Search Results (323)

Background: Hemiplegic migraine (HM) is a rare and severe subtype of migraine with a complex genetic basis. Although pathogenic variants in CACNA1A, ATP1A2, and SCN1A explain some familial cases, a significant proportion of patients remain genetically undiagnosed. Increasing evidence points to an overlap between migraine and cerebral small vessel disease (SVD), implicating vascular dysfunction in HM pathophysiology. Objective: This study aimed to identify rare or novel variants in genes associated with SVD in a cohort of patients clinically diagnosed with HM who tested negative for known familial hemiplegic migraine (FHM) pathogenic variants. Methods: We conducted a case-control association analysis of whole exome sequencing (WES) data from 184 unrelated HM patients. A targeted panel of 34 SVD-related genes was assessed. Variants were prioritised based on rarity (MAF ≤ 0.05), location (exonic/splice site), and predicted pathogenicity using in silico tools. Statistical comparisons to gnomAD’s Non-Finnish European population were made using chi-square tests. Results: Significant variants were identified in several SVD-related genes, including LRP1 (p.Thr4077Arg), COL4A1 (p.Pro54Leu), COL4A2 (p.Glu1123Gly), and TGFBR2 (p.Met148Leu and p.Ala51Pro). The LRP1 variant showed the strongest association (p < 0.001). All key variants demonstrated pathogenicity predictions in multiple computational models, implicating them in vascular dysfunction relevant to migraine mechanisms. Conclusions: This study provides new insights into the genetic architecture of hemiplegic migraine, identifying rare and potentially deleterious variants in SVD-related genes. These findings support the hypothesis that vascular and cellular maintenance pathways contribute to migraine susceptibility and may offer new targets for diagnosis and therapy. Full article

Coxsackievirus B3 (CV-B3) infection causes inflammatory conditions such as viral myocarditis and meningitis, and incidence rates are rising annually. While children are more likely to be affected by severe manifestations, the molecular basis of this age-dependent susceptibility is poorly understood. In this study, we used young Balb/c mice at three developmental stages (7-, 14-, and 30-day-old mice) to investigate CV-B3 pathogenesis. Our findings revealed that 7-day-old mice exhibited substantial infection susceptibility and pathological severity compared to older mice. Critically, an age-dependent analysis showed a progressive decline in the expression of CV-B3-binding Coxsackievirus and Adenovirus Receptor (CAR) splice variants (CAR1 and CAR2) at both the transcriptional and translational levels as the mice matured from 7 to 30 days. These receptor isoforms demonstrated a direct correlation with viral replication efficiency in younger hosts. Concurrently, aging was associated with a rise in non-binding CAR variants (CAR3 and CAR4). During CV-B3 infection, the abundance of CAR1/CAR2 in young mice facilitated accelerated viral proliferation, coupled with the hyperactivation of the NLRP3 inflammasome and the expansion of IL-17-producing γδT cells (γδT17 cells). This cascade triggered excessive production of proinflammatory cytokines (IL-1β, IL-18, and IL-17), culminating in pronounced inflammatory infiltrates within cardiac and cerebral tissues. These findings establish NLRP3 inflammasome dysregulation as a critical determinant of CV-B3-induced tissue damage and provide novel insights into the heightened susceptibility to CV-B infection during early life and its associated severe disease rates. Full article

Background: Canine oral melanoma (COM) is an aggressive and often fatal neoplasm in dogs, with clinical and molecular similarities to human melanoma. Despite its relevance as a comparative oncology model, the molecular mechanisms underlying COM remain poorly understood. This study aimed to characterize gene expression profiles in COM to identify differentially expressed genes (DEGs), potential biomarkers, and therapeutic targets. Methods: In this pilot study, we performed RNA sequencing (RNA-seq) on tumor and healthy oral tissue samples from dogs. Two independent analytical pipelines—Bowtie2-DESeq2 and HISAT-StringTie-Ballgown—were used to ensure robustness in DEG detection. We also conducted pathway enrichment and isoform-level analyses to investigate biological processes and alternative splicing events. Results: Both approaches identified a core set of 929 common DEGs. Key oncogenic pathways, including MAPK/ERK and cell cycle regulation, were significantly affected, with notable upregulation of BRAF, NRAS, CDK4, and MITF (log2FC = 2.86, p < 0.001). The transcription factor SOX10 and the cytokine IL-33, both previously implicated in melanoma progression, were consistently overexpressed. Additionally, NF1, a known RAS pathway inhibitor, was also upregulated. Isoform analysis revealed novel transcript variants, suggesting a complex layer of post-transcriptional regulation in COM. Many DEGs remained uncharacterized, and chromosomal distribution analysis highlighted potential genomic influences. Conclusions: Our findings provide new insights into the molecular landscape of COM, reinforcing its utility as a model for human melanoma. The identification of conserved oncogenic pathways and novel transcript variants opens avenues for further functional studies and the development of targeted therapies in both veterinary and human oncology. Full article

Spondylocostal dysostosis (SCDO) is a group of rare genetic disorders characterized by segmental vertebral defects and rib deformities due to congenital misalignment, fusion, or reduction in the number of ribs. The causes of the disease have been found in seven genes, including DLL3 (SCDO1, OMIM 602768), MESP2 (SCDO2, OMIM 608681), LFNG (SCDO3, OMIM 609813), HES7 (SCDO4, OMIM 608059), TBX6 (SCDO5, OMIM 602427), RIPPLY2 (SCDO6, OMIM 616566), and DLL1 (SCDO7). Among these, SCDO4, characterized by a short trunk, short neck, and mild nonprogressive scoliosis, is a rare form of reported cases. SCDO4 is identified as caused by homozygous or compound heterozygous variants in the HES7 gene (NM_001165967.2; NP_001159439.1). This study reports a novel homozygous HES7 splice variant (c.43-9T>A) detected in an SCDO4 patient by whole-exome sequencing and confirmed by Sanger sequencing. This variant was evaluated as an acceptor loss variant in intron 1 in the HES7 transcript by in silico analysis and was inherited from the patient’s parent. This study also reviews previous reports to provide a comprehensive overview of SCDO and help us to understand the pathogenesis to develop future treatment strategies. Full article

Vaccine-induced thrombotic thrombocytopenia (VITT) is a rare thrombotic disorder first identified in 2021 as a catastrophic syndrome associated with anti-SARS-CoV-2 adenoviral vector (AdV)-vaccine administration. It is characterized by the presence of oligo- or monoclonal anti-PF4 antibodies able to induce in vitro platelet activation in the presence of PF4. In addition to this immune-based pathomechanism, random splicing events of the Adv-vector DNA encoding for SARS-CoV-2 spike protein resulting in the secretion of soluble spike variants have been postulated as a possible pathophysiological mechanism. More recently, some novel clinical-pathological anti-PF4-associated entities also characterized by thrombosis, thrombocytopenia, and VITT-like antibodies but independent from heparin or AdV-vaccine administration have been identified. To date, these VITT-like disorders have been reported following the administration of vaccines different from anti-SARS-CoV-2 AdV-vaccines, like human papillomavirus (HPV) and mRNA-based COVID-19 vaccines, following a bacterial or viral respiratory infection, and in patients with a monoclonal gammopathy of undetermined significance. The purpose of this review is to provide an update on the knowledge on VITT pathogenesis, focusing on recent findings on anti-PF4 antibodies, on a possible genetic predisposition to VITT, on VITT-antibody intracellular activated pathways, on lipid metabolism alterations, and on new VITT-like disorders. Full article

Inherited epidermolysis bullosa (EB) comprises a group of genetic disorders characterized by fragile skin that blisters easily. Targeted therapies for EB necessitate personalized approaches, underscoring the importance of precise diagnostics through genetic analysis and skin biopsy using transmission electron microscopy and/or immunohistochemistry. This study highlights the application of whole-exome sequencing (WES) to identify key pathogenic variants associated with EB. Most identified variants were associated with the recessive form of dystrophic EB, including four novel COL7A1 mutations: p.Leu1488ArgfsTer222, c.7759-3C>G, p.Gln1886Ter, and c.6501+6T>C, as well as recurrent variants p.Lys142Arg and p.Gly2049Glu. Additionally, variants were detected in KRT5 (c.971T>C, p.Val324Ala), associated with EB simplex, and in LAMB3 (c.2500C>T, p.Gln834Ter) in the homozygous state, associated with junctional EB. In silico splice prediction tools suggested disrupted splicing in both cases. One patient received topical gentamicin therapy targeting the nonsense mutation p.Gln1886Ter. These findings underscore the utility of WES in EB diagnostics, broaden the mutation spectrum, and contribute to the understanding of genotype–phenotype correlations in adult patients with EB. Full article

Background: Hippocampal sclerosis (HS) is a hallmark of mesial temporal lobe epilepsy (MTLE). However, genetic studies on MTLE patients with HS (MTLE-HS) remain limited, especially in East Asian populations. This study aimed to identify genetic variants associated with MTLE-HS and elucidate their biological relevance through integrative genomic and transcriptomic analyses. Methods: We conducted a genome-wide association study (GWAS) on 157 Korean epilepsy patients, including 52 MTLE-HS subjects and 105 non-acquired focal epilepsy individuals without HS as controls. The splicing and expression quantitative trait locus (sQTL and eQTL, respectively) effects of significant variants were analyzed using GTEx datasets. Transcriptomic data from the hippocampi of MTLE-HS subjects and an epilepsy mouse model were examined to assess TMEM14A expression. Gene correlation enrichment analysis was performed to investigate potential associations with epilepsy-related phenotypes. Results: The GWAS identified rs6924849, located downstream of TMEM14A, as significantly associated with MTLE-HS. The sQTL analysis revealed that rs6924849 induces abnormal TMEM14A splicing in hippocampal tissue. Transcriptomic analyses showed reduced TMEM14A expression in MTLE-HS hippocampi, while mice with pilocarpine-induced epilepsy exhibited a transient increase in TMEM14A expression during the acute phase post-status epilepticus. Gene correlation enrichment analyses linked TMEM14A to seizure-related phenotypes in both humans and mice. Conclusions: This study identifies rs6924849 as a novel genetic variant associated with MTLE-HS in an East Asian population. The dysfunctional splicing and altered expression of TMEM14A may contribute to the neuronal loss characteristic of HS, as TMEM14A regulates apoptosis. These findings emphasize the potential role of TMEM14A in MTLE-HS pathogenesis from genomic and transcriptomic perspectives. Full article

BQ323636.1 (BQ), a splice variant of NCOR2, is associated with endocrine therapy resistance and poorer prognosis in ER-positive breast cancer. This study investigates the role of BQ in modulating lipid metabolism to support tumor growth. RNA sequencing of BQ-overexpressing breast cancer cells revealed significant enrichment of fatty acid metabolism pathways (hsa01212 and hsa00061; p < 0.05), with ACSL4 identified as a key target. We show that BQ disrupts the NCOR2-PPARγ interaction, leading to ACSL4 upregulation, which enhances fatty acid oxidation (FAO), acetyl-CoA by 1.8-fold, and ATP production by 2.5-fold to fuel tumor proliferation. BQ also upregulates FASN and SCD, increasing lipids. A metabolites study with mass spectrometry indicated that BQ overexpression increases the fatty acid amount from 47.97 nmol/10⁶ cells to 75.18 nmol/10⁶ cells in MCF7 and from 56.19 nmol/10⁶ cells to 95.37 nmol/10⁶ cells in ZR-75. BQ activates NRF2, which mitigates ROS-induced stress, promoting cell survival. Targeting ACSL4 with the inhibitor PRGL493 reduced ATP production and suppressed tumor growth in vitro and in vivo, without inducing apoptosis, suggesting a cytostatic effect. PRGL493 treatment can reduce BQ overexpressing tumors by 40% in the xenograft model. These results highlight BQ can serve as a transcriptional hub driving lipid metabolism via ACSL4 in breast cancer. Our findings suggest that ACSL4 inhibition could be a novel therapeutic strategy to overcome treatment resistance in high-BQ expressing ER-positive breast cancer. Full article

Background/Objectives: Pharmacogenomic screening plays a crucial role in optimizing chemotherapy outcomes and minimizing toxicity. Characterizing the baseline distribution of genetic variants in specific populations is essential to inform the prioritization of drug–gene combinations for clinical implementation. The objective of this study was to investigate the distribution of pharmacogenetic variants in 36 genes related to the fluoropyrimidine (FP) pathway among healthy Omani individuals, forming a foundation for future studies in cancer patients receiving FP-based chemotherapy. Methods: Ninety-eight healthy Omani participants aged ≥18 years were recruited at the Sultan Qaboos Comprehensive Cancer Care and Research Center. Whole-blood samples were collected, and genomic DNA was extracted. Targeted next-generation sequencing was performed using a custom Ion AmpliSeq panel covering coding exons and splice-site regions of 36 genes involved in FP metabolism and response. Results: A total of 999 variants were detected across the 36 genes, with 63.3% being heterozygous. The ABCC4 gene had the highest mutation frequency (76 mutations), while DHFR and SMUG1 had the lowest (<10 mutations). In DPYD, four functionally significant variants were found at frequencies ranging from 1 to 8.2% of the population. Missense mutations were also observed in MTHFR and UGT1A1. Three actionable variants in DPYD and MTHFR, associated with 5-fluorouracil and/or capecitabine response, were identified. Additionally, 27 novel single-nucleotide polymorphisms of unknown clinical significance were detected. Conclusions: This study reveals key pharmacogenetic variants in the Omani population, underscoring the importance of integrating pharmacogenomic testing into routine care to support safer, more personalized chemotherapy in the region. Full article

Alternative splicing enables a single precursor mRNA to generate multiple mRNA isoforms, leading to protein variants with different structures and functions. Abnormal alternative splicing is frequently associated with cancer development and progression. Recent studies have revealed a complex and dynamic interplay between epigenetic modifications and alternative splicing. On the one hand, dysregulated epigenetic changes can alter splicing patterns; on the other hand, splicing events can influence epigenetic landscapes. The reversibility of epigenetic modifications makes epigenetic drugs, both approved and investigational, attractive therapeutic options. This review provides a comprehensive overview of the bidirectional relationship between epigenetic regulation and alternative splicing in cancer. It also highlights emerging therapeutic approaches aimed at correcting splicing abnormalities, with a special focus on drug-based strategies. These include epigenetic inhibitors, antisense oligonucleotides (ASOs), small-molecule compounds, CRISPR–Cas9 genome editing, and the SMaRT (splice-switching molecule) technology. By integrating recent advances in research and therapeutic strategies, this review provides novel insights into the molecular mechanisms of cancer and supports the development of more precise and effective therapies targeting aberrant splicing. Full article

Background: Ectodermal dysplasia (ED) encompasses a heterogeneous group of genetic disorders affecting ectoderm-derived structures such as hair, teeth, nails, and sweat glands. Among these, variants in TSPEAR (Thrombospondin-type laminin G domain and epilepsy-associated repeats) have been implicated in autosomal recessive ED type 14 (OMIM 618180), predominantly manifesting with dental anomalies and hair dysplasia. However, the mutational spectrum of TSPEAR remains incompletely characterized. Methods: Two female siblings (ID#1 and ID#4) were clinically evaluated for ED. Genetic analysis, including next-generation sequencing (NGS) and Sanger validation, was conducted to identify TSPEAR variants. A segregation study confirmed inheritance patterns within the family. Results: Both affected siblings exhibited hallmark features of TSPEAR-related ED14, including oligodontia with dysmorphic, pointed maxillary central incisors. Hair thinning and cutaneous angiomas were predominant in ID#4. Genetic analysis identified two compound heterozygous variants in TSPEAR: c.543-1G>A, a splice-site variant likely to disrupt mRNA processing, and NM_144991.2:c.1251G>C(p.Gln417His), a missense variant with predicted deleterious effects. Segregation analysis confirmed maternal and paternal inheritance of the respective variants. A third sibling, ID#5, was identified as a heterozygous carrier without clinical manifestations. Conclusions: This study contributes to the expanding understanding of TSPEAR-related ED14 by providing novel genotype–phenotype correlations. Full article

Lung adenocarcinoma (LUAD) is a highly heterogeneous tumor and the most prevalent pathological type of lung cancer. The alternative splicing (AS) of mRNA enables the generation of multiple protein products from a single gene. This is a tightly regulated process that significantly contributes to the proteome diversity in eukaryotes. Recent multi-omics studies have delineated the splicing profiles that underline LUAD tumorigenesis from initiation to metastasis. Such progress holds robust promise to facilitate the development of screening strategies and individualized therapies. Perturbed AS fosters the emergence of novel neoantigen resources and disturbances in the immune microenvironment, which allow new investigations into modulatory targets for LUAD immunotherapy. This review presents an update on the landscape of dysregulated splicing events in LUAD and the associated mechanisms and theranostic perspectives with unique insights into AS-based immunotherapy, such as Chimeric Antigen Receptor T cell therapy. These AS variants can be used in conjunction with current therapeutic modules in LUAD, allowing bench to bedside translation to combat this highly malignant cancer. Full article

Stargardt disease (STGD1), the most common retinal dystrophy caused by pathogenic variants of the biallelic ABCA4 gene, results in irreversible vision loss. This cross-sectional case series study analyzes 18 unrelated Stargardt disease (STGD1) patients from southeast China, examining clinical and genetic features. Ophthalmological assessments included BCVA, ophthalmoscopy, fundus photography, and autofluorescence, with ultra-widefield OCT angiography carried out on one patient. Genetic testing uses targeted exome sequencing for eye disease genes. The mean age of onset was 44.3 years for adult onset (6 patients) and 9.6 years for childhood/adolescent onset (12 patients). The mean logMAR visual acuity was 0.96 (right eye) and 0.91 (left eye). Eight novel ABCA4 variants were found, including two nonsense, two frameshift deletions, one copy number variant, one splice-site alternation, and two deep intronic variants. The genotypes are as follows: 77.8% (14/18) biallelic heterozygous, 16.7% (3/18) homozygous, and one patient with three variants. The study underscores STGD1’s phenotypic and genotypic diversity, expands the ABCA4 mutation spectrum, and offers insights into therapeutic strategies. Full article

Background: Osteogenesis imperfecta (OI) is marked by clinical and genetic heterogeneity, and the genotype–phenotype correlation remains not very clear. We conducted a clinical and genetic study in a Chinese OI cohort to determine the spectra of phenotypes and pathogenic variants. Methods: In this study, 298 Chinese families were recruited from 2019 to 2024. Clinical phenotypes including fractures, short stature, skeletal deformities, blue sclera, dentinogenesis imperfecta, and hearing loss were recorded and analyzed. Next-generation sequencing combined with PCR-based techniques was used to detect candidate pathogenic variants. Variant pathogenicity was evaluated via conservation analysis, bioinformatics analysis, and functional studies at the cellular level. In this OI cohort, the spectra of pathogenic variants, clinical phenotypes, and genotype–phenotype correlations were analyzed. Results: Our OI cohort included 71 type I (23.83%), 122 type III (40.94%), 90 type IV (30.20%), and 15 type V (5.03%) probands. The cohort consisted of 196 children (65.77%) and 102 adults (34.23%). For the first time, phenotypic differences between different age groups were confirmed. In total, we identified 231 variants, including 47 novel pathogenic variants. Notable variants include two atypical splicing variants, one small deletion, two small duplications, one gross deletion, and one gross duplication. New genotype–phenotype correlations were observed: patients with SERPINF1 variants had the highest fracture frequency, followed by those with WNT1 variants, compared to patients with other gene variants. Conclusions: We performed the clinical and genetic analysis in a large Chinese OI cohort. The expanded spectra of genetic variants and clinical phenotypes were constructed by identifying 47 novel pathogenic variants and summarizing the skeletal and extra-skeletal manifestations. The current paper will provide important evidence for the precise diagnosis of the disease. Full article

Background: Apolipoprotein C-III (APOC3) plays a crucial role in triglyceride metabolism and is closely associated with cardiovascular disease risk. Elevated APOC3 levels contribute to higher plasma triglycerides and increased risk of atherosclerosis, making APOC3 expression an attractive and logical therapeutic target. Methods: While studying various APOC3 transcript isoforms expressed in hepatoma cell lines (HepG2, Huh7) and healthy liver tissue using publicly available long-read RNA sequencing, we found three novel APOC3 isoforms. These isoforms were validated through RT-PCR and Sanger sequencing. Results: All three novel isoforms are splicing variants of the MANE transcript, APOC3-201. Isoforms 1 and 2 exhibit splicing patterns similar to APOC3-201 from exons 2–4; however, isoform 1 shares its exon 1 splicing pattern with APOC3-203, while isoform 2 features an extended exon 1 that includes exon 1a, the adjacent intronic region, and exon 1b. The third isoform closely resembles APOC3-201, but lacks exon 2, which contains the translation start codon. Remarkably, similar APOC3 splicing patterns and transcript variants were observed in Caco-2 cells, a model of the small intestine, indicating that these isoforms are not liver-specific. Conclusions: This study identifies three novel APOC3 isoforms and highlights their expression in both hepatic and intestinal cell models. Further studies are needed to elucidate the functional roles of these novel isoforms and their contribution to the regulation of APOC3 gene expression. Full article