Search Results (405)

Background/Objectives: Short-read-sequencing (SRS) is currently the standard for genetic testing in inherited human diseases. Intrinsic limitations include PCR dependency, restricted read length, and challenges in identifying structural variants (SVs), copy number variations (CNVs), and intronic small variants (SNVs/indels). Long-read-sequencing (LRS) enables the sequencing of long DNA molecules, detection of deep intronic variants, rapid testing of few samples, and improved resolution of SVs, CNVs, and SNVs/indels. We therefore aimed to validate Oxford Nanopore Technologies (ONT) LRS for potential clinical application. Methods: We evaluated the ONT’s ability to detect pathogenic/likely pathogenic (P/LP) variants previously identified by SRS and confirmed via Sanger sequencing, Multiplex-Ligation-dependent-Probe-Amplification (MLPA), or quantitative-PCR (qPCR). In total, 509 samples were analyzed, including 393 with P/LP variants and 116 negative controls. We used CE-IVD panels HEVA pro, CARDIO pro, BRaCA panel, and ClinEX pro (4Bases-CH). Sequencing was performed on MinION, GridION, and PromethION-2 platforms. Data were analyzed using the 4eVAR pipeline. Results: ONT successfully identified all P/LP variants across the panels (sensitivity 100%); identified a previously missed CNV in ENG gene; precisely defined the breakpoints of a del(13q) (unsuspected and diagnosed as BRCA2 del ex2–14); improved the coverage profiles in difficult-to-map regions (e.g., ex1 TGFBR1, PSM2CL); expanded the coverage of out-of-target deep intronic regions; and allowed for the set-up of fast-track tests (<24 h) for urgent clinical needs. Conclusions: Our findings demonstrate that ONT LRS provides diagnostic performance comparable to SRS, with significant advantages in resolving complex and previously undetectable variants. Ongoing developments are further increasing read length, expanding detectable targets, and potential clinical applications. Full article

Copy number variations (CNVs) affecting the chromosomal region 21q21.3–q22.13 are rare and have been increasingly associated with neurodevelopmental abnormalities and multisystemic manifestations. In this study, we aimed to characterize the clinical, genomic, and genotype–phenotype correlations of a Moroccan child carrying a de novo microdeletion in this region. Whole exome sequencing (WES) was performed using sequencing-by-synthesis technology on the GenoLab M platform, and CNV detection was achieved through the SeqOne platform. Variant interpretation was conducted using the Integrative Genomics Viewer (IGV), and a custom gene–phenotype heatmap was generated in R (ComplexHeatmap and pheatmap) based on OMIM, ClinVar, and DECIPHER databases to prioritize candidate genes within the deleted segment. The patient presented with global developmental delay, microcephaly, psychomotor and staturo-ponderal retardation, facial dysmorphism, epilepsy responsive to treatment, and cerebral anomalies, including passive biventricular hydrocephalus and diffuse cortical atrophy. WES-CNV analysis identified a heterozygous de novo microdeletion of approximately 8.2 Mb in 21q21.3–q22.13, encompassing 124 clinically relevant genes. Integrated analysis confirmed the pathogenicity of the deletion and highlighted genotype–phenotype correlations, particularly implicating dosage-sensitive genes such as SON and RUNX1. This case underlines the clinical utility of combining WES, CNV analysis, and phenotype-based bioinformatic tools for diagnosing complex microdeletion syndromes, contributes to understanding genotype–phenotype relationships in 21q21.3–q22.13 deletions, and supports improved clinical interpretation and patient management. Full article

Background: Acute lymphoblastic leukemia (ALL) is a genetically heterogeneous malignancy driven by structural variants (SVs) that impact diagnosis, prognosis, and treatment. Traditional methods such as karyotyping, FISH, and PCR often fail to detect cryptic or complex rearrangements, which are critical for accurate risk stratification. Methods: Optical Genome Mapping (OGM) is a technology that directly analyzes ultra-high-molecular-weight DNA, enabling the identification of balanced and unbalanced SVs, copy number variations (CNVs), and gene fusions with high resolution. This review compares the advantages and limitations of OGM versus standard techniques in ALL. Results: OGM improves ALL diagnosis by detecting clinically relevant alterations such as IKZF1 deletions, cryptic KMT2A rearrangements, and kinase fusions, especially in cases with normal or uninformative karyotypes. It reduces artifacts by eliminating cell culture and shortens reporting times. OGM resolves complex events like intrachromosomal amplifications and chromothripsis, enhancing classification and therapy decisions. Limitations include reduced sensitivity in repetitive regions, challenges in detecting Robertsonian translocations, difficulties with complex ploidies, and lower sensitivity for low-frequency subclones. Conclusions: Integrating OGM with next-generation sequencing (NGS) allows comprehensive genomic profiling, improving diagnosis, prognosis, and personalized treatment in ALL. Future advancements promise to further enhance the clinical utility of OGM. Full article

Background: Wilson’s disease (WD) is a rare autosomal recessive disorder caused by mutations in the ATP7B gene, leading to copper accumulation in the liver and brain. Given the clinical heterogeneity of the disease, this study aimed to characterize the mutational spectrum of ATP7B and explore genotype–phenotype correlations in Turkish patients. Methods: Whole-exome sequencing (WES) was performed in 17 Turkish patients clinically diagnosed with WD. Variants were annotated and evaluated using five in silico prediction tools (REVEL, CADD, PolyPhen, SIFT, MutationTaster). Copy number variation (CNV) analysis was conducted using the CLC Genomics Server (Version 22.0.2). Results: A total of 14 distinct ATP7B variants were identified, comprising 12 missense, 1 nonsense, and 1 frameshift mutation. Variant distribution showed some phenotype-specific patterns: four variants were found more frequently in hepatic cases and three in neurological cases, although no statistically significant or consistent correlation between genotype and clinical presentation could be established. The most frequent mutation was p.His1069Gln, present in both phenotypes. All missense variants were predicted to be pathogenic by at least three computational tools, with high concordance among platforms. No pathogenic CNVs were detected. Conclusions: This study expands the mutational landscape of ATP7B in Turkish patients with WD and supports the utility of WES combined with in silico tools for accurate variant classification. The results emphasize the genetic heterogeneity of WD and suggest possible associations between certain mutations and clinical phenotypes. Full article

Deciphering egg laying-related genetic basis and aggregating its key genes or genetic markers will be helpful for genetic improvement of chicken laying-oriented breeding. Our previous research found adaptor related protein complex 2 mu 1 subunit (AP2M1) gene is a key candidate gene related to egg production. However, its functions and genetic regulatory mechanisms remain unclear. This study aims to clarify AP2M1 functions and identify its functional variants. Expression characteristic analysis of AP2M1 within and between breeds confirmed the negative regulatory relationship of hypothalamic AP2M1 expression on egg production. Overexpression and interference tests indicated that AP2M1 inhibited GnRH synthesis and secretion in chicken hypothalamic neuron cells. To explore molecular markers influencing AP2M1 expression, a copy number variation (CNV) region containing AP2M1 were verified in different chicken breeds by qRT-PCR; a copy number loss of AP2M1 were observed in layers compared to native breeds, commercial broilers, and wild breed. Correlation analysis between CNV and egg number, as well as differential expression analysis of different copy numbers, indicated that the CNV contributed to the differences in egg production by influencing AP2M1 expression. Meanwhile, through association analysis of whole-genome SNPs in AP2M1 with 13 egg production traits, 15 egg-laying related SNPs were identified. Further difference expression analysis among the different genotypes of SNPs and dual-luciferase reporter assay confirmed that chr9:15994879T>C was a functional SNP regulating AP2M1 expression. These findings unveil egg laying-related functional molecular markers will help accelerate molecular design breeding process of chicken egg production. Full article

Precision medicine approaches rely on accurate somatic variant detection, where the DNA input into genomic workflows is a key variable. However, there are no gold standard methods for total DNA quantification. In this study, a pentaplex reference gene panel using digital PCR (dPCR) was developed as a candidate reference method. The multiplex approach was compared between two assay chemistries, applied to healthy donor genomic DNA and plasma cell-free DNA (cfDNA) to measure the ERBB2 (HER2) copy number variation in cancer cell line DNA. The multiplex approach demonstrated robust performance with the two assay chemistries, demonstrating comparable results and a wide dynamic range. Ratios of reference genes were close to the expected 1:1 in healthy samples; however, some small but significant differences (<1.2-fold) were observed in one of the five targets. Expanded relative measurement uncertainty was 12.1–19.8% for healthy gDNA and 9.2–25.2% for cfDNA. The multiplex approach afforded lower measurement uncertainty compared to the use of a single reference for total DNA quantification, which is an advantage for its potential use as a calibration method. It avoided potential biases in the application to CNV quantification of cancer samples, where cancer genome instability may be prominent. Full article

Immunogenic cell death (ICD) is a specialized form of cell death that triggers antitumor immune responses. In tumors, ICD promotes the release of tumor-associated and tumor-specific antigens, thereby reshaping the immune microenvironment, restoring antitumor immunity, and facilitating tumor eradication. However, the regulatory mechanisms of ICD and its immunological effects vary across tumor types, and a comprehensive understanding remains limited. We systematically analyzed the expression of 34 ICD-related regulatory genes across 33 tumor types. Differential expression at the RNA, copy number variation (CNV), and DNA methylation levels was assessed in relation to clinical features. Associations between patient survival and RNA expression, CNVs, single-nucleotide variations (SNVs), and methylation were evaluated. Patients were stratified into immunological subtypes and further divided into high- and low-risk groups based on optimal prognostic models built using a machine learning framework. We explored the relationships between ICD-related genes and immune cell infiltration, stemness, heterogeneity, immune scores, immune checkpoint and regulatory genes, and subtype-specific expression patterns. Moreover, we examined the influence of immunotherapy and anticancer immune responses, applied three machine learning algorithms to identify prognostic biomarkers, and performed drug prediction and molecular docking analyses to nominate therapeutic targets. ICD-related genes were predominantly overexpressed in ESCA, GBM, KIRC, LGG, PAAD, and STAD. RNA expression of most ICD-related genes was associated with poor prognosis, while DNA methylation of these genes showed significant survival correlations in LGG and UVM. Prognostic models were successfully established for 18 cancer types, revealing intrinsic immune regulatory mechanisms of ICD-related genes. Machine learning identified several key prognostic biomarkers across cancers, among which NT5E emerged as a predictive biomarker in head and neck squamous cell carcinoma (HNSC), mediating tumor–immune interactions through multiple ligand–receptor pairs. This study provides a comprehensive view of ICD-related genes across cancers, identifies NT5E as a potential biomarker in HNSC, and highlights novel targets for predicting immunotherapy response and improving clinical outcomes in cancer patients. Full article

Fanconi anemia (FA) is a genetic disorder characterized by congenital anomalies, bone marrow failure, and cancer predisposition. Among other solid cancers, head and neck squamous cell carcinoma (FA HNSCC) is the most common cancer type in individuals with FA. The FA pathway is required for the complete repair of DNA interstrand crosslinks (ICLs), and unresolved ICLs result in cell cycle arrest, apoptosis, or complex chromosomal rearrangements due to chromosome breaks, ultimately leading to tumorigenesis. FA HNSCCs present earlier (median age of onset in the 30s) and exhibit a more aggressive course with frequent recurrence and second primaries, and entail a poorer survival rate compared to sporadic HNSCC. FA HNSCCs are mostly human papillomavirus (HPV)-negative and frequently carry somatic copy number variations (CNVs), which amplify oncogenes implicated in sporadic HNSCC, but single-nucleotide variants or small insertions and deletions are less frequent than in HPV-negative sporadic HNSCC. A subset of sporadic HNSCC carries pathogenic mutations or promoter methylation in FA genes, which also harbor characteristic somatic CNVs, suggesting shared molecular underpinnings with FA HNSCC. Heightened inflammation from genomic instability and transcriptional activation of retrotransposons contribute to tumorigenesis and increased invasiveness by the epithelial-to-mesenchymal transition. Due to heightened sensitivity to DNA crosslinking agents in patients with FA, platinum-based chemotherapy is generally avoided, which presents a significant hurdle for treatment and thereby leaves limited therapeutic options. Surgical management is the mainstay of therapy if possible, and targeted therapy has been increasingly studied in HNSCC in FA. Full article

The prevalence of childhood obesity has risen significantly, with numerous associated health risks. Emerging research suggests a potential role for genetic factors; particularly, copy number variations (CNVs) of the amylase 1 gene (AMY1) may influence obesity through dietary behavior and metabolic regulation. This study aimed to examine the relationship between BMI z-score, dietary intake, and salivary AMY1 gene copy number (CN) in children with overweight and obesity, and to assess the relationship between AMY1 CN and the impact of lifestyle intervention on these parameters. The study included 90 children aged 2–6 years with overweight or obesity. Participants were randomized into either a parent support intervention group or a standard care control group. Anthropometric measurements, dietary intake, and salivary AMY1 gene copy number were assessed at baseline and after a 9-month intervention. Positive correlations were found between AMY1 gene copy number, BMI z-score, and carbohydrate intake, suggesting a potential role of this gene in dietary behavior-related obesity. The parent support intervention led to significant reductions in children’s BMI, BMI z-score, and energy and macronutrient intake compared to standard care. Although there was no direct association between AMY1 copy number and changes in BMI z-score, higher AMY1 copy numbers were associated with greater reductions in polyunsaturated fatty acid intake. These findings highlight an interaction between salivary AMY1 gene copy number, dietary intake, and obesity in children. These results support the relevance of genetic factors in obesity-related dietary patterns and emphasize the effectiveness of targeted family-based lifestyle interventions. Full article

Glioblastoma (GB) is one of the most aggressive brain tumors, characterized by high infiltrative capacity that enables tumor cells to invade healthy brain tissue and evade complete surgical resection. This invasiveness contributes to resistance against conventional therapies and a high recurrence rate. Strategies capable of eliminating residual tumor cells are urgently needed. Photodynamic therapy (PDT) using 5-aminolevulinic acid (5-ALA), an FDA- and EMA-approved compound, induces selective accumulation of the photosensitizer protoporphyrin IX (PpIX) in metabolically active tumor cells, enabling targeted cytotoxicity through light activation. A major limitation to its clinical application is the unclear variation in the cytotoxic effect of PDT according to individual tumoral differences. In this study, we propose and validate an in vivo model of patient-derived GB initiating cells (GICs) and brain organoids to test the effects of PDT. First, patient-derived GICs were molecularly characterized by flow cytometry and copy number variation profiling using OncoScan CNV Assays, then co-cultured with human brain organoids to generate a hybrid model recapitulating key aspects of the tumor microenvironment. 5-ALA photodynamic therapy (PDT) efficacy was assessed in vitro by GFP-based viability measurements, LDH release assays, and TUNEL staining. Then, a murine model was generated to study PDT in vivo, based on a heterotopic (renal subcapsular engraftment) xenograft of the GICs-human brain organoid co-culture. PDT was tested in the model; in each subject, one kidney tumoral engraftment was treated and the contralateral served as a control. Immunofluorescence analysis was used to study the cell composition of the brain organoid-tumoral engraftment after PDT, and the effects on non-GIC cells. The antitumoral effect was determined by the degree of cell death analysis with the TUNEL technique. The GICs-brain organoid co-culture resulted in tumoral growth and infiltration both in vitro and in vivo. The pattern of growth and infiltration varied according to the tumoral genetic profile. 5-ALA PDT resulted in a reduction in the number of GICs and an increase in apoptotic cells in all four lines tested in vitro. A correlation was found between the induced phototoxicity in vivo with the molecular typification of GICs cell lines in vitro. There were no changes in the number or distribution of neuronal cells after the application of PDT, while a reduction in active astrocytes was observed. 5-ALA PDT could be effective in eradicating GICs with a heterogeneous molecular profile. The hybrid human-murine model presented here could be useful in investigating adjuvant therapies in GB, under the concept of personalized medicine. Full article

Background: Copy number variations (CNVs), also referred to as large genomic rearrangements (LGRs), represent a crucial component of BRCA1/2 (BRCA) testing. Next-generation sequencing (NGS) has become an established approach for detecting LGRs by combining sequencing data with dedicated bioinformatics pipelines. However, CNV detection in formalin-fixed paraffin-embedded (FFPE) samples remains technically challenging, and there is the need to implement a robust and optimized analysis strategy for routine clinical practice. Methods: This study evaluated 40 FFPE ovarian cancer (OC) samples from patients undergoing BRCA testing. The performance of the amplicon-based NGS Diatech Myriapod^® NGS BRCA1/2 panel (Diatech Pharmacogenetics, Jesi, Italy) was assessed for its ability to detect BRCA CNVs and results were compared to two hybrid capture-based reference assays. Results: Among the 40 analyzed samples (17 CNV-positive and 23 CNV-negative for BRCA genes), the Diatech pipeline showed a good concordance with the reference method—all CNVs were correctly identified in 16 cases with good enough sequencing quality. Only one result was inconclusive due to low sequencing quality. Conclusions: These findings support the clinical utility of NGS-based CNV analysis in FFPE samples when combined with appropriate bioinformatics tools. Integrating visual inspection of CNV plots with automated CNV calling improves the reliability of CNV detection and enhances the interpretation of results from tumor tissue. Accurate CNV detection directly from tumor tissue may reduce the need for additional germline testing, thus shortening turnaround times. Nevertheless, blood-based testing remains mandatory to determine whether detected BRCA CNVs are of hereditary or somatic origin, particularly in cases with a strong clinical suspicion of inherited predisposition due to young age and a personal and/or family history of OC. Full article

Copy number variation (CNV) is a common source of genomic structural variation by altering the number of DNA fragments, which in turn affects phenotypic variation and gene expression levels. However, there have been no reports of CNV in Chinese jujube (Ziziphus jujuba Mill.). In this study, we identified 16,570 CNVs from “Yuhong” × “Jiaocheng 5” and 140 hybrid progeny materials, of which 3607 CNVs were deletion type and 12,963 CNVs were duplication type. The distribution of CNVs in the Chinese jujube genome was systematically described, and the CNV genetic map of the whole genome level of the Chinese jujube hybrid offspring was constructed. Based on the field investigations, 13 individuals with severe black spot disease and no disease were analyzed for trait association. A total of 1837 CNVs were detected at the significant level of association, of which 1371 were duplication type and 466 were deletion type. And the GO (Gene Ontology) annotation item identified a systemic acquired resistance (SAR), and eight genes related to disease resistance were screened by the annotation. After validation by qPCR, these results further support the potential role in regulating black spot disease resistance. The constructed genome-wide CNV map of the hybrid progeny of Chinese jujube provides a new way of thinking for understanding the genetic basis of phenotypic variation of complex traits in Chinese jujube. Full article

TP53 genetic alterations represent a critical molecular feature in diffuse large B-cell lymphoma (DLBCL), with well-established associations with aggressive disease behavior and therapeutic resistance. However, significant controversy persists regarding the clinical utility of p53 immunohistochemical (IHC) expression as a surrogate marker. This study presents a thorough investigation of TP53 genetic alterations and their correlation with p53 protein expression in 664 cases of DLBCL. Using targeted next-generation sequencing (tNGS), we identified TP53 alterations (mutations and/or copy number losses (CNLs)) in 170 cases (25.6%). Among them, 161 cases had mutations. Concurrent analysis of copy number variations (CNVs) in 109 cases revealed TP53 CNLs in 17.4% (19/109), with 68.4% (13/19) of these showing coexisting mutations. Immunohistochemical evaluation of p53 expression in 371 cases demonstrated strong positivity (≥65% cells) in 21% (78/371), complete negativity (<1%) in 5.7% (21/371), and wild-type pattern (1–65%) in 73.3% (272/371) of cases. The p53 IHC laboratory-developed test (LDT) showed 79.2% sensitivity and 91.6% specificity for detecting TP53 alterations overall, though sensitivity varied significantly by mutation type: 86.2% for missense mutations but only 14.3% for nonsense mutations. Clinically, cases with TP53 alterations exhibited more aggressive disease characteristics, including higher ECOG performance scores, increased frequency of B symptoms, and poorer initial treatment responses (complete response rate 68.3% vs. 82.5% in wild-type cases). Most importantly, TP53 genetic alterations, but not p53 protein expression patterns, emerged as an independent prognostic factor for progression-free survival. Our findings demonstrate that tNGS effectively identifies most TP53 alterations and complementary CNV analysis enhances detection of copy number losses. The p53 IHC LDT serves as a useful but imperfect screening tool, with high specificity but variable sensitivity depending on mutation types. These results have important implications for molecular diagnostics in DLBCL, supporting the necessity for comprehensive genetic testing rather than reliance on protein expression analysis alone for accurate risk stratification and treatment planning. Full article

Background/Objectives: Attention Deficit Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder frequently associated with other neuropsychiatric conditions, characterized by high clinical heterogeneity and a complex genetic background. Recent studies suggest that copy number variations (CNVs) may contribute to ADHD susceptibility, particularly when involving genes related to brain development, attention regulation, and impulse control. This study investigated the association between CNVs and ADHD phenotype by identifying patients with and without potential pathogenic CNVs. Methods: We evaluated 152 well-characterized ADHD pediatric patients through comprehensive clinical assessments, including dysmorphic features, brain MRI, EEG patterns, and cognitive testing. CNVs were identified using array Comparative Genomic Hybridization (array-CGH). Participants were classified as carrying potentially causative CNVs (PC-CNVs), non-causative CNVs (NC-CNVs), or without CNVs (W-CNVs) and statistically compared across clinical and neurodevelopmental measures. Results: CNVs were identified in 81 participants (53%), comprising 13 with PC-CNVs (8.5%) and 68 with NC-CNVs (44.7%). ADHD symptoms were pronounced across all groups, but PC-CNVs showed a higher burden of comorbidities, suggesting a stronger genetic contribution to ADHD complexity. Significant differences were observed in oppositional behavior, inattentive symptoms, brain MRI findings, and developmental language anomalies. Several CNVs involved genes previously implicated in neurodevelopmental disorders, supporting a potential genetic contribution to the clinical complexity of ADHD. Conclusions: This exploratory study supports the role of CNVs in ADHD susceptibility and highlights the value of genetic screening for understanding clinical variability. Larger studies are needed to clarify genotype–phenotype correlations in ADHD and to guide personalized clinical management. Full article

Background/Objectives: Despite the increasing emergence of resistance, insecticide-based tools remain the primary method for malaria vector control in Africa. To maintain the effectiveness of these interventions, continuous monitoring and identification of novel resistance mechanisms is essential. This study aimed to investigate potential new insecticide resistance genes in the Anopheles gambiae complex. Methods: We analyzed whole-genome sequencing data from the An. gambiae 1000 Genomes Project. A broad range of genomic analysis techniques and tools were used to identify and explore genetic variation in the candidate resistance genes. Results: High haplotype homozygosity values, indicative of positive selection, were detected in a 2L chromosomal region corresponding to an aldehyde oxidase gene cluster (AGAP006220, AGAP006221, AGAP006224, AGAP006225, AGAP006226). Single nucleotide polymorphisms (SNPs) have been identified in these genes with frequencies up to 100%, including 569, 691, 1433, 978, and 811 non-synonymous SNPs in AGAP006220, AGAP006221, AGAP006224, AGAP006225, and AGAP006226, respectively. Copy number variations (CNVs) such as deletions and amplifications were also identified at low frequencies (<12%). Population structure analyses revealed adaptive and geographic gene flow between An. gambiae and An. coluzzii. Conclusions: This study provides evidence that aldehyde oxidase genes may contribute to insecticide resistance in An. gambiae s.l. populations. These results highlight the importance of genomic surveillance for detecting novel resistance loci and guiding the development of improved vector control strategies under changing ecological and evolutionary conditions. Full article