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Deep clinical and genetic analysis of 17p13.3 region: 38 pediatric patients diagnosed using next-generation sequencing and literature review.

BACKGROUND: Chromosome 17p13.3 is a region of genomic instability associated with different neurodevelopmental diseases. The malformation spectrum of 17p13.3 microdeletions ranges from an isolated lissencephaly sequence to Miller-Dieker syndrome, while 17p13.3 microduplications result in autism, learning disabilities, microcephaly and other brain malformations. This study aims to provide a more comprehensive delineation of the clinical and genetic characteristics associated with 17p13.3 alterations. METHODS: We retrospectively analyzed the next-generation sequencing (NGS) data of more than 40 thousand patients from January 2016 to December 2021 and identified 38 pediatric patients with copy-number variations (CNVs) or single-nucleotide variations (SNVs) in 17p13.3 region. Published patients with CNVs in the 17p13.3 region were also collected and we performed a Chi-square test to compare the phenotype spectrum of microdeletions and microduplications. RESULTS: Among the 27 CNV patients, 20 patients with microdeletions and 7 patients with microduplications were found. PAFAH1B1 was the most frequently deleted gene and CRK was the most frequently duplicated gene. Affected genes in 11 SNV patients included PAFAH1B1 and PRPF8. Developmental delay was the most common abnormality detected in the 38 patients (29/38, 76.3%). Of note, Case 10 presented omphalocele and Case 23 presented scoliosis, webbed neck and bone cyst, all of which were unusual variant phenotypes in this region. The Chi-square test revealed that epilepsy, lissencephaly and short stature were statistically significant with microdeletions, while behavioral abnormalities and hand and foot abnormalities were significant with microduplications (p&#x2009;<&#x2009;0.01). CONCLUSIONS: While PAFAH1B1, YWHAE and CRK are associated with major phenotypes of 17p13.3, RTN4RL1 may be involved in white matter changes and HIC1 might contribute to the occurrence of omphalocele. This study provided a comprehensive understanding of genetic information and phenotype spectrum of the 17p13.3 region.

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Detection of Tumor Suppressor Genes Rare Variants: Findings From Neuroblastoma Using Next-Generation Sequencing.

BACKGROUND/OBJECTIVES: Neuroblastomas (NB) influenced by genetic alterations, which plays significant role in disease progression. Tumor suppressor genes (TSGs) are crucial in regulating cell growth, suppressing replication, and inducing apoptosis to prevent cancer formation. However, mutations in TSGs can lead to loss of normal activity, contributing to cancer development. This study aimed to identify TSG variants in NB patients and assess their clinical significance. METHODS: One hundred two NB patients diagnosed and monitored according to the International Neuroblastoma Risk Group Staging System (INRGSS) protocol were included in this study. DNA was extracted from paraffin-embedded tissue samples, and Next-Generation Sequencing (NGS) was conducted using the Pillar ONCO/Reveal Multi-Cancer v4 panel. RESULTS: The most frequently recurring TSG variant detected was RB1, p.P793S (n&#x2009;=&#x2009;21; 25%) followed by ATM, p.D1853N (n&#x2009;=&#x2009;20, 19.6%).Stop-gain variants were identified in TP53 (p.R196*), FBXW7 (p.R367*), and PTEN (p.G129*). CONCLUSIONS: Our findings underscore the significance of specific TSG variants in NB, particularly in relation to disease progression and potential prognostic markers. Further research is needed to comprehensively assess the role of TSGs in NB, with an emphasis on germline variants and protein expression in larger patient cohorts.

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Metagenomic next-generation sequencing of cerebrospinal fluid reveals pathogen spectrum and mortality predictors among patients with advanced HIV-1 disease at a tertiary hospital in China.

BACKGROUND: Central nervous system (CNS) infections remain the major causes of morbidity and mortality among people living with HIV-1 (PLWH), particularly in resource-limited settings. However, the clinical characteristics and prognostic indicators of PLWH with suspected CNS infections are not well defined. In this study, we aim to characterize the spectrum of CNS pathogens, clinical characteristics, in-hospital mortality, and factors associated with death among people with advanced HIV-1 disease (AHD) in Guangxi, China. METHODS: Metagenomic next-generation sequencing (mNGS) was performed to analyze types of infection in cerebrospinal fluid (CSF) from 61 treatment-naive PLWH with suspected CNS infections. Clinical data, routine laboratory tests, and biochemical tests were collected and analyzed. RESULTS: Among the 61 CSF samples, primarily with AHD, a total of 206 pathogens were identified. Viral pathogens predominated, with Epstein-Barr virus being the most frequently identified, followed by cytomegalovirus. Compared with patients with single-pathogen infection, those with multiple infections (viral, bacterial, and fungal) exhibited significantly lower CD4 T cell counts, higher C-reactive protein levels, and markedly reduced lipid metabolism parameters. However, infection types were not significantly associated with in-hospital death. Multivariate logistic regression analysis identified plasma low density lipoprotein (LDL) and CSF lactate dehydrogenase (LDH) as independent predictors of in-hospital death. CONCLUSION: In PLWH with AHD and suspected CNS infections, multiple pathogens frequently coexist in the CSF. Plasma LDL and CSF LDH levels were independent predictors of death, indicating their potential value as early risk stratification in AHD.

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Extraction, Purification, and Next-Generation Sequencing (NGS) Analysis of DNA and RNA from Formalin-Fixed and Paraffin-Embedded (FFPE) Tissue.

Formalin fixed paraffin embedded (FFPE) tissues have long been used for immunohistological analyses. FFPE tissues can be stored at room temperature for several years enabling analyses to be performed later. Ease of storage and transport makes these tissues an attractive source of biological material. However, formalin fixation results in chemical modifications of proteins and nucleic acids that poses a major challenge to any type of analysis. Recovery of nucleic acids for quantitative assays is rendered difficult due to degradation resulting from fixation and long-term storage, producing low usable yields. Extensive efforts in the last 20&#xa0;years have led to significant improvements in use of FFPE tissues for DNA and RNA analyses and resulted in development of sensitive assays for a wide range of applications, including next-generation sequencing. In this chapter, we describe the optimization of methods for sequential extraction of DNA and RNA from FFPE tissue and subsequent preparation of DNA-seq and RNA-seq libraries for use with the Illumina platform using commercially available reagents/kits.

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Copy Number-low/TP53-mutated Endometrial Cancer With Wild-type p53 Immunoexpression: Implications for Risk Stratification and Management When Using Next-generation Sequencing for Molecular Classification.

Endometrial cancers with the Cancer Genome Atlas (TCGA) molecular profile of TP53-mutated, POLE-wild-type, and microsatellite-stable generally exhibit a high burden of copy number (CN) alterations and carry an increased risk for adverse outcomes, meriting maximal adjuvant therapy. In contrast, the prognosis associated with a TP53 mutation that coexists with a POLE mutation or microsatellite instability aligns with that of ultramutated or hypermutated cancers, respectively. In this study, we characterized a rare molecular subclass of endometrial cancers defined by TP53 mutation but low burden of CN alterations, wild-type p53 immunoexpression (immunohistochemistry [IHC]), and low TP53 variant allele frequency (median 13% and maximum 47%). Among 723 consecutive endometrial cancers prospectively classified using next-generation sequencing, 16 (2.2%) were CN-low/TP53-mutated/p53 wild-type IHC. Two additional cases were identified in a separate retrospective cohort of 32 recurrent low-grade early-stage endometrial cancers, bringing the total to 18 cases. They affected postmenopausal patients, exhibited low-grade endometrioid histotype, and were mostly confined to the uterus without lymphovascular space invasion. The recurrence rate was 6.25% (1/16) in the prospective cohort, and none died, placing their prognosis closer to that of CN-low than CN-high cancers. We conclude that next-generation sequencing-based TCGA classification of TP53-mutated, POLE-wild-type, microsatellite-stable endometrial cancers with TP53 variant allele frequency < 50% requires further evaluation using CN analysis and/or p53 IHC to detect this rare molecular category. IHC-based TCGA classification, such as the ProMisE protocol, will not be able to detect these cases because the p53 IHC pattern is wild-type and there are no distinguishing morphological features; this may be of relevance for analyzing ProMisE protocol-based clinical trials and outcomes studies. Long-term outcome studies are needed to refine risk stratification and treatment decisions for this unique molecular class of endometrial cancers that further contributes to the evolving understanding that the clinical significance of TP53 mutation in endometrial cancer is complex and depends on coexisting molecular alterations.

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Characteristics of p53 and Smad4 immunohistochemistry in pancreatic ductal adenocarcinoma and validation by next-generation sequencing.

BACKGROUND: Mutations in four major driver genes -KRAS, CDKN2A, TP53, and SMAD4- are central to the pathogenesis of pancreatic ductal adenocarcinoma (PDAC) and critically inform diagnosis, therapeutic decision-making, and prognostic assessment. Although next-generation sequencing (NGS) is widely regarded as the gold standard for detecting these mutations, its clinical application is often limited by suboptimal analytical efficiency and substantial economic cost. Among these genes, immunohistochemical (IHC) staining for the proteins encoded by TP53 and SMAD4 has been extensively adopted in routine pathology practice. However, standardized IHC pattern classification schemes and rigorous validation of their predictive accuracy for underlying genomic alterations remain lacking in PDAC. METHODS: We retrospectively enrolled 63 PDAC patients and systematically characterized the typical IHC expression patterns of p53 and Smad4. Targeted NGS was subsequently performed on all available tumor specimens, and the resulting mutational profiles were correlated with corresponding IHC findings. Diagnostic performance including sensitivity, specificity and accuracy of p53 IHC for predicting TP53 mutations and of Smad4 IHC for predicting SMAD4 mutations was rigorously evaluated. RESULTS: Among the four canonical driver genes, co-occurring double- or triple-gene mutations were prevalent; within TP53 and SMAD4, missense mutations constituted the most frequent variant type. Using NGS as the reference standard, we validated the diagnostic utility of a three-tiered p53 IHC classification system, particularly in fine-needle biopsy (FNB) specimens. Furthermore, we proposed a novel, refined Smad4 IHC pattern classification that incorporates an "intermediate" category, thereby expanding upon conventional binary interpretation. This new scheme achieved markedly improved mutation prediction accuracy (0.76) compared with traditional approaches (0.57). CONCLUSION: Our study highlights the complementary diagnostic value of p53 and Smad4 IHC relative to molecular testing in PDAC, especially when tissue is limited, as commonly encountered in FNB specimens. The newly established Smad4 IHC classification system, which integrates an intermediate expression category into the conventional two-tier framework, demonstrates superior clinical utility and enhances predictive accuracy for SMAD4 genomic alterations.

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Analysis of HLA Allelic and Haplotypic Frequencies in a Cohort of Bone Marrow Donors in Catalonia: Impact of Next-Generation Sequencing on Donor Registry Quality.

In haematopoietic stem cell transplantation (HSCT), the volunteer unrelated donor (VUD) has become the most common strategy in Europe, as improved outcomes are achieved through HLA compatibility at allelic-level resolution. In this context, the implementation of next-generation sequencing (NGS) in histocompatibility typing laboratories has significantly enhanced the quality of bone marrow registries, enabling a high level of resolution at a lower cost and improved performance. In this study, we analyse a large cohort of 21,787 bone marrow donors in Catalonia and present the observed HLA allelic and haplotypic frequencies, along with their linkage disequilibria. HLA-A, -B, -C, -E and -G were genotyped at full resolution, while -DRB1, -DQB1, -DQA1, -DPA1 and -DPB1 were genotyped at high resolution. We identified 236 new officially named HLA alleles, both coding and non-coding regions. This study highlights that the implementation of high-throughput HLA typing has led to an increase in the number of registered donors and an improvement in quality, which has been reflected in a rise in the number of effective donors.

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Targeted next-generation sequencing for drug-resistant tuberculosis diagnosis: implementation considerations for bacterial load, regimen selection and diagnostic algorithm placement.

INTRODUCTION: Early and accurate diagnosis of drug-resistant tuberculosis (DR-TB) is essential for improving treatment outcomes. Phenotypic drug susceptibility testing (pDST) is comprehensive but slow, while rapid molecular assays provide resistance information for a limited number of drugs. Targeted next-generation sequencing (tNGS) offers the potential for broad and rapid resistance detection, but its integration into diagnostic algorithms has been hindered by uncertainty about its placement within existing workflows. METHODS: This study evaluated the extent to which two tNGS solutions-Deeplex Myc-TB (GenoScreen) and TB Drug Resistance Test (Oxford Nanopore Technologies, ONT)-provided interpretable drug resistance results that could inform regimen design, in comparison to other WHO-recommended molecular assays and pDST. Data were collected from three high-burden DR-TB settings under the Seq&Treat study. Sequencing success rates and drug resistance detection were analysed based on: (1) the initial Xpert MTB/RIF result (very low, low, medium, high), (2) resistance results for drugs in WHO-recommended regimens and (3) performance relative to other WHO-endorsed assays. The potential impact of different algorithms on the estimates was also considered. Key factors influencing successful tNGS adoption within diagnostic pathways were identified, leveraging insights from the Seq&Treat diagnostic accuracy study. RESULTS: Sequencing success rates were 88.5% (GenoScreen) and 93.1% (ONT) across 763 samples. While tNGS provided complete resistance data for 73%-86% of drugs in recommended regimens, pDST achieved 92%-93%. Both tNGS solutions matched or exceeded the sensitivity of WHO-recommended molecular assays. CONCLUSIONS: This study highlights the critical role of tNGS as a centralised tool for comprehensive drug resistance testing to inform DR-TB treatment decisions following initial screening assays. By complementing existing molecular tests with tNGS, diagnostic workflows can be optimised to ensure timely and comprehensive resistance detection. These findings support policy updates to integrate tNGS into global TB diagnostic algorithms. TRIAL REGISTRATION NUMBER: NCT04239326.

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Identification of autosomal and sex chromosome aneuploidies using next generation sequencing.

MOTIVATION: Chromosomal abnormalities, referred to as aneuploidies, occur in approximately 0.3% of live births. While the majority of aneuploidies in humans are incompatible with life, well-characterized exceptions include Down syndrome (47,+21), Patau syndrome (47,+13), Edwards syndrome (47,+18), Turner syndrome (45,X0), Klinefelter syndrome (47,XXY), and triple X syndrome (47,XXX). These chromosomal alterations disrupt gene expression and cellular function, leading to genetic and developmental disorders. With the increasing adoption of next generation sequencing (NGS) in clinical diagnostics, this study aims to explore the potential use of NGS for aneuploidies detection. RESULTS: Using data derived from clinical exomes (CES) and whole exomes (WES) sequencing we have been able to detect autosomal as well as sex chromosome aneuploidies with high specificity. Moreover, we have also been able to identify mosaic aneuploidies proving the high sensibility of this methodological approach. Thus, we present NGS as a cost-effective first line approach to detect chromosomal aneuploidies in routine diagnostic practice. AVAILABILITY AND IMPLEMENTATION: Scripts are available at https://github.com/B-R-I-D-G-E/AneuploidiesStudies.

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Genetic Analysis of Early Neoplasia in the Breast: Next-Generation Sequencing of Flat Epithelial Atypia and Associated Ductal and Lobular Lesions.

The molecular features of invasive breast cancers (IBC) have been well-characterized, but less is known about the earlier stages of neoplasia, including oncogenic drivers in early intraductal lesions. Flat epithelial atypia (FEA) is considered the earliest recognized precursor in the low-grade neoplasia pathway, but its mutational repertoire has not been studied, and drivers of the transition to morphologically more advanced lesions are unknown. Herein, we utilized next-generation sequencing to analyze 39 synchronous lesions from 13 patients, including FEA (n = 12) or predominantly FEA with early atypical ductal hyperplasia (FEA/early atypical ductal hyperplasia [ADH], n = 5) and associated ADH (n = 2), ductal carcinoma in situ (ductal carcinoma in situ [DCIS], n = 11), lobular carcinoma in situ (n = 3), and/or IBC with ductal and/or lobular differentiation (n = 6). Aside from 1 DCIS sample, all sequenced lesions in each patient were clonally related to one another. Recurrent alterations in FEA and FEA/early ADH included PIK3CA (69%), NCOR1 (31%), CBFB (31%), RUNX1 (15%), and GATA3 (23%). The mutational repertoire of FEA was similar to The Cancer Genome Atlas luminal IBC, except CBFB and NCOR1 mutations, which were more frequent in FEA and (along with PIK3CA, FOXA1, and CDKN1B) not always identified in paired morphologically advanced lesions. Compared with FEA, DCIS had more mutations and chromosomal copy number changes, including aberrations in PI-3 kinase pathway, transcription factors, chromatin remodeling genes, and TP53. CDH1 mutations identified in lobular carcinoma in situ were absent in paired FEA. Analysis of cases with ductal and lobular heterogeneity, including Rosen's triad, confirmed the shared clonality of the ductal and lobular components with features of genetic divergence. IBC of no special type were genetically similar to DCIS, and tubular carcinomas were similar to FEA. The results reveal the mutational repertoire of FEA and the genetics of early breast neoplasia, highlighting the clonal relationships of FEA to ductal and lobular carcinomas. Luminal breast cancer-associated genetic alterations are present at the earliest morphologically recognized stages of neoplasia.

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Evaluating culture-free targeted next-generation sequencing for diagnosing drug-resistant tuberculosis: a multicentre clinical study of two end-to-end commercial workflows.

BACKGROUND: Drug-resistant tuberculosis remains a major obstacle in ending the global tuberculosis epidemic. Deployment of molecular tools for comprehensive drug resistance profiling is imperative for successful detection and characterisation of tuberculosis drug resistance. We aimed to assess the diagnostic accuracy of a new class of molecular diagnostics for drug-resistant tuberculosis. METHODS: We conducted a prospective, cross-sectional, multicentre clinical evaluation of the performance of two targeted next-generation sequencing (tNGS) assays for drug-resistant tuberculosis at reference laboratories in three countries (Georgia, India, and South Africa) to assess diagnostic accuracy and index test failure rates. Eligible participants were aged 18 years or older, with molecularly confirmed pulmonary tuberculosis, and at risk for rifampicin-resistant tuberculosis. Sensitivity and specificity for both tNGS index tests (GenoScreen Deeplex Myc-TB and Oxford Nanopore Technologies [ONT] Tuberculosis Drug Resistance Test) were calculated for rifampicin, isoniazid, fluoroquinolones (moxifloxacin, levofloxacin), second line-injectables (amikacin, kanamycin, capreomycin), pyrazinamide, bedaquiline, linezolid, clofazimine, ethambutol, and streptomycin against a composite reference standard of phenotypic drug susceptibility testing and whole-genome sequencing. FINDINGS: Between April 1, 2021, and June 30, 2022, 832 individuals were invited to participate in the study, of whom 720 were included in the final analysis (212, 376, and 132 participants in Georgia, India, and South Africa, respectively). Of 720 clinical sediment samples evaluated, 658 (91%) and 684 (95%) produced complete or partial results on the GenoScreen and ONT tNGS workflows, respectively, with 593 (96%) and 603 (98%) of 616 smear-positive samples producing tNGS sequence data. Both workflows had sensitivities and specificities of more than 95% for rifampicin and isoniazid, and high accuracy for fluoroquinolones (sensitivity approximately &#x2265;94%) and second line-injectables (sensitivity 80%) compared with the composite reference standard. Importantly, these assays also detected mutations associated with resistance to critical new and repurposed drugs (bedaquiline, linezolid) not currently detectable by any other WHO-recommended rapid diagnostics on the market. We note that the current format of assays have low sensitivity (&#x2264;50%) for linezolid and more work on mutations associated with drug resistance is needed. INTERPRETATION: This multicentre evaluation demonstrates that culture-free tNGS can provide accurate sequencing results for detection and characterisation of drug resistance from Mycobacterium tuberculosis clinical sediment samples for timely, comprehensive profiling of drug-resistant tuberculosis. FUNDING: Unitaid.

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Metagenomic Next-Generation Sequencing for the Diagnosis of Trichomonas Vaginalis-Associated Empyema: a Case Report and Literature Review.

BACKGROUND: This report describes a rare case of empyema caused by Trichomonas vaginalis co-infected with Streptococcus agalactiae and Streptococcus pyogenes, aiming to explore the role of T. vaginalis in the development of empyema, its diagnostic methods, and treatment strategies. METHODS: The patient was a 46-year-old male who presented with cough, sputum production, and shortness of breath. The diagnosis was made using chest CT, routine pleural fluid analysis, bacterial culture, and metagenomic next-generation sequencing (mNGS). Pleural fluid examination revealed numerous motile Trichomonas organisms, and bacterial culture identified Streptococcus agalactiae and Streptococcus pyogenes as the pathogens. Fur-ther mNGS confirmed these bacteria as the causative agents, with 39 Trichomonas sequences detected, including 32 sequences specific to T. vaginalis. RESULTS: The patient received combination antimicrobial therapy and underwent chest tube drainage and thoracoscopic empyema debridement. Post-treatment, the patient's condition significantly improved. A literature review revealed that while Trichomonas tenax is a common pathogen in empyema, T. vaginalis is an extremely rare cause. T. vaginalis infection may be associated with bacterial co-infections, immunosuppression, or poor hygiene. CONCLUSIONS: This case is the first report of T. vaginalis induced empyema, expanding the understanding of Trichomonas infections. Although such infections are rare, they should be considered in high-risk patients. Further studies are needed to investigate the infection pathways of T. vaginalis and its mechanisms of bacterial synergy in disease pathogenesis to improve clinical diagnosis and treatment strategies.

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