Search Results (357)

Leaf color mutants are commonly characterized by altered chlorophyll content and aberrant chloroplast development, making them valuable models for investigating photosynthetic mechanisms and chloroplast biogenesis. In this study, an albino mutant was isolated from a population of transgenic maize breeding lines. Genetic analysis indicated that the mutant phenotype is inherited in a Mendelian manner and is controlled by a single nuclear locus. This was supported by a χ² test performed on the T₂ generation, which confirmed a segregation ratio consistent with 3:1 (176:68, χ² = 1.07 < χ²_0.05 = 3.84, p > 0.05). Microscopic examination revealed the absence of normally developed chloroplasts in mutant cells. Further expression analysis of chloroplast genes via Northern blotting and quantitative real-time PCR (qRT-PCR) suggested that the mutation impairs the regulation of plastid-encoded polymerase (PEP)-dependent chloroplast gene expression. Notably, PCR-based co-segregation analysis indicated that the mutant phenotype is associated with the entire inserted vector sequence, rather than a point mutation or a small genomic deletion. In conclusion, this paper reports the isolation and phenotypic characterization of an etiolated mutant from a transgenic maize breeding population, including comparative ultrastructural analysis of chloroplasts, co-segregation validation, and chloroplast gene expression profiling. These results enhance our understanding of the physiological and molecular mechanisms underlying chlorophyll-deficient mutations in plants. Full article

Pathogenic germline variants in the ATM gene are associated with a 20–30% lifetime risk of breast cancer. Crucially, a relevant fraction of loss-of-function variants in breast cancer susceptibility genes disrupts pre-mRNA splicing. We aimed to perform splicing analysis of ATM splice-site variants identified in the large-scale sequencing project BRIDGES (Breast Cancer After Diagnostic Gene Sequencing). To this end, we bioinformatically selected 47 splice-site variants across 17 exons that were genetically engineered into three minigenes and assayed in MCF-7 cells. Aberrant splicing was observed in 38 variants. Of these, 30 variants, including 7 missense, yielded no or negligible expression of the minigene full-length (mgFL) transcript. A total of 69 different transcripts were characterized, 48 of which harboured a premature termination codon. Some variants, such as c.2922-1G>A, generated complex patterns with up to 10 different transcripts. Alternative 3′ or 5′ splice-site usage was the predominant event. Integration of ATM minigene read-outs into the ACMG/AMP (American College of Medical Genetics and Genomics/Association for Molecular Pathology)-based specifications for the ATM gene enabled the classification of 30 ATM variants as pathogenic or likely pathogenic and 9 as likely benign. Overall, splicing assays provide key information for variant interpretation and the clinical management of patients. Full article

Background: Keratoconus (KC) is a progressive corneal ectasia and a leading cause of corneal transplantation in young adults. Once regarded as a biomechanical disorder, KC is now recognized as a complex disease driven by genetic predisposition, epigenetic modulation, and environmental triggers. Advances in genomics and transcriptomics have begun to elucidate the molecular mechanisms underlying corneal thinning and ectasia. Objectives: This review synthesizes two decades of evidence on the genetic and epigenetic architecture of keratoconus, highlights key molecular pathways implicated by these findings, and discusses translational implications for early diagnosis, risk prediction, and novel therapeutic strategies. Methods: A narrative review was conducted of peer-reviewed human, animal, and in vitro studies published from 2000 to 2025, with emphasis on genome-wide association studies (GWAS), sequencing data, methylation profiling, and non-coding RNA analyses. Findings were integrated with functional studies linking genetic variation to molecular and biomechanical phenotypes. Results: Genetic studies consistently implicate loci such as ZNF469, COL5A1, LOX, HGF, FOXO1, and WNT10A, alongside rare variants in Mendelian syndromes (e.g., brittle cornea syndrome, Ehlers–Danlos spectrum). Epigenetic research demonstrates altered DNA methylation, dysregulated microRNAs (e.g., MIR184, miR-143, miR-182), and aberrant lncRNA networks influencing extracellular matrix remodeling, collagen cross-linking, oxidative stress, and inflammatory signaling. Gene–environment interactions, particularly with eye rubbing and atopy, further shape disease expression. Translational progress includes polygenic risk scores, tear-based biomarkers, and early preclinical studies using RNA-based approaches (including siRNA and antisense oligonucleotides targeting matrix-degrading and profibrotic pathways) and proof-of-concept gene-editing strategies demonstrated in corneal cell and ex vivo models. Conclusions: Keratoconus arises from the convergence of inherited genomic risk, epigenetic dysregulation, and environmental stressors. Integrating multi-omic insights into clinical practice holds promise for earlier detection, precision risk stratification, and development of targeted therapies that move beyond biomechanical stabilization to disease modification. Full article

Hereditary polyneuropathies represent a genetically and clinically heterogeneous group of disorders affecting the peripheral nervous system, characterized by progressive motor, sensory, and autonomic impairment. Advances in molecular genetics have identified key causative genes, including PMP22, MPZ, MFN2, TTR, EGR2, and CX32 (GJB1), which are implicated in Charcot–Marie–Tooth disease, Dejerine–Sottas syndrome, and related neuropathies. These conditions display substantial allelic and locus heterogeneity. Pathogenetically, mechanisms involve impaired myelin maintenance, disrupted axonal transport, mitochondrial dysfunction, and aberrant Schwann cell biology. Despite these insights, therapeutic options remain limited, and there is a pressing need to translate genetic findings into effective interventions. This review aims to provide a comprehensive synthesis of current knowledge compiling all known mutations resulting in hereditary polyneuropathies. In addition, it underscores the molecular pathomechanisms of hereditary polyneuropathies and evaluates emerging therapeutic strategies, including adeno-associated virus mediated RNA interference, CRISPR-based gene editing, antisense oligonucleotide therapy, and small-molecule modulators of axonal degeneration. Furthermore, the integration of precision diagnostics, such as next-generation sequencing and functional genomic approaches, is discussed in the context of personalized disease management. Collectively, this review underscores the need for patient-centered approaches in advancing care for individuals with hereditary polyneuropathies. Full article

Type 2 diabetes mellitus (T2D) affects hundreds of millions worldwide, with recent estimates indicating approximately 589 million adults living with diabetes, most with type 2 disease. Beyond classical insulin signaling pathways, increasing evidence implicates altered protein glycosylation in metabolic dysfunction. The solute carrier 35 (SLC35) family of nucleotide sugar transporters mediates the import of activated sugars into the endoplasmic reticulum and Golgi lumen, thereby influencing global glycosylation patterns. Dysregulation of these transporters can perturb glucose homeostasis, insulin responsiveness, and nutrient-sensing pathways through changes in glycosylation flux. In this review, we dissect the molecular mechanisms by which these transporters modulate glucose homeostasis, insulin signaling pathways, protein O-GlcN acylation, and broader glycosylation processes. We integrate findings from human genetic studies, rodent models, and in vitro functional analyses to characterize how altered SLC35 activity is associated with T2D and metabolic syndrome. Four members demonstrate particularly compelling evidence: SLC35B4 modulates hepatic glucose metabolism, SLC35D3 mutations impair dopaminergic signaling and energy balance, and SLC35F3 variants interact with high-carbohydrate intake to increase metabolic-syndrome risk. SLC35A3, though less studied, may influence glycosylation-dependent insulin signaling through its role in N-glycan biosynthesis. Beyond these characterized transporters, this review identifies potential metabolic roles for understudied family members, suggesting broader implications across the entire SLC35 family. We also discuss how such alterations can lead to disrupted hexosamine flux, impaired glycoprotein processing, aberrant cellular signaling, and micronutrient imbalances. Finally, we evaluate the therapeutic potential of targeting SLC35 transporters, outlining both opportunities and challenges in translating these insights into novel T2D treatments. Full article

Background/Objectives: Krabbe disease (KD) is a hereditary lysosomal disorder whose hallmark is progressive demyelination, with variable involvement of the central nervous system. It is caused by pathogenic variants in the GALC gene that disrupt the function of its gene product, the lysosomal enzyme galactosylceramidase. We analyzed two unrelated cases (one early infantile and one adult) with a clinical suspicion of KD. Methods: We used a combination of biochemical techniques (high-performance liquid chromatography–tandem mass spectrometry), NGS (resequencing gene panels), splicing assays, and molecular modeling to identify and analyze the pathogenicity of the variants underlying the disorder. Results: The two probands were compound heterozygotes for disease-causing variants in the GALC gene, encoding the lysosomal hydrolase galactosylceramidase. Three of the variants were novel and caused aberrant splicing, either by exon skipping (c.908+5G>A and c.1034-1G>C) or by inclusion of a cryptic, deep intronic pseudoexon (c.621+772G>C). The fourth variant was a known missense change (c.956A>G, p.(Tyr319Cys)) with conflicting interpretations of pathogenicity in the databases. Conclusions: We demonstrated the pathogenicity of the three novel splicing variants, all with strong impact on galactosylceramidase function. We also concluded that the c.956A>G missense variant is a hypomorph usually underlying the later-onset, milder phenotypes of KD. Our results stress the importance of integrated approaches combining clinical, biochemical, and genetic testing to obtain a definitive diagnosis of lysosomal diseases. Full article

Uterine mesenchymal tumors encompass a diverse and diagnostically challenging group of neoplasms, including smooth muscle tumors, endometrial stromal tumors (ESS), perivascular epithelioid cell tumors (PEComas), inflammatory myofibroblastic tumors (IMTs), uterine tumor resembling ovarian sex cord tumor (UTROSCT), along with many other relatively rare entities. Traditionally classified by histomorphology and immunophenotype, these tumors are now increasingly defined by recurrent genetic alterations that refine diagnosis and elucidate tumorigenesis. For example, leiomyosarcomas display complex genomic instability with frequent TP53, RB1, and ATRX mutations. Low grade-ESS are characterized by JAZF1::SUZ12 and other related fusions, whereas high-grade tumors harbor YWHAE::NUTM2 or ZC3H7B::BCOR fusions, and BCOR internal tandem duplication (ITD) alterations. PEComas frequently contain TSC1 or TSC2 mutations, leading to aberrant activation of the mTOR pathway. Beyond their diagnostic utility, these molecular signatures increasingly inform prognosis and highlight potential therapeutic targets, including CDK4/6 inhibition, PI3K/AKT/mTOR blockade, and immunotherapy. This review summarizes the evolving molecular landscape of uterine mesenchymal tumors, underscoring the value of integrating molecular testing into clinical practice to enhance diagnostic precision and enable personalized management of these rare yet clinically significant neoplasms. Full article

Analysis of coding areas has long been used to study monogenic illnesses, but despite the extensive use of whole-exome sequencing (WES), up to half of suspected cases remain genetically unexplained. Variants outside coding areas can alter splicing, transcript stability, or gene regulation, compromising normal gene activity. These include mutations in noncoding RNAs, promoters, enhancers, deep intronic sequences, and untranslated regions (UTRs). Several well-known disorders have been linked to these mechanisms, including β-thalassemia caused by deep intronic mutations leading to aberrant splicing, familial hypercholesterolemia caused by promoter defects affecting LDLR expression, and inherited retinal diseases driven by noncoding variants influencing retinal gene regulation. These instances show that pathogenic variation is not limited to the exome and can have significant clinical implications. This review summarizes current understanding of noncoding and regulatory variants in monogenic diseases, discusses how they influence diagnosis and therapy, and highlights integrative approaches combining genomic, transcriptomic, and epigenomic data. Multi-layered research has increased diagnostic accuracy and unveiled new therapeutic potentials, although noncoding variations make the connection between genotype and phenotype more complex. Noncoding regions will need to be incorporated into standard diagnostic procedures to convert molecular insights into concrete therapeutic applications in the future. Predictive algorithms, patient-derived model systems, and functional validation testing will all help to simplify this process. Full article

Hemophilia A (HA) is an X-linked recessive bleeding disorder that predominantly affects males but rarely manifests clinically in females. We report an unusual case of a woman with HA carrying a de novo heterozygous F8 variant, skewed X chromosome inactivation (XCI), and mosaic monosomy X without the Turner syndrome phenotype. DNA was extracted from whole blood. After excluding F8 inversions and large rearrangements, Sanger sequencing of coding regions was performed. XCI was assessed by STR analysis of the AR gene. Haplotypes were identified by fragment analysis of three polymorphic sites. Karyotyping was performed using G-banding. A heterozygous missense variant in the F8 gene, c.6545G>A (p.Arg2182His), was detected with allelic imbalance. STR analysis confirmed ~93% skewed XCI. Karyotyping revealed mosaicism: 45,X [7]/46,XX [14]. Neither parent carried the c.6545G>A variant or karyotype aberrations. We suggest that 46,XX cells carried c.6545G/A with preferential inactivation of the normal X chromosome, whereas 45,X0 cells carried the mutant allele only. The limited proportion of active normal X chromosomes led to a mild rather than severe phenotype. This case highlights complex genetic mechanisms underlying HA in females and underscores the importance of comprehensive molecular and cytogenetic testing for accurate diagnosis, clinical management, and genetic counseling. Full article

Background: Adenomyosis and endometriosis are complex, estrogen-dependent gynecological conditions increasingly diagnosed in adolescents. While traditionally considered diseases of reproductive-age women, emerging evidence suggests a possible developmental origin in some cases, with genetic and epigenetic susceptibility playing a central role. Understanding the contribution of hereditary and molecular factors in adolescent-onset forms may offer insights into early pathogenesis, personalized risk stratification and tailored prevention strategies. Objectives: The objectives of this study were to explore the current evidence supporting a genetic contribution to the development of adenomyosis and endometriosis in adolescents and to identify specific genetic variants, molecular pathways and epigenetic mechanisms potentially involved in early-onset disease. Methods: A narrative literature review was conducted using PubMed and Scopus databases up to September 2025. Studies investigating the genetic basis of adenomyosis and endometriosis in adolescents, including familial aggregation, twin studies, GWAS and candidate gene analyses, were included. Results: Evidence from familial clustering and twin studies suggests a significant heritable component in both conditions. Genome-wide association studies have identified susceptibility loci, particularly involving WNT4, VEZT and ESR1, that may be relevant to adolescent-onset disease. Candidate gene studies further highlight the roles of estrogen signalling, inflammatory pathways, extracellular matrix remodelling and emerging epigenetic alterations, including aberrant DNA methylation and chromatin remodelling, which may influence early lesion development. However, most data are derived from adult cohorts, with limited adolescent-specific analyses. Conclusions: Genetic and epigenetic predispositions appear to contribute significantly to the pathogenesis of endometriosis and possibly adenomyosis in adolescents. Further studies targeting early-onset disease are needed to unravel developmental mechanisms and gene–environment interactions unique to this population. Full article

Background/Objectives: Genetic abnormalities are critical for the diagnosis, prognosis, and therapeutic management of myelodysplastic syndromes (MDS). This study aims to evaluate the clinical utility of Multiplex Ligation-dependent Probe Amplification (MLPA) as a rapid and cost-effective method, determining its place alongside Next-Generation Sequencing (NGS) for the initial genetic assessment of patients with MDS. Methods: Bone marrow samples from 68 patients newly diagnosed with MDS were analyzed. Genomic DNA was investigated using the SALSA MLPA P414-C1 MDS probe mix to detect common copy number variations (CNVs). Results: MLPA detected genetic variants in 25 patients (36.8%). The most common finding was a single chromosomal abnormality (26.5%). Multiple pathological findings were observed in only 1.5% of patients, and a JAK2 mutation was observed in 8.8% of the cohort. However, the presence of these aberrations did not show a statistically significant association with overall survival (OS) in the cohort. Patient sex was identified as the only variable that was associated with a marginal level of statistical significance regarding OS, indicating a worse prognosis for males. Conclusions: MLPA is a valuable, rapid, and cost-effective tool for initial genetic screening in low-resource settings. This was highlighted by our finding that sex was the sole significant prognostic factor, while the MLPA-detected variants were not found to be significant. The findings suggest that comprehensive risk stratification aligned with international standards requires more advanced molecular technologies. Full article

Esophageal cancer (EC) is one of the most aggressive cancers of the digestive system, with two main subtypes: esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). Over four decades, the frequencies of EAC and Barrett’s esophagus (BE), the known precursor lesion for EAC, have sharply increased in North America and Europe. This is mainly due to lifestyle and risk factors such as gastroesophageal reflux disease (GERD), obesity, and smoking. BE development to EAC involves numerous molecular modifications, including genetic and epigenetic alterations. Epigenetic changes, such as aberrant DNA methylation, play a critical role in the pathogenesis and progression of BE. This review discusses how non-genetic risk factors contribute to DNA methylation changes driving the transformation from BE to EAC, providing insights into the potential of developing methylation-based biomarkers for early diagnosis, risk stratification, and therapeutic intervention. Full article

Morphoeic basal cell carcinoma (mBCC) has a higher risk of local recurrence than the more indolent nodular (nodBCC) subtype. Little is known about the genetic and molecular makeup of mBCC that determines its invasive behaviour: a comparison of mBCC with nodBCC was carried out. Whole-exome sequencing (WES) of 20 BCC tumours (10 eyelid morphoeic and 10 nodular) underwent driver gene detection using OncodriveFM and MutSigCV, followed by a randomisation analysis procedure. Samples underwent RNA sequencing, gene-set enrichment analysis and candidates verified by RT-PCR. PTCH1, FLNB, and double-knockdown human keratinocyte models were used to validate phenotype and gene expression. Hedgehog pathway analysis of 20 additional BCCs underwent immunostaining verification. Our analysis revealed FLNB as a potential driver with a mutational cluster in FLNB Filamin domain 24 and a 4-fold reduction in expression compared to normal eyelids in mBCC only. FLNB knockdown demonstrated an mBCC phenotype. Aberrant Gli2 dominant hedgehog (Hh) signalling was seen in mBCC on three molecular levels: mutational significance, transcriptome profile, and protein expression. Gli2-dominant Hh overexpression was seen in the tumour plus stroma of eyelid morphoeic but not nodular BCC. FLNB is a potential tumour suppressor, with its loss producing a morphoeic phenotype in vitro. Full article

Gallbladder cancer (GBC), an aggressive malignancy of the biliary tract, is characterized by pronounced geographical variation and a poor prognosis, with a five-year survival rate below 20%. Despite its low global incidence, it ranks as the fifth most prevalent gastrointestinal cancer. The aim of this review is to provide a comprehensive understanding of the molecular mechanisms underpinning GBC progression, with a particular focus on the pivotal role of transcription factors (TFs) in its pathogenesis. This review delineates how aberrant regulation of TFs contributes to tumor initiation, progression, and therapeutic resistance, and to discuss the translational potential of targeting these factors for clinical benefit. Tumor suppressor TFs such as p53 and p16 frequently undergo genetic alterations, including mutations, deletions, or epigenetic silencing, leading to impaired cell cycle control, DNA repair, and apoptosis. Conversely, oncogenic TFs including TCF4, MYBL2, NF-kB, AP-1, Snail, c-MYC, SP1, FOXK1, KLF-5, STAT3 and BIRC7 are often upregulated in GBC, promoting unchecked proliferation, epithelial–mesenchymal transition (EMT), metastasis, and therapeutic resistance. This review aims to bridge current molecular insights with emerging therapeutic approaches, with particular emphasis on innovative interventions such as proteolysis-targeting chimeras (PROTACs), RNA-based therapeutics, CRISPR-driven genome editing, and epigenetic modulators, which collectively represent promising strategies for achieving more effective and personalized treatment outcomes in patients with GBC. Full article

The process of aging is fundamentally driven by genomic instability and the accumulation of DNA damage, which progressively impair cellular and tissue function. In order to counteract these challenges, cells rely on the DNA damage response (DDR), a multilayered signaling and repair network that preserves genomic integrity and sustains homeostasis. Within this framework, nucleases and helicases have pivotal and complementary roles by remodeling aberrant DNA structures, generating accessible repair intermediates, and determining whether a cell achieves faithful repair, undergoes apoptosis, or enters senescence. Defects in these enzymes are exemplified in human progeroid syndromes, where inherited mutations lead to premature aging phenotypes. This phenomenon is also replicated in genetically engineered mouse models that exhibit tissue degeneration, stem cell exhaustion, and metabolic dysfunction. Beyond their canonical repair functions, helicases and nucleases also interface with the epigenome, as DNA damage-induced chromatin remodeling alters enzyme accessibility, disrupts transcriptional regulation, and drives progressive epigenetic drift and chronic inflammatory signaling. Moreover, their dysfunction accelerates the exhaustion of adult stem cell populations, such as hematopoietic, neural, and mesenchymal stem cells. As a result, tissue regeneration is undermined, establishing a self-perpetuating cycle of senescence, impaired repair, and organismal aging. Current research is focused on developing therapeutic strategies that target the DDR–aging axis on several fronts: by directly modulating repair pathways, by regulating the downstream consequences of senescence, or by preventing DNA damage from accumulating upstream. Taken together, evidence from human disease, animal models, molecular studies, and pharmacological interventions demonstrates that nucleases and helicases are not only essential for genome maintenance but also decisive in shaping aging trajectories. This provides valuable knowledge into how molecular repair pathways influence organismal longevity and age-related diseases. Full article