Sequencing Panel Research Articles

Clinical Characteristics and Audiological Profiles of Patients with Pathogenic Variants of WFS1.

Background: Mutations in Wolfram syndrome 1 (WFS1) cause Wolfram syndrome and autosomal dominant non-syndromic hearing loss DFNA6/14/38. To date, more than 300 pathogenic variants of WFS1 have been identified. Generally, the audiological phenotype of Wolfram syndrome or DFNA6/14/38 is characterized by low-frequency hearing loss; however, this phenotype is largely variable. Hence, there is a need to better understand the diversity in audiological and vestibular profiles associated with WFS1 variants, as this can have significant implications for diagnosis and management. This study aims to investigate the clinical characteristics, audiological phenotypes, and vestibular function in patients with DFNA6/14/38. Methods: Whole-exome or targeted deafness gene panel sequencing was performed to confirm the pathogenic variants in patients with genetic hearing loss. Results: We identified nine independent families with affected individuals who carried a heterozygous pathogenic variant of WFS1. The onset of hearing loss varied from the first to the fifth decade. On a pure-tone audiogram, hearing loss was symmetrical, and the severity ranged from mild to severe. Notably, either both low-frequency and high-frequency or all-frequency-specific hearing loss was observed. However, hearing loss was non-progressive in all types. In addition, vestibular impairment was identified in patients with DFNA6/14/38, indicating that impaired WFS1 may also affect the vestibular organs. Conclusions: Diverse audiological and vestibular profiles were observed in patients with pathogenic variants of WFS1. These findings highlight the importance of comprehensive audiological and vestibular assessments in patients with WFS1 mutations for accurate diagnosis and management.

Single-center analysis of a real-world cohort of patients with metastatic urothelial carcinoma evaluated by NGS: molecular landscape and efficacy of targeted therapies.

To describe the molecular profile of a real-world cohort of patients with metastatic urothelial carcinoma (mUC) and to evaluate the benefit of next-generation sequencing (NGS) panels in guiding therapy in patients with mUC and the outcomes of DNA-matched treatments recommended by a multidisciplinary molecular tumor board (MMTB). This was a single-center analysis of a real-world cohort of adult patients with mUC included in an ongoing trial that aimed to evaluate the clinical utility of NGS for solid tumors. Genomic analysis was performed for each patient, most of them using the Ion Torrent Oncomine Focus Assay. Genomic results were discussed during MMTB meetings. We included 43 patients with mUC treated with platinum-based combinations and immunotherapy. Twenty-five patients (58.1%; 95% CI 43.4-72.9) had at least one tumor pathogenic alteration. The MMTB classified 16 (48.5%) of the 33 tumor pathogenic alterations found in our real-world cohort of mUC patients as ESCAT I, which is the maximum grade of actionability. After excluding patients who were not candidates for targeted therapies, the MMTB provided guidance on matched therapy for seven patients. Among these patients, three achieved a partial response for an overall response rate of 42.9%, a median progression-free survival of 7.3months (95% CI 6.7-7.9) and a median overall survival of 10.9months (95% CI 2.4-19.5). We recommend that all patients with mUC undergo NGS at diagnosis given the high percentage of patients with pathogenic alterations in our real-world cohort and the efficacy data of patients treated with targeted therapies.

Molecular profiling of an Indian EB cohort - a single centre experience.

Epidermolysis bullosa (EB) encompasses rare hereditary skin conditions marked by skin fragility, nail dystrophy, and minor trauma-induced skin blisters. This study aims to identify genetic variants in Indian EB patients and examine the relationship between genotypic and phenotypic manifestations. EB patients seen consecutively over a period of 5 years at Outpatient Department of Dermatology. Baseline demographic data, birth history, family history, skin manifestation at birth, past medical history, current cutaneous manifestations, and the evolution of the disease were assessed and recorded. Genetic variants were identified using targeted gene panel sequencing of 23 EB-related genes, and a genetic-phenotype analysis was performed. Our study included 65 patients with EB. Among 65 EB patients, 38 dystrophic EB cases (58.46%), 12 junctional EB (18.46%), 12 epidermolysis bullosa simplex (18.46%), and 3 Kindler EB (4.62%) were reported. Dominant and recessive forms of dystrophic EB accounted for 16.92% and 41.4%, respectively. We identified 75 unique genetic variants, 58.67% newly discovered and 41.33% previously reported. Compound heterozygous variations were more frequent (55.55%) than homozygous ones (44.44%) in recessive dystrophic EB patients. Junctional EB patients harboured LAMB3 gene mutations more frequently, while epidermolysis bullosa simplex patients showed KRT5 and KRT14 gene missense heterozygous mutations. Kindler EB patients had homozygous mutations in the FERTM1 gene. Our study unveiled several novel genetic variants; severe phenotypes associated with nonsense genetic variants. These findings offer valuable insights for future clinical assessments and tailored management strategies.

The K9 lymphoma assay allows a genetic subgrouping of canine lymphomas with improved risk classification

We present here the K9 lymphoma assay, a novel 31-gene targeted next-generation sequencing panel designed for genomic profiling of canine lymphoid neoplasms. Addressing the growing demand for advanced diagnostics in veterinary oncology, this assay enables sensitive identification of known and actionable mutations specific to canine lymphomas, while evaluating its prognostic potential to facilitate diagnosis and prognosis. Our analysis, spanning several B- and T-cell lymphoma histotypes, unveiled distinct mutational landscapes distinguishing tumors derived from immature versus mature lymphocytes. Clustering analysis revealed a shared genetic origin between diffuse large B-cell lymphoma and marginal zone lymphoma, aligning with findings in human lymphomas, with TRAF3 emerging as the most frequently mutated gene across B-cell lymphoma subtypes. Significantly, TP53 mutations demonstrated universal adverse prognostic implications across B-cell lymphomas. Additionally, SETD2 mutations contributed to shorter time-to-progression, underscoring the role of epigenetic dysregulation in B-cell tumors. In T-cell lymphomas, SATB1 and FBXW7 were frequently mutated, warranting further investigation in larger cohorts. Our findings advocate for tailored therapeutic approaches based on the genetic profile, impacting treatment decisions and outcomes in canine lymphoma management. This study provides pivotal insights bridging veterinary and human oncology, paving the way for comprehensive genomic diagnostics and therapeutic strategies in comparative oncology.

Genomic profiles and clinical presentation of chordoma

Chordoma is a rare bone cancer with variable clinical outcomes. Here, we recruited 184 sporadic chordoma patients from the US and Canada and collected their clinical and treatment data. The average age at diagnosis was 45.5 years (Range 5–78) and the chordoma site distribution was 49.2% clivus, 26.2% spinal, and 24.0% sacral. Most patients (97.5%) received surgery as the primary treatment, among whom 85.3% also received additional treatment. Except for the most prevalent cancers like prostate, lung, breast, and skin cancer, there was no discernible enrichment for any specific cancer type among patients or their family members. Among a subset of patients (N = 70) with tumor materials, we conducted omics analyses and obtained targeted panel sequencing and SNP array genotyping data for 51 and 49 patients, respectively. The most recurrent somatic driver mutations included PIK3CA (12%), followed by chromatin remodeling genes PBRM1 and SETD2. Amplification of the 6q27 region, containing the chordoma susceptibility gene TBXT, was detected in eight patients (16.3%). Clival patients appeared to be less likely to carry driver gene mutations, chromosome arm level deletion events (e.g., 5p, 5p, and 9p), or 6q27 amplification compared to sacral patients. After adjusting for age, sex, tumor site, and additional treatment, patients with somatic deletions of 14q (OR = 13.73, 95% CI 1.96–96.02, P = 0.008) and 18p (OR = 13.68, 95% CI 1.77–105.89, P = 0.012) were more likely to have persistent chordoma. The study highlights genomic heterogeneity in chordoma, potentially linked to location and clinical progression.

Bruton's tyrosine kinase inhibitor zanubrutinib-based regimens in relapsed/refractory primary diffuse large B-cell lymphoma of central nervous system.

30 Background: Patients with relapsed/refractory primary central nervous system lymphoma (R/R PCNSL) usually have a poor prognosis. Ibrutinib-based regimens revealed promising efficacy but showed off-target effects and drug resistance in some cases. Here, we conducted a retrospective study to evaluate the efficacy and safety of regimens based on second-generation bruton's tyrosine kinase (BTK) inhibitor zanubrutinib in R/R PCNSL. Methods: We respectively reviewed 23 patients with R/R PCNSL treated with zanubrutinib in our center from Apr. 2021 to Jan. 2024. The primary end points were overall response rate (ORR) and progression-free survival (PFS). Secondary end points included complete response rate (CRR), disease control rate (DCR), overall survival (OS) and adverse events (AEs). Response was assessed according to International Primary CNS Lymphoma Collaborative Group criteria. The severity of AEs was graded using the NCI Common Toxicity Criteria, version 5.0. Validated next-generation sequencing (NGS) panels were used to analyze the mutational status of the BCR pathway genes or other solid tumor-related genes. Results: The median follow-up at the cutoff date (15 Jan 2024) was 17.0 months (range, 2-33 months). The ORR, CRR and DCR were 78.3%, 39.1% and 91.3%. The median PFS was 31.0 months, but the median OS was not reached. Compared to germinal center B-cell like (GCB) group, non-GCB group showed a better ORR (76.9% vs 66.7%) and CRR (46.2% VS 33.3%). Multivariate analysis revealed that overall response (vs. no response, HR=0.20, P=0.027), long duration of zanubrutinib (≥6months vs. 2-5 months, HR=0.07, P=0.009) and refractory disease status (vs. relapse disease status, HR=0.12, P=0.014) were independent factors for longer PFS. The most commonly mutated genes are MYD88(15/17,88.2%), PIM1(9/17 52.9%), CD79B (8/17,47.1%), ETV6(7/17,41.2%), BTG1(5/17,29.4%) and GNA13(5/17,29.41%). The mutational status of MYD88/CD79B did not lead to any difference in PFS and OS. We obtained the Tumor Mutational Burden (TMB) information from 11 patients. The median TMB was 15.96 (range: 3.82-28.11) muts/Mb. Kaplan-Meier analysis demonstrated that PFS was significantly longer in patients with higher TMB (≥15.96 muts/Mb) after zanubrutinib-based treatment(P=0.005). Grade ≥3 and serious treatment-emergent AEs (TEAEs) were not found. The most commonly TEAEs were hematologic toxicity (8/23,34.8%) and skin rash (5/23,21.7%). Conclusions: Our study demonstrates that zanubrutinib-based therapy is effective and safe for the treatment of R/R PCNSL. We advocate for the prolonged administration of zanubrutinib to maintain treatment response. Patients with higher TMB derive greater benefits from zanubrutinib-based regimens.

Heterozygosity for loss-of-function variants in LZTR1 is associated with isolated multiple café-au-lait macules

PurposePathogenic LZTR1 variants cause schwannomatosis and dominant/recessive Noonan syndrome (NS). We aim to establish an association between heterozygous loss-of-function LZTR1 alleles and isolated multiple café-au-lait macules (CaLMs). MethodsA total of 849 unrelated participants with multiple CaLMs, lacking pathogenic/likely pathogenic NF1 and SPRED1 variants, underwent RASopathy gene panel sequencing. Data on 125 individuals with heterozygous LZTR1 variants were collected for characterizing their clinical features and the associated molecular spectrum. In vitro functional assessment was performed on a representative panel of missense variants and small in-frame deletions. ResultsAnalysis revealed heterozygous LZTR1 variants in 6.0% (51/849) of participants, exceeding the general population prevalence. LZTR1-related CaLMs varied in number, displayed sharp or irregular borders, and were generally isolated but occasionally associated with features recurring in RASopathies. In 2 families, CaLMs and schwannomas co-occurred. The molecular spectrum mainly consisted of truncating variants, indicating loss-of-function. These variants substantially overlapped with those occurring in schwannomatosis and recessive NS. Functional characterization showed accelerated protein degradation or mislocalization, and failure to downregulate mitogen-activated protein kinase signaling. ConclusionOur findings expand the phenotypic variability associated with LZTR1 variants, which, in addition to conferring susceptibility to schwannomatosis and causing dominant and recessive NS, occur in individuals with isolated multiple CaLMs.

Is There a Link between Chronic Obstructive Pulmonary Disease and Lung Adenocarcinoma? A Clinico-Pathological and Molecular Study.

Chronic Obstructive Pulmonary Disease (COPD) and lung cancer are strictly related. To date, it is unknown if COPD-associated cancers are different from the tumors of non-COPD patients. The main goal of the study was to compare the morphological/molecular profiles of lung adenocarcinoma (LUAD) samples of COPD, non-COPD/smokers and non-COPD/non-smokers, and to investigate if a genetic instability also characterized non-pathological areas. This study included 110 patients undergoing surgery for a LUAD, divided into three groups: COPD/smoker LUAD (38), non-COPD/smoker LUAD (54) and non-COPD/non-smoker LUAD (18). The tissue samples were systemically evaluated by pathologists and analyzed using a 30-gene Next Generation Sequencing (NGS) panel. In a subset of patients, tissues taken far from the neoplasia were also included. The non-COPD/smoker LUAD were characterized by a higher proliferative index (p = 0.001), while the non-COPD/non-smoker LUAD showed higher percentages of lepidic pattern (p = 0.008), lower necrosis, higher fibrosis, and a significantly lower mutation rate in the KRAS and PIK3CA genes. Interestingly, the same gene mutations were found in pathological and normal areas exclusively in the COPD/smokers and non-COPD/smokers. COPD/smoker LUAD seem to be similar to non-COPD/smoker LUAD, particularly for the genetic background. A less aggressive cancer phenotype was confirmed in non-COPD/non-smokers. The genetic alterations detected in normal lungs from smokers with and without COPD reinforce the importance of screening to detect early neoplastic lesions.

Isolated intraductal carcinoma of the prostate: a clinicopathological and molecular analysis

Objective: To study the clinicopathological features, immunohistochemical phenotypes, molecular changes, differential diagnosis and prognosis of isolated intraductal carcinoma of the prostate (iIDC-P). Methods: Three iIDC-P cases were collected retrospectively from 2016 to 2022 at Ningbo Clinical Pathology Diagnosis Center, Ningbo, China. The clinicopathologic features and immunophenotypic profiles were studied using light microscopy and immunohistochemistry. A targeted next-generation sequencing panel was used to analyze cancer-associated mutations. Follow-up and literature review were also performed. Results: The patients' ages were 61, 67 and 77 years, and their preoperative prostate specific antigen (PSA) levels were 7.99, 7.99 and 4.86 μg/L, respectively. Case 1 and 2 were diagnosed on needle biopsy and radical prostatectomy (RP) specimens, and case 3 was diagnosed on a specimen of transurethral resection of the prostate (TURP). The RP specimen was entirely submitted for histologic examination. In the case 1, iIDC-P was found in one tissue core (involving two ducts) in the biopsy specimen, and in 6 sections (diameter, 0.3-1.1 cm) from the radical prostatectomy specimen, and one section had separate foci of low-grade acinar adenocarcinoma (diameter, 0.05 cm). In the case 2, 6 tissue sections from the biopsy specimens showed iIDC-P, and 13 sections from RP specimen showed iIDC-P (diameter, 0.5-1.6 cm), and the other 3 sections had separate low grade acinar adenocarcinoma (diameter, 0.6 cm). In the case 3, 5 tissue blocks from the TURP specimen showed iIDC-P. The case 1 and 2 showed solid architecture with expansile proliferation of neoplastic cells in native ducts and acini. The case 3 showed dense or loose cribriform pattern, with marked cytological atypia, and frequent mitotic figures. Comedonecrosis was found in solid or dense cribriform glands in the case 2. Immunohistochemically, surrounding basal cells were highlighted using high-molecular-weight cytokeratin (34βE12 and CK5/6) and p63, while P504s was positive in the tumor cells. The tumor cells were also positive for AR and prostate markers (NKX3.1, PSA and PSAP), and negative for GATA3. The iIDC-P and acinar adenocarcinoma both showed weak PTEN expression and no ERG (nuclear) expression. In case 2 and 3, targeted sequencing revealed activated oncogenic driver mutations in MAPK and PI3K pathway genes (KRAS, MTOR and PTEN). In addition, pathogenic mutation in TP53 and FOXA1 mutation were found in the case 2 and 3, respectively. No case demonstrated TMPRSS2::ERG translocation. All cases were microsatellite stable and had lower tumor mutation burdens (range, 2.1-3.1 muts/Mb). The patients showed no biochemical recurrence or metastasis after follow-up of 16-91 months. Conclusions: iIDC-P is a special type of intraductal carcinoma of the prostate and differs from intraductal carcinoma within high-grade prostate cancer. iIDC-P has unique molecular characteristics and may represent as a molecularly unique in situ tumor of prostate cancer.

In Silico Deciphering of the Potential Impact of Variants of Uncertain Significance in Hereditary Colorectal Cancer Syndromes.

Colorectal cancer (CRC) ranks third in terms of cancer incidence worldwide and is responsible for 8% of all deaths globally. Approximately 10% of CRC cases are caused by inherited pathogenic mutations in driver genes involved in pathways that are crucial for CRC tumorigenesis and progression. These hereditary mutations significantly increase the risk of initial benign polyps or adenomas developing into cancer. In recent years, the rapid and accurate sequencing of CRC-specific multigene panels by next-generation sequencing (NGS) technologies has enabled the identification of several recurrent pathogenic variants with established functional consequences. In parallel, rare genetic variants that are not characterized and are, therefore, called variants of uncertain significance (VUSs) have also been detected. The classification of VUSs is a challenging task because each amino acid has specific biochemical properties and uniquely contributes to the structural stability and functional activity of proteins. In this scenario, the ability to computationally predict the effect of a VUS is crucial. In particular, in silico prediction methods can provide useful insights to assess the potential impact of a VUS and support additional clinical evaluation. This approach can further benefit from recent advances in artificial intelligence-based technologies. In this review, we describe the main in silico prediction tools that can be used to evaluate the structural and functional impact of VUSs and provide examples of their application in the analysis of gene variants involved in hereditary CRC syndromes.

Novel and Previously Known Mutations of the KCNV2 Gene Cause Various Variants of the Clinical Course of Cone Dystrophy with Supernormal Rod Response in Children.

Background/Objectives: Cone dystrophy with supernormal rod response (CDSRR) is a rare autosomal recessive retinal disorder characterized by a delayed and markedly decreased photoreceptor response. In this article, we aim to describe the clinical course and associated molecular findings in children with cone dystrophy with supernormal rod response associated with recessive mutations in the KCNV2 gene, which encodes a subunit (Kv8.2) of the voltage-gated potassium channel. Methods: The genetic testing of two patients included the next-generation sequencing of a retinal dystrophy panel and direct Sanger sequencing to confirm KCNV2 gene variants, in addition to an electroretinogram (ERG) and spectral domain optical coherence tomography (SD-OCT). Results: Cone dystrophy with supernormal rod response is associated with identified variants in the KCNV2 gene. The genetic analysis of the first case identified a compound heterozygous mutation in the KCNV2 gene, including a de novo nonsense duplication at cDNA position 1109, which led to the premature termination of the p.Lys371Ter codon in the second extracellular domain of the protein. Two patients showed changes in the full-field electroretinogram, especially in the first case, which demonstrated a close to supernormal total electroretinogram amplitude. This study increased the range of the KCNV2 mutation database, added an unreported de novo substitution pattern to KCNV2 gene variants, and linked it to the evaluated clinical studies. Conclusions: The initial clinical manifestations were varied, but both patients presented with hypermetropia and slight exotropia. The ERG findings are characteristic of KCNV2 mutations, and patients exhibited an increased b-wave latency in DA3.0 ERG (combined rod-cone response).

Clinical, pathologic and molecular findings in 2 Rottweiler littermates with appendicular osteosarcoma

Appendicular osteosarcoma was diagnosed and treated in a pair of littermate Rottweiler dogs, resulting in distinctly different clinical outcomes despite similar therapy within the context of a prospective, randomized clinical trial (NCI-COTC021/022). Histopathology, immunohistochemistry, mRNA sequencing, and targeted DNA hotspot sequencing techniques were applied to both dogs’ tumors to define factors that could underpin their differential response to treatment. We describe the comparison of their clinical, histologic and molecular characteristics, as well as those from a companion cohort of Rottweiler dogs. A pan-cancer genomic sequencing panel conducted in the sibling dogs demonstrated both shared and distinct alterations in several genes implicated in osteosarcoma, including CDKN2B, SETD2, MYC, and PDGFRA, while transcriptional profiling of primary tumor tissue indicated under-expression of key immunological response genes. This report provides new insight into molecular features and potential prognostic biomarkers for canine osteosarcoma.

Performance of a Rapid Digital PCR Test for the Detection of Non-Small Cell Lung Cancer (NSCLC) Variants.

Next-generation sequencing is widely used for comprehensive molecular profiling for many cancers including lung cancer. However, the complex workflows and long turnaround times limit its access and utility. ChromaCode's High Definition PCR Non-Small Cell Lung Cancer Panel (HDPCR™ NSCLC Panel) is a low-cost, rapid turnaround, digital polymerase chain reaction assay that is designed to detect variants in nine NSCLC genes listed in National Comprehensive Cancer Network guidelines. This assay uses TaqMan® probe limiting chemistry and proprietary analysis software to enable multi-target detection within a single-color channel. We compared the performance of the HDPCR™ NSCLC Panel against an in-house, laboratory-developed, targeted next-generation sequencing panel used in the Molecular Diagnostics Laboratory at the University of Minnesota Medical Center to detect biomarkers for NSCLC. The overall accuracy of the HDPCR panel was 99.48% (95% confidence interval 99.01-99.76) with a sensitivity of 95.35% (95% confidence interval 88.52-98.72) and a specificity of 99.69% (95% confidence interval 99.29-99.90). The HDPCR wet lab workflow was 4 h, and the time to generate variant calls from raw data using the ChromaCode Cloud was 2 minutes. We demonstrated that the HDPCR™ NSCLC Panel provides timely, comprehensive, and sensitive mutation detection in NSCLC samples with results in less than 24 h.

Relevance of genetic testing in the gene-targeted trial era: the Rostock Parkinson's disease study.

Estimates of the spectrum and frequency of pathogenic variants in Parkinson's disease (PD) in different populations are currently limited and biased. Furthermore, although therapeutic modification of several genetic targets has reached the clinical trial stage, a major obstacle in conducting these trials is that PD patients are largely unaware of their genetic status and, therefore, cannot be recruited. Expanding the number of investigated PD-related genes and including genes related to disorders with overlapping clinical features in large, well-phenotyped PD patient groups is a prerequisite for capturing the full variant spectrum underlying PD and for stratifying and prioritizing patients for gene-targeted clinical trials. The Rostock Parkinson's disease (ROPAD) study is an observational clinical study aiming to determine the frequency and spectrum of genetic variants contributing to PD in a large international cohort. We investigated variants in 50 genes with either an established relevance for PD or possible phenotypic overlap in a group of 12 580 PD patients from 16 countries [62.3% male; 92.0% White; 27.0% positive family history (FH+), median age at onset (AAO) 59 years] using a next-generation sequencing panel. Altogether, in 1864 (14.8%) ROPAD participants (58.1% male; 91.0% White, 35.5% FH+, median AAO 55 years), a PD-relevant genetic test (PDGT) was positive based on GBA1 risk variants (10.4%) or pathogenic/likely pathogenic variants in LRRK2 (2.9%), PRKN (0.9%), SNCA (0.2%) or PINK1 (0.1%) or a combination of two genetic findings in two genes (∼0.2%). Of note, the adjusted positive PDGT fraction, i.e. the fraction of positive PDGTs per country weighted by the fraction of the population of the world that they represent, was 14.5%. Positive PDGTs were identified in 19.9% of patients with an AAO ≤ 50 years, in 19.5% of patients with FH+ and in 26.9% with an AAO ≤ 50 years and FH+. In comparison to the idiopathic PD group (6846 patients with benign variants), the positive PDGT group had a significantly lower AAO (4 years, P = 9 × 10-34). The probability of a positive PDGT decreased by 3% with every additional AAO year (P = 1 × 10-35). Female patients were 22% more likely to have a positive PDGT (P = 3 × 10-4), and for individuals with FH+ this likelihood was 55% higher (P = 1 × 10-14). About 0.8% of the ROPAD participants had positive genetic testing findings in parkinsonism-, dystonia/dyskinesia- or dementia-related genes. In the emerging era of gene-targeted PD clinical trials, our finding that ∼15% of patients harbour potentially actionable genetic variants offers an important prospect to affected individuals and their families and underlines the need for genetic testing in PD patients. Thus, the insights from the ROPAD study allow for data-driven, differential genetic counselling across the spectrum of different AAOs and family histories and promote a possible policy change in the application of genetic testing as a routine part of patient evaluation and care in PD.

Hereditary breast cancer next-generation sequencing panel evaluation in the south region of Brazil: A novel BRCA2 candidate pathogenic variant is reported.

In this article, we delineate a loosely selected cohort comprising patients with a history of early-onset breast cancer and/or a familial occurrence of cancer. The aim of this study was to gain insights into the presence of breast cancer-related gene variants in a population from a micro-region in southern Brazil, specifically the Metropolitan Region of Curitiba. This area exhibits a highly genetically mixed population, mirroring the general characteristics of the Brazilian people. Comprehensive next-generation sequencing (NGS) multigene panel testing was conducted on 12 patients from the region, utilizing three different library preparation methods. Two pathogenic variants and one candidate pathogenic variant were identified: BRCA2 c.8878C>T, p.Gln2960Ter; CHEK2 c.1100del, p.Thr367Metfs15, and BRCA2 c.3482dup, p.Asp1161Glufs3. BRCA2 c.3482dup, a novel candidate pathogenic variant, previously unpublished, is reported. The prevalence of pathogenic variants in this small cohort is similar to that described in the literature. All different library preparation methods were equally proficient in enabling the detection of these variants.

Clinical application of whole-genome sequencing of solid tumors for precision oncology

Genomic alterations in tumors play a pivotal role in determining their clinical trajectory and responsiveness to treatment. Targeted panel sequencing (TPS) has served as a key clinical tool over the past decade, but advancements in sequencing costs and bioinformatics have now made whole-genome sequencing (WGS) a feasible single-assay approach for almost all cancer genomes in clinical settings. This paper reports on the findings of a prospective, single-center study exploring the real-world clinical utility of WGS (tumor and matched normal tissues) and has two primary objectives: (1) assessing actionability for therapeutic options and (2) providing clarity for clinical questions. Of the 120 patients with various solid cancers who were enrolled, 95 (79%) successfully received genomic reports within a median of 11 working days from sampling to reporting. Analysis of these 95 WGS reports revealed that 72% (68/95) yielded clinically relevant insights, with 69% (55/79) pertaining to therapeutic actionability and 81% (13/16) pertaining to clinical clarity. These benefits include the selection of informed therapeutics and/or active clinical trials based on the identification of driver mutations, tumor mutational burden (TMB) and mutational signatures, pathogenic germline variants that warrant genetic counseling, and information helpful for inferring cancer origin. Our findings highlight the potential of WGS as a comprehensive tool in precision oncology and suggests that it should be integrated into routine clinical practice to provide a complete image of the genomic landscape to enable tailored cancer management.

Incorporating Tumor Genomic Profiling and Circulating Tumor Cell-derived Organoids into Clinical Practice for Gastrointestinal Cancers.

Precision medicine aims to revolutionize healthcare by tailoring treatment regimens. This study aimed to integrate comprehensive tumor genomic profiling (CTGP) by targeted-gene panel sequencing and drug screening by circulating tumor cell-derived organoids (CTOs) into clinical practice for the treatment of gastrointestinal (GI) cancers. Nine patients with various GI cancers underwent CTGP and CTO drug sensitivity testing. CTGP results guided targeted therapy and immunotherapy, while CTO drug sensitivity predicted response to chemotherapy and targeted agents. The drug recommendations from two platforms were correlated with the treatment response to the suggested medications retrospectively. Five patients received therapies aligned with CTGP, including HER2-targeted treatment, immunotherapy, and BRAF/MEK dual inhibition, showing positive responses. CTO drug sensitivity predicted progression under regorafenib (low potential benefit) and good response to chemotherapy with high potential benefit. The combination of CTGP and CTO drug sensitivity may exhibit significant correlation with clinical outcomes during treatment with candidate drugs, demonstrating a sensitivity of 79% and an accuracy of 75%. This encompasses various treatment modalities, such as chemotherapy, targeted therapy, and immunotherapy. The present investigation elucidated the integration of CTGP and CTO drug sensitivity screening into clinical practice in a complementary manner, showcasing a significant correlation between treatment response and testing outcomes. Additional prospective evaluation of these two testing modalities in a large cohort is warranted to confirm whether the inclusion of CTO drug sensitivity screening confers enhanced survival benefits compared to utilizing CTGP alone.

Switching anti-EGFR antibody re-sensitizes head and neck cancer patient following acquired resistance to cetuximab.

Cetuximab induces responses in about 13% of head and neck squamous cell carcinomas (HNSCC). We describe the molecular mechanism of acquired resistance to cetuximab, which could be overcome by switching to a different anti-EGFR antibody. Biopsies were collected at three different time points: before the start of cetuximab (PRE-cetux), at acquired resistance to cetuximab (AR-cetux), and at acquired resistance to duligotuzumab (AR-duligo). Biopsies were analyzed using tumor and normal whole-exome sequencing, RNASeq, and targeted panel sequencing with ultra-deep coverage to generate differential mutation and expression profiles. WES and targeted sequencing analysis identified an EGFR p.G465R extracellular domain mutation in AR-cetux biopsy. Furthermore, RNASeq confirmed the expression of this mutation in the tumor tissue. This mutation prevented the binding of cetuximab to EGFR and was not present in PRE-cetux and AR-duligo biopsies, suggesting a potential mechanism of acquired resistance to cetuximab. Molecular dynamic simulations confirmed that duligotuzumab effectively binds EGFR with a p.G465R mutation. Interestingly, the p.G465R mutation improved the stability of the duligotuzumab-EGFR complex as compared to the wild-type EGFR. This is the first report of an EGFR ECD mutation associated with acquired resistance to cetuximab, posing a need for further validation. We suggest appropriate serial mutational profiling to identify ECD mutations should be considered for select patients with initial cetuximab benefit.

Idiopathic juvenile osteoporosis-a polygenic disorder?

Idiopathic juvenile osteoporosis (IJO) is a rare condition presenting with vertebral and metaphyseal fractures that affects otherwise healthy prepubertal children. Bone mineral density (BMD) measurements are very low. The primary problem appears to be deficient bone formation, with a failure to accrue bone normally during growth. The onset in childhood suggests IJO is a genetic disorder, and a number of reports indicate that some children carry heterozygous pathogenic variants in genes known to be associated with defective osteoblast function and low bone mass, most commonly LRP5 or PLS3. However, a positive family history is unusual in IJO, suggesting the genetic background can be complex. We describe a young man with classical IJO who was investigated with a bone fragility gene panel and whole genome sequencing. The proband was found to carry four variants in three different genes potentially affecting osteoblast function. From his mother he had inherited mutations in ALPL (p.Asn417Ser) and LRP5 (p.Arg1036Gln), and from his father mutations in LRP5 (p.Asp1551Alsfs*13) and activating transcription factor 4 (ATF4) (p.Leu306Ile). His sister had also inherited the LRP5 (p.Asp1551Alsfs*13) from her father, but not the ATF4 mutation. Their spinal BMD z-scores differed substantially (sister -1.6, father -3.2) pointing to the potential importance of the ATF4 mutation. Activating transcription factor 4 acts downstream from RUNX2 and osterix and plays an important role in osteoblast differentiation and function. This case, together with others recently published, supports the view that IJO can result from clustering of mutations in genes related to osteoblast development and function. Novel genes in these pathways may be involved. Our case also emphasizes the value of detailed study of other family members. After a bone biopsy had excluded a mineralization defect due to hypophosphatasia, the proband was treated with zoledronate infusions with good clinical effect.

Exclusive Characteristics of the p.E555K Dominant-Negative Variant in Autosomal Dominant E47 Deficiency

PurposeTranscription factor 3 (TCF3) encodes 2 transcription factors generated by alternative splicing, E12 and E47, which contribute to early lymphocyte differentiation. In humans, autosomal dominant (AD) E47 transcription factor deficiency is an inborn error of immunity characterized by B-cell deficiency and agammaglobulinemia. Only the recurrent de novo p.E555K pathogenic variant has been associated with this disease and acts via a dominant-negative (DN) mechanism. In this study, we describe the first Asian patient with agammaglobulinemia caused by the TCF3 p.E555K variant and provide insights into the structure and function of this variant.MethodsTCF3 variant was identified by inborn errors of immunity-related gene panel sequencing. The variant E555K was characterized by alanine scanning of the E47 basic region and comprehensive mutational analysis focused on position 555.ResultsThe patient was a 25-year-old male with B-cell deficiency, agammaglobulinemia, and mild facial dysmorphic features. We confirmed the diagnosis of AD E47 transcription factor deficiency by identifying a heterozygous missense variant, c.1663 G>A; p.E555K, in TCF3. Alanine scanning of the E47 basic region revealed the structural importance of position 555. Comprehensive mutational analysis focused on position 555 showed that only the glutamate-to-lysine substitution had a strong DN effect. 3D modeling demonstrated that this variant not only abolished hydrogen bonds involved in protein‒DNA interactions, but also inverted the charge on the surface of the E47 protein.ConclusionsOur study reveals the causative mutation hotspot in the TCF3 DN variant and highlights the weak negative selection associated with the TCF3 gene.