypothesis that some sporadic cases of ASD may result from rare mutations with significant clinical impact. However, in many cases, there are common genomic variants that increase the risk of developing ASD but are insufficient by themselves to determine an ASD phenotype, and rare genomic variants, of various sizes, inherited from a parent or de novo, that can be associated with the ASD phenotype. Therefore, the aim of this review is to deepen the concept of ASD inheritance through the two-hit theory of CNVs, in which the concomitant presence of two alterations could determine the clinical phenotypes, the concept of incomplete penetrance for inherited CNVs with pathogenic clinical significance, and the presence of compound heterozygosity. These aspects represent important mechanisms underlying the pathogenesis of autism, contributing to a better elucidation for the understanding of the genetic contribution to the ASD phenotype. Full article

Schizophrenia (SCZ) is a complex mental disorder, whose pathogenesis involves both environmental and genetic factors. Genetic risk is conferred through a combination of common variants and rare mutations, with point mutations and copy number variants (CNVs). Many of the genetic variants associated with SCZ have pleiotropic effects, influencing brain development and being shared with other neurodevelopmental disorders (NDDs), such as intellectual disability (ID). This overlap supports the concept of a neurodevelopmental continuum, suggesting shared genetic risk, at least between SCZ and ID, and most presumably among SCZ and many other NDDs. Here, we describe the case of a male patient whose clinical features align with this hypothesis. He presented cognitive and behavioral impairments preceding psychotic symptoms, further reinforcing the genetic and clinical interaction between SCZ and other NDDs. The patient’s genetic profile was analyzed using array comparative genomic hybridization (a-CGH) and whole-exome sequencing (WES) to investigate the genetic determinants underlying his clinical condition. The genetic testing identified variants in loci associated with both SCZ and NDDs. Our findings highlight the need to integrate genetic assessments into psychiatrists’ clinical practice. Moreover, this report contributes to the current body of evidence supporting the thesis on the neurodevelopmental continuum of SCZ. Full article

We introduce an innovative, non-invasive prenatal screening approach for detecting fetal monogenic alterations and copy number variations (CNVs) from maternal blood. Method: Circulating free DNA (cfDNA) was extracted from maternal peripheral blood and processed using the VeriSeq NIPT Solution (Illumina, San Diego, CA, USA), with shallow whole-genome sequencing (sWGS) performed on a NextSeq550Dx (Illumina). A customized gene panel and bioinformatics tool, named the “VERA Revolution”, were developed to detect variants and CNVs in cfDNA samples. Results were compared with genomic DNA (gDNA) extracted from fetal samples, including amniotic fluid and chorionic villus sampling and buccal swabs. Results: The study included pregnant women with gestational ages from 10 + 3 to 15 + 2 weeks (mean: 12.1 weeks). The fetal fraction (FF), a crucial measure of cfDNA test reliability, ranged from 5% to 20%, ensuring adequate DNA amount for analysis. Among 36 families tested, 14 showed a wild-type genotype. Identified variants included two deletions (22q11.2, and 4p16.3), two duplications (16p13 and 5p15), and eighteen single-nucleotide variants (one in CFTR, three in GJB2, three in PAH, one in RIT1, one in DHCR7, one in TCOF1, one in ABCA4, one in MYBPC3, one in MCCC2, two in GBA1 and three in PTPN11). Significant concordance was found between our panel results and prenatal/postnatal genetic profiles. Conclusions: The “VERA Revolution” test highlights advancements in prenatal genomic screening, offering potential improvements in prenatal care. Full article

This study investigated the genetic causes of atypical cerebral palsy (CP) through chromosomal microarray (CMA) and exome sequencing (ES) in a cohort of 10 Korean patients to identify variants and expand the spectrum of mutations associated with atypical cerebral palsy. Whole ES and/or genome sequencing (GS) after routine karyotyping and CMA was performed to identify causative variants and expand the spectrum of mutations associated with atypical CP. In cases of atypical CP, scoliosis and/or kyphosis, ranging from mild to severe, were present in all patients. Epilepsy was a comorbidity in seven patients (70%), and intellectual disability (ID) was observed in varying degrees. This study identified three copy number variations (CNVs), including 15q11.2 microdeletion (n = 1), 17p11.2 duplication (n = 1), and 12p13.33p11.23 duplication/18p11.32 microdeletion (n = 1), and six likely pathogenic variants (LPVs) or pathogenic variants (PVs) detected in the SLC2A1, PLAA, CDC42BPB, CACNA1D, ALG12, and SACS genes (n = 6). These findings emphasize the significance of incorporating genetic testing into the diagnostic process for atypical CP to improve our understanding of its molecular basis and inform personalized treatment strategies. To further advance this research, future studies should focus on exploring genotype–phenotype correlations, assessing the functional impact of identified variants, and increasing the sample size to validate the observed patterns. Full article