Search Results (320)

Autism spectrum disorder (ASD) and related neurodevelopmental disorders (NDDs) are characterized by a complex genetic architecture involving both rare high-impact variants and cumulative low-effect alterations. The contribution of borderline copy number variants (CNVs) to disease susceptibility and phenotypic variability remains incompletely understood. Reflecting a real-world clinical setting rather than a prospectively recruited research cohort, we performed a retrospective analysis of a tertiary care registry comprising 328 individuals referred for suspected ASD or NDDs who underwent array comparative genomic hybridization (a-CGH), identifying 612 CNVs classified according to ACMG/ClinGen guidelines. CNVs were evaluated by type, size, genomic distribution, and clinical correlation, and patients were stratified based on CNV burden and the presence of borderline variants. Duplications were more frequent than deletions, and medium-sized CNVs (100–500 kb) were the most common. Borderline CNVs represented the largest category. Within this descriptive cohort, increased CNV burden, in both number and cumulative genomic size, co-occurred more frequently in individuals with severe phenotypes, including ASD with intellectual disability, epilepsy, and broader NDDs. Individuals with isolated ASD showed a lower burden and enrichment of small borderline variants, which often co-occurred alongside CNVs. In contrast, severe phenotypes were frequently associated with single large pathogenic variants. Recurrent loci included 15q11.2–q13, 16p11.2, and 22q11.21. Overall, these exploratory observations from a real-world clinical registry illustrate how cumulative genomic burden and borderline CNVs co-occur across different neurodevelopmental presentations, providing descriptive context for future mechanistic studies. Full article

Soft tissue sarcomas (STSs) are a heterogeneous group of rare mesenchymal malignancies with overlapping morphological and immunohistochemical features, often making definitive diagnosis challenging. Recent advances in next-generation sequencing (NGS) have enabled the identification of recurrent molecular alterations that contribute to tumor classification, prognostic stratification, and precision oncology approaches. This retrospective study aimed to evaluate the diagnostic and clinical impact of molecular profiling in pediatric soft tissue sarcomas using the Oncomine Childhood Cancer Research Assay (OCCRA) panel. Fifty-five frozen tumor samples representing 24 distinct soft tissue sarcoma subtypes were obtained from the Pediatric Oncology Institute -IOP/GRAACC/UNIFESP Biobank (B-053). Molecular analysis was performed using NGS to identify gene fusions, single nucleotide variants (SNVs), copy number variations (CNVs), and insertions/deletions (InDels). Clinically relevant molecular alterations were identified in 70% (37/55) of cases, including 18 fusion transcripts, 13 SNVs, 8 CNVs, and 6 InDels. Recurrent and diagnostically relevant alterations included BCOR::CCNB3, ASPSCR1::TFE3, NFR1::BRAF, FUS::DDIT3, EML4::NTRK3, ETV6::NTRK3, CIC::DUX4, NAB2::STAT6 and SS18::SSX1/2 fusions, as well as amplifications involving PDGFRA, FGFR1, GLI1, CDK4, ERBB3, and KIT. Pathogenic variants affecting genes involved in tumor suppression and chromatin remodeling, including TP53, NF1, DICER1, SMARCA4, PTEN, and PIK3CA, were also detected. Importantly, molecular profiling had significant diagnostic impact in several histologically ambiguous tumors, enabling molecular reclassification and refinement of previously inconclusive or inaccurate pathological diagnoses. In multiple cases, NGS transformed descriptive histopathological interpretations into genetically defined sarcoma entities, including NTRK-rearranged spindle cell neoplasms, CIC-rearranged sarcomas, synovial sarcoma, low-grade fibromyxoid sarcoma, and clear cell sarcoma. Furthermore, the identification of actionable alterations highlighted potential opportunities for targeted therapies and precision medicine approaches. Our findings demonstrate that comprehensive molecular profiling significantly enhances diagnostic accuracy in pediatric soft tissue sarcomas, particularly in morphologically challenging cases. The integration of NGS into routine sarcoma diagnostics enables biologically informed tumor classification and supports personalized therapeutic strategies. Full article

Triple-negative breast cancer (TNBC) lacking androgen receptor (AR) expression defines quadruple-negative breast cancer (QNBC), which is characterized by younger age at diagnosis, high Ki-67 index, and high genomic instability, however a comprehensive description of the genomic characteristics remains poorly defined. A total of 54 TNBC cases were categorized as TNBC with 100% AR expression (TNBC AR-100%) or QNBC, TNBC with 0% AR expression (TNBC AR-0%). Clinical, molecular, and genomic parameters, specifically pathogenic/likely pathogenic (P/LP) variants in homologous recombination repair (HRR) and cancer-related pathways were measured and analyzed. The QNBC cohort exhibited a high homologous recombination deficiency (HRD) score and a greater overall incidence of copy number variants (CNVs). QNBC harbored a higher mutation rate in TP53 and MYC signaling pathway than TNBC AR-100% tumors. P/LP variants corresponding to the HRR, PI3K/AKT, and RTK/RAS pathways were exclusively identified in QNBC. These results suggest that, at both molecular and genomic levels, the two groups are distinct, holding QNBC tumors more aggressive characteristics, genomic instability, and particular impairments in HRR and cancer-related pathways. In terms of actionability, these differences could potentially be leveraged through different combinations of therapies. Full article

The neurexin1 gene (NRXN1) encodes a presynaptic adhesion molecule that plays a critical role in synapse formation, maintenance, and function. Copy-number variants (CNVs) affecting the NRXN1 locus, including submicroscopic deletions, represent rare variant acting as a predisposition for neurodevelopmental disorders, such as Pitt–Hopkins-like syndrome type 2 (MIM #614325) and susceptibility to schizophrenia (MIM #621407). Variations in NRXN1 gene are associated with marked clinical heterogeneity. We present a familial case involving two male siblings (aged 6 and 5 years) and their 28-year-old mother, all exhibiting variable neurodevelopmental phenotypes. Both children demonstrated disharmonic developmental profiles characterized by impaired communication, speech largely intelligible only to their parents, and behaviors consistent with autism spectrum disorder, including reduced eye contact. Mother represents a carrier with only subtle, nonspecific behavioral traits, further supporting the concept of incomplete penetrance and variable expressivity associated with this genetic alteration. Genetic analysis identified a 317 kb NRXN1 deletion shared by all affected family members, accompanied by significant intrafamilial phenotypic variability, suggesting the contribution of additional genetic and/or modifying factors. These findings support the concept that NRXN1 deletions alone do not determine clinical outcome but rather act within a broader genetic and biological context. The marked intrafamilial phenotypic variability and incomplete penetrance observed in this family is compatible with a multiple-hit model, whereby NRXN1 deletions act as susceptibility factors whose phenotypic consequences are shaped by additional genetic and modifying influences. However, the genetic mechanisms underlying the observed phenotypic variability warrant further investigation. Full article

Background: Comprehensive genomic profiling (CGP) via next-generation sequencing (NGS) is pivotal for precision oncology, yet many laboratories face challenges with incomplete genomic coverage, complex bioinformatics workflows, and limited integration of key biomarkers. Methods: We evaluated the analytical performance and clinical utility of a CGP assay using 119 tumor samples representing 18 types of cancer, previously analyzed with an orthogonal NGS panel. Concordance was assessed across 81 genes, covering 176 single-nucleotide variants (SNVs), eight copy number variations (CNVs), four deletions, one duplication, and four gene fusions. Limit of detection (LOD) studies employed AcroMetrix Mutant Hotspot Control and SeraSeq Lung and Brain CNV Mix. Microsatellite instability (MSI) and tumor mutational burden (TMB) were quantified. Inter- and intra-run reproducibility were evaluated to assess precision. Results: The CGP assay demonstrated high analytical performance, with >99% sensitivity, 100% specificity, and complete accuracy for variant detection. LOD studies revealed robust detection of SNVs at ≤5% variant allele frequencies (VAF) and CNVs at three copies. MSI and TMB results were consistent with clinical expectations, showing minimal bias compared to the orthogonal panel. Inter- and intra-run testing confirmed 100% reproducibility, indicating strong assay precision. Post-sequencing variant reporting was streamlined using the iCare platform, enabling direct FASTQ-to-report generation without intermediate bioinformatic steps. Conclusions: These findings support the present assay’s clinical utility in personalized oncology assessment. Full article

HCT116 is a colorectal cancer cell line frequently used in anti-tumor drug development experiments as well as in studies of the molecular machinery of eukaryotic cells. It is well characterized by the presence of several single-nucleotide and short mutations in multiple oncogenes and tumor suppressor genes, including KRAS, PIK3CA, MLH1, CTNNB1, CDKN2A, TGFBR2, and BRCA2. However, its landscape of large genomic rearrangements (LGRs) and copy number variants (CNVs) is still far from being fully understood. Therefore, the aim of this study was to identify LGRs and CNVs in several HCT116 cell line samples using Oxford Nanopore sequencing technology, including three samples from the SRA NCBI database, and to compare common and unique variants across all samples. Using the recently developed eLaRodON tool, we identified 22,666 common LGRs, among which more than 70% of tandem duplications and deletions larger than 80 kb were confirmed by CNV analysis. Among LGRs affecting protein-coding sequences, two in-frame rearrangements were identified: a deletion of exons 4–6 and a duplication of exon 10 in the CCSER1 gene, which encodes a cell division regulator protein. Given its high rearrangement rate in various tumors and the clinical significance of its overexpression, this finding may be potentially useful in future research on this cell line. Regarding differences between samples, we found that LGRs in the laboratory sample and in one of the three SRA NCBI samples occurred more frequently via ALR/Alpha repeats than via Alu repeats, in contrast to common LGRs and those unique to the other samples, a finding that may indicate the presence of unique mechanisms of genomic instability. Thus, this study reveals a broad spectrum of large genomic rearrangements and copy number variants that can be identified in the HCT116 cell line using Oxford Nanopore sequencing, including rearrangements specific to distinct cell line samples. Full article

Chromosomal microarray analysis (CMA) is widely used to detect chromosomal aneuploidies and copy number variants (CNVs) in pediatric patients with congenital anomalies or developmental concerns. However, its diagnostic utility in critically ill neonates and children admitted to intensive care units (ICUs) remains undercharacterized. We conducted a retrospective review of 679 patients admitted to the neonatal, pediatric, or cardiovascular intensive care units (NICU, PICU, CVICU) at Phoenix Children’s Hospital between 2019 and 2024 who underwent CMA. Demographic data, clinical indications, and CMA results were extracted from electronic medical records to assess diagnostic yield and variant patterns. CMA identified a clinically relevant finding in 102 of 679 patients, resulting in an overall diagnostic yield of 15.0% (95% CI: 12.3–17.7%). Clinically relevant findings included pathogenic (P) variants (n = 88), likely pathogenic (LP) variants (n = 12), and large regions of absence of heterozygosity (AOH) consistent with uniparental disomy (UPD) (n = 2). A variant of uncertain significance (VUS) was detected in 139 patients (20.5%). Among the pathogenic and likely pathogenic variants, CMA identified recurrent CNVs (n = 49), nonrecurrent CNVs (n = 17), aneuploidies (n = 22), and patients with two pathogenic or likely pathogenic CNVs (n = 10). Diagnostic yields of 48.4% (95% CI: 38.5–58.4%) and 8.4% (95% CI: 6.0–11.5%) were observed in patients with single or multiple congenital anomalies including a congenital heart defect (CA + CHD), and in patients with an isolated CHD, respectively. CMA demonstrates significant diagnostic value in critically ill neonates and children, particularly among those with multisystem congenital anomalies. These findings support the routine integration of CMA in genomic evaluation protocols for ICU populations to guide diagnosis, management, and counseling. Full article

Copy number variants (CNVs) are genomic rearrangements that carry a substantial risk for neurodevelopmental and neuropsychiatric disorders. Among these, recurrent deletions and duplications at the 16p11.2 locus are robustly associated with autism spectrum disorders, schizophrenia, epilepsy, and related conditions, yet also display marked variability in penetrance and phenotypic expression. Accumulating evidence indicates that 16p11.2 gene dosage influences multiple stages of brain development, from early progenitor dynamics and neuronal migration to synaptic formation, refinement, and plasticity. However, how disruptions across these processes are integrated over time, and how they relate to the observed variability and incomplete penetrance, remains poorly understood. In this review, we summarize the current evidence on the impact of 16p11.2 CNVs on brain development, focusing on cellular and circuit-level processes that shape neural connectivity. We discuss how gene dosage imbalance influences early developmental trajectories, synaptic formation and pruning, interneuron maturation, and activity-dependent plasticity, and consider how these processes interact across developmental stages. We suggest a conceptual framework wherein 16p11.2 CNVs do not impose fixed pathogenic outcomes, but rather they contribute towards developmental constraints that shape the timing and stability of neural circuit development. Consequently, these constraints increase vulnerability to neurodevelopmental and psychiatric outcomes in a context-dependent manner. Full article

Host genetic susceptibility to urogenital Chlamydia trachomatis (Ct) reinfection remains poorly understood. Coding variants identified in prior genome-wide association studies (GWAS) explained only a small fraction of the risk of reinfection. Our goal in this study was to characterize whether more risk would be captured by sequence variation that traditional GWAS insufficiently captures. Specifically, we evaluated the risk attributable to SNPs present in regulatory, non-coding regions; post-transcriptional regulation by microRNAs (miRNAs) that may depend on sequence variation in either the miRNA or the target mRNA; and copy number variants (CNVs). We analyzed GWAS data from African American women with or without documented urogenital Ct reinfection. Fine mapping and independent association analyses identified 30 unique index single-nucleotide polymorphisms (iSNPs), which were expanded to variants in linkage disequilibrium. Regulatory annotation was performed using HaploReg, RegulomeDB, FORGEdb, rSNPBase, and GTEx. We examined whether genes identified in the Ct reinfection GWAS are targeted by known Ct infection–associated microRNAs using curated databases. Genome-wide CNV calling was conducted using SNP intensity data, followed by stringent quality control and gene-level association testing. Functional annotation prioritized 7 SNPs with strong regulatory evidence, with stringent criteria for regulatory relevance, using HaploReg, RegulomeDB, FORGEdb, and rSNPBase. The strongest signals were observed at the CHIT1 locus, where multiple intronic variants (including rs2486963 and rs2244385) overlapped regulatory chromatin, altered transcription factor binding motifs, and acted as cis-expression quantitative trait loci for CHIT1 in whole blood. Additional regulatory variants were identified near TDRP, ERICH1, and DLGAP1, showing tissue-specific regulatory effects. MicroRNA analysis revealed extensive post-transcriptional targeting of SOCS6 and SULF1, while CHIT1 showed no curated Ct-associated miRNA interactions. CNV analysis identified 5775 high-confidence events, with nominal gene-level associations observed for ATAD3A, CARD14, TMEM240, and ZNF140. These results indicate that a greater fraction of the susceptibility to urogenital Ct reinfection may be driven by genetic variation affecting immune and epithelial pathways rather than protein-coding changes. Full article

Congenital heart defects (CHDs) are the most common congenital anomalies, with identifiable genetic etiologies in approximately 5–30% of affected infants, depending on the clinical presentation and comorbidities. This study included 216 children with CHD, predominantly syndromic, to explore the role of genetic variants in their morphological phenotypes. Chromosomal microarray (CMA) and whole-exome sequencing (WES) were performed, revealing clinically significant copy number variations (csCNVs) in 59 (27.3%) patients. The most frequent were 22q11.21 (8/59; 13.6%) and 7q11.23 (5/59; 8.5%) deletions. WES was conducted in 28.0% of cases, achieving a detection rate of 29.5%, primarily identifying variants related to Noonan syndrome. Genetic diagnoses were confirmed in 33.3% of patients, with clinically significant CNVs and SNV/INDELs found exclusively in those with syndromic CHD, leading to a 36.5% diagnosis rate in those patients. The identified variants most frequently affected genes encoding transcription factors (40.4%), followed by genes involved in the RAS signaling pathway and structural proteins (17.0%), and chromatin remodeling proteins (12.8%). Full article

Background: Autosomal recessive intellectual developmental disorder-13 (MRT13; OMIM #613192) is a rare neurodevelopmental disorder caused by pathogenic variants in TRAPPC9. Most reported variants are single-nucleotide variants (SNVs), small insertions/deletions, or copy number variants (CNVs), whereas complex structural variants (SVs) remain poorly characterized. Objectives: This study sought to review the clinical and molecular spectrum of TRAPPC9-related disorder, harmonize reported variants, explore genotype–phenotype correlations, and expand the mutational spectrum by reporting a novel patient with a cryptic SV. Methods: We report a novel patient whose diagnostic workup included array-CGH, whole-exome sequencing, karyotyping, and optical genome mapping. Additionally, a systematic literature search was primarily conducted in PubMed/MEDLINE from 2009 to January 2026, with Embase, Web of Science, Google Scholar, Orphanet, OMIM, and ClinVar used as supplementary sources. Patients carrying pathogenic/likely pathogenic TRAPPC9 variants were included. Clinical and molecular data were extracted and descriptively summarized. Genotype–phenotype correlations were explored. Reported variants were re-annotated using MANE Select reference transcripts. Results: The reported patient showed biallelic TRAPPC9 disruption due to two independently inherited structural variants: a maternal ~35 kb intragenic deletion involving exons 10–12, identified by 400K array-CGH, and a paternal balanced translocation t(4;8) disrupting TRAPPC9 within intron 8, characterized by trio-OGM and paired-end whole-genome sequencing (PE-WGS). Thirty-one studies reporting 75 previously published patients were included in the literature review; together with the novel patient described here, the final cohort comprised 76 patients. Intellectual disability was present in 100% of cases, followed by brain MRI abnormalities (95.9%), microcephaly (82.3%), motor delay (71.4%), dysmorphic features (69.8%), obesity (52.8%), behavioral abnormalities/autism spectrum disorder (49.2%/43.8%), and epilepsy (15.9%). Most patients (84.2%) harbored homozygous variants. Thirty-two distinct sequence variants were identified, predominantly loss-of-function. CNVs were identified in 13.2% of patients. No genotype–phenotype correlations were identified. Conclusions: The systematic review provides an updated and harmonized overview of the clinical and molecular spectrum of TRAPPC9-related disorder, supporting the presence of a recognizable phenotype and confirming the predominance of loss-of-function variants. Our case further highlights the contribution of cryptic structural variants to the mutational spectrum of TRAPPC9 and the diagnostic value of advanced genomic approaches. Full article

Background: Non-invasive prenatal testing (NIPT) based on analysis of Cell-Free Fetal DNA has transformed screening for common aneuploidies and is increasingly extended to genome-wide detection of copy number variants (CNVs). However, CNV detection remains constrained by analytical limitations and biological signal complexity. Methods: This review evaluates the analytical validity, biological constraints, and clinical interpretation challenges of CNV detection by NIPT, framing it as a probabilistic genomic inference rather than a direct measure of fetal copy number. Results: Performance depends on sequencing depth, bin resolution, fetal fraction, guanine–cytosine correction, and reference modeling, leading to variable detection thresholds. The predominantly placental origin of cfDNA introduces discordance through Confined Placental Mosaicism, post-zygotic events, and clonal variation. Maternal CNVs, mosaicism, vanishing twin, and occult malignancy further complicate interpretation and may cause false positives. Clinical validity is heterogeneous, with positive predictive value dependent on CNV size, genomic context, and prevalence. Reporting practices remain inconsistent. Conclusions: CNV detection by NIPT is fundamentally limited by interpretation of a composite maternal–placental signal. Progress requires improved tissue-of-origin discrimination, multi-omic integration, and standardized reporting to ensure responsible clinical implementation. Full article

Pangenomics has become an important framework for representing genetic diversity beyond a single linear reference genome. In agricultural species, it improves access to structural variants (SVs), copy number variations (CNVs), presence/absence variations (PAVs), and non-reference regulatory or coding sequences that may contribute to domestication, adaptation, and breeding traits. This review summarizes recent progress in long-read sequencing, telomere-to-telomere (T2T) assembly, and graph-based genome analysis, with emphasis on both livestock and crop systems. We first define the conceptual boundary between pangenome representations and reference-based variant catalogs. We then compare three major technical routes: variant integration, reference-guided iterative graph construction, and reference-free graph construction. Their performance is evaluated in terms of accuracy, scalability, coordinate consistency, reference bias, computational demand, annotation transfer, and suitability for downstream breeding questions. We further discuss how pangenome resources support hidden variant discovery, QTL and GWAS interpretation, environmental adaptation analysis, and multi-omics-based candidate prioritization. Importantly, we highlight unresolved limitations, including graph complexity, pipeline-dependent SV calls, incomplete functional annotation, weak cross-study comparability, and the difficulty of distinguishing causal variants from linked or neutral variation. This review therefore treats pangenome studies as connected but non-equivalent evidence: resource-building studies establish representational breadth, method papers define technical feasibility, and trait-focused studies provide varying levels of biological support. Apparent inconsistencies among studies are interpreted as signals of differences in sampling, genome complexity, validation depth, and graph construction strategy rather than as simple disagreements. Full article

Background: Evaluation of gene-level copy number variants (CNVs) for diagnosis and therapeutic decision making has become standard of care with next-generation sequencing (NGS), immunohistochemistry (IHC), and/or fluorescence in situ hybridization (FISH) being used to detect gene amplifications/deletions in tumor tissue. In contrast to most solid tumors, CNS cancers are challenging to evaluate by resection and/or biopsy due to the associated risks with invasive brain surgery that can also result in death or associated morbidity and therefore alternate methods are required.Methods: This study presents the analytical validation of using quantitative PCR (qPCR) to detect gene CNVs directly from cerebrospinal fluid (CSF)-derived DNA and from the Ascent^TM low-pass whole genome sequencing (LP-WGS) libraries, demonstrating concordance with the gold standard of NGS/IHC/FISH used in tumor tissue. Results: The analytical sensitivity of qPCR to detect gene amplification calls for ERBB2 (erb-b2 receptor tyrosine kinase 2) was demonstrated to be 100% and that of EGFR (epidermal growth factor receptor) was 83%, with specificities of 96% and 100%, respectively. The analytical sensitivity of qPCR to detect gene deletions for CDKN2A/2B (cyclin-dependent kinase inhibitor 2A/2B) was 60% and that for MTAP (methylthioadenosine phosphorylase) was 100% with a specificity of 100% for all three genes. Ascent^TM was demonstrated to have a higher sensitivity (100%) when compared to qPCR for the same genes evaluated and demonstrated 100% positive agreement and 100% negative agreement with known CNV status. Conclusions: The results demonstrate that given the paucity of cells in CSF limiting the use of IHC and FISH, qPCR and Ascent^TM provide highly sensitive, novel, minimally invasive methods for the evaluation of gene copy number (CN) status to inform the diagnosis and management of CNS cancers. Full article

Background/Objectives: Genomic alterations play a central role in diagnosis, prognostication, and therapeutic planning for hematolymphoid malignancies. At our tertiary care center, frontline genomic testing relies on optical genome mapping, karyotyping, and fluorescence in situ hybridization, with targeted next-generation sequencing (NGS) performed externally. To provide more comprehensive genomic profiling, we evaluated two large-panel NGS platforms and subsequently performed a clinical validation of the selected assay. Methods: The Illumina PanHeme DNA panel and the SOPHiA Genetics Community Myeloid Solution were compared using 24 bone marrow aspirate specimens with previously characterized alterations, including single nucleotide variants (SNVs), insertions/deletions (indels), and copy number variants (CNVs). The selected panel underwent full analytical validation using 60 specimens. Results: Both panels demonstrated excellent concordance for SNVs and indels, with comparable analytical performance and workflow. CNV calling with SOPHiA was notably strong. Platform selection was influenced by practical considerations, including panel content and cost, leading to a preference for further evaluation of the Illumina assay. Clinical validation of the Illumina PanHeme DNA panel, along with a complementary RNA Exome panel, was subsequently performed. Sequence variant detection showed 100% concordance with orthogonal testing, while CNV detection was variable, reflecting known limitations of targeted NGS. The RNA panel detected all expected fusion transcripts. Conclusions: These findings demonstrate robust analytical performance of both evaluated DNA panels. Clinical validation of the Illumina PanHeme DNA and RNA Exome assays supports their use for comprehensive molecular profiling of hematologic malignancies. Full article