Search Results (1,549)

Acyl-CoA dehydrogenase 9 deficiency is considered as a rare neuromuscular syndrome with an autosomal recessive transmission. The ACAD9 protein presents two essential functions, i.e., the limiting step enzyme of the fatty acid β-oxidation pathway and one of the complex’s compounds involved in the respiratory chain complex I assembly. Thus, loss-of-function mutations are known to convey mitochondrial cytopathologies. A patient with a mild and late-onset phenotype, suffering from exercise intolerance and hypertrophic cardiomyopathy, was diagnosed as a compound heterozygote of the ACAD9 gene. The first c.1240C> T p.Arg414Cys variant has been previously reported and is known to be responsible for ACAD9 deficiency. However, the second c.1636G> A p.Val546Met variant has never been described. The goal was to investigate the eventual pathogenicity of this new genetic variant. For this purpose, molecular cloning was generated to express the ACAD9 gene with the V546M variant in a cell line (ACAD9mut) and compared to cells expressing the wild-type ACAD9. Then, the mitochondrial respiration, ATP production, the mitochondrial network, and the oxidative phosphorylation’s composition were investigated to reveal the effects of the V546M variant. While avoiding to affect the amount of the respiratory chain’s complexes, the new ACAD9 variant was entirely responsible for reducing over 50% of the mitochondrial complex I activity. Full article

Background/Objectives: Truncating mutations in PALB2, a critical component of the BRCA1-PALB2-BRCA2 homologous recombination repair complex, are associated with increased risk and aggressiveness of breast cancer. The consequences of PALB2 truncation on the expression, localization, and functional dynamics of the scaffold protein IQGAP1 were investigated in this study based on two cases of truncated PALB2 human breast invasive ductal carcinoma (IDC), specifically, c.1240C>T (p.Arg414*) and c.2257C>T (p.Arg753*). Methods: Using confocal microscopy, we examined co-expression patterns of IQGAP1 with PALB2, PCNA, CK7, and β-tubulin in tumor tissues from both control cancer and PALB2-mutated cases. Results: In PALB2-truncated tumors, IQGAP1 exhibited enhanced peripheral and plasma membrane localization with elevated co-localization levels compared to controls, suggesting altered cytoskeletal organization. PALB2 truncation increased nuclear and cytoplasmic N-terminal PALB2 immunoreactivity, indicating the presence of truncated isoforms disrupting the homologous recombination repair system. Co-expression analyses with PCNA revealed an inverse expression pattern between IQGAP1 and proliferation markers, suggesting S-phase cell cycle-dependent heterogeneity. Furthermore, the loss of IQGAP1 dominance over CK7 and β-tubulin in mutant tumors, along with persistent intercellular spacing, implied a loss of cell–cell cohesion and the acquisition of invasive traits. Conclusions: These data support a model where PALB2 truncation triggers a reorganization of IQGAP1 that disrupts its canonical structural functions and facilitates tumor progression via enhanced motility and impaired cell–cell interaction. IQGAP1 thus serves as both a functional effector and potential biomarker in PALB2-mutated IDC, opening novel paths for diagnosis and targeted therapeutic intervention. Full article

Background/Objectives: The resistance mutations EGFR^{L858R/T790M/C797S} in epidermal growth factor receptor (EGFR) are key factors in the reduced efficacy of Osimertinib. Predicting the inhibitory effects of Osimertinib derivatives against these mutations is crucial for the development of more effective inhibitors. This study aims to predict the inhibitory effects of Osimertinib derivatives against EGFR^{L858R/T790M/C797S} mutations. Methods: Six models were established using heuristic method (HM), random forest (RF), gene expression programming (GEP), gradient boosting decision tree (GBDT), polynomial kernel function support vector machine (SVM), and mixed kernel function SVM (MIX-SVM). The descriptors for these models were selected by the heuristic method or XGBoost. Comprehensive learning particle swarm optimizer was adopted to optimize hyperparameters. Additionally, the internal and external validation were performed by leave-one-out cross-validation ($Q_{LOO}^2$), 5-fold cross validation ($Q_{5-fold}^2$) and concordance correlation coefficient (CCC), $Q_{F1}^2$, and $Q_{F2}^2$. The properties of novel EGFR inhibitors were explored through molecular docking analysis. Results: The model established by MIX-SVM whose kernel function is a convex combination of three regular kernel functions is best: $R^2$ and RMSE for training set and test set are 0.9445, 0.1659 and 0.9490, 0.1814, respectively; $Q_{LOO}^2$, $Q_{5-fold}^2$, CCC, $Q_{F1}^2$, and $Q_{F2}^2$ are 0.9107, 0.8621, 0.9835, 0.9689, and 0.9680. Based on these results, the IC₅₀ values of 162 newly designed compounds were predicted using the HM model, and the top four candidates with the most favorable physicochemical properties were subsequently validated through PEA. Conclusions: The MIX-SVM method will provide useful guidance for the design and screening of novel EGFR^{L858R/T790M/C797S} inhibitors. Full article

Azole resistance in dermatophytes, particularly Trichophyton indotineae, has become a growing global concern. Current antifungal susceptibility testing protocols (EUCAST, CLSI) have limitations in reproducibility and sensitivity. This study aimed to evaluate how medium composition, incubation temperature, and spore concentration influence itraconazole susceptibility testing across various dermatophyte species. Thirty-eight clinical isolates representing Trichophyton, Microsporum, and Epidermophyton species were tested using a microplate laser nephelometry system (MLN). IC₅₀ values for itraconazole were determined in three different media (Sabouraud glucose (SG), RPMI-based (RG), and RG supplemented with casein (RGC)) at 28 °C and 34 °C. Effects of spore concentration on growth dynamics and lag phase were also analyzed. SG medium provided clear phenotypic separation between resistant and sensitive isolates. In contrast, RG and RGC showed overlapping IC₅₀ values. Lower spore concentrations revealed underlying growth differences, which were masked at higher inoculum levels. Temperature and media composition significantly affected IC₅₀ outcomes. Genotypic analysis confirmed resistance-associated Erg11B point mutations and genomic amplifications in T. indotineae, particularly in combination with Erg1 mutations, forming distinct subpopulations. SG medium combined with reduced spore concentrations offered improved differentiation of resistant versus sensitive strains. These findings support the development of more accurate susceptibility testing protocols and highlight the need to establish species-specific ECOFF values for dermatophytes. Full article

Lung adenocarcinoma exhibits a heterogeneous molecular landscape shaped by key oncogenic drivers and tumor suppressor gene alterations. Mutation frequencies vary geographically, influenced by genetic ancestry and environmental factors. However, the molecular profile of lung adenocarcinoma in Bulgarian patients remains largely uncharacterized. We conducted a prospective study of 147 Bulgarian patients with metastatic lung adenocarcinoma, analyzing clinicopathologic features and somatic mutation frequencies using next-generation sequencing. Key mutations and their prevalence were assessed and compared with published data from other populations. The cohort included predominantly male patients (68.0%) with a median age of 67 years. TP53 mutations were most frequent (41.5%), followed by EGFR alterations (19.0%) and KRAS c.34G>T (p.Gly12Cys) (17.0%). Over half of the patients (51.0%) harbored two or more gene mutations. Mutation frequencies aligned closely with European cohorts, exhibiting a lower prevalence of EGFR mutations compared to East Asian populations. This study characterizes the molecular landscape of lung adenocarcinoma in Bulgaria, highlighting the predominance of TP53 and KRAS mutations. The findings emphasize the need for comprehensive molecular profiling to inform targeted therapies and support precision oncology approaches tailored to the Bulgarian population. Further research is needed to validate these results and improve clinical outcomes. Full article

Background: Medullary thyroid cancer (MTC), a neuroendocrine tumor originating from thyroid parafollicular C-cells, presents therapeutic challenges, particularly in advanced stages. While RET proto-oncogene mutations are known drivers, a comprehensive understanding of the broader somatic mutation landscape is needed to identify novel therapeutic targets and improve prognostication. This study leveraged the extensive AACR Project GENIE dataset to characterize MTC genomics. Methods: A retrospective analysis of MTC samples from GENIE examined recurrent somatic mutations, demographic/survival correlations, and copy number variations using targeted sequencing data (significance: p < 0.05). Results: Among 341 samples, RET mutations predominated (75.7%, mostly M918T), followed by HRAS (10.0%) and KRAS (5.6%), with mutual exclusivity between RET and RAS alterations. Recurrent mutations included KMT2D (5.3%), CDH11 (5.3%), ATM (5.0%), and TP53 (4.1%). NOTCH1 mutations were enriched in metastatic cases (p = 0.023). Preliminary associations included sex-linked mutations (BRAF/BRCA1/KIT in females, p = 0.028), and survival (ATM associated with longer survival, p = 0.016; BARD1/BLM/UBR5/MYH11 with shorter survival, p < 0.05), though limited subgroup sizes warrant caution. Conclusions: This large-scale genomic analysis confirms the centrality of RET and RAS pathway alterations in MTC and their mutual exclusivity. The association of NOTCH1 mutations with metastasis suggests a potential role in disease progression. While findings regarding demographic and survival correlations are preliminary, they generate hypotheses for future validation. This study enhances the genomic foundation for understanding MTC and underscores the need for integrated clinico-genomic datasets to refine therapeutic approaches. Full article

This case report describes a novel intronic mutation, CYP21A2:c.738+75C>T (rs1463196531), identified in a 4-year-old male with congenital adrenal insufficiency, and expands the known mutation spectrum associated with this condition. The patient, born full-term to unrelated parents, presented with adrenal failure within the first month of life, characterized by acute adrenal crisis symptoms such as vomiting, dehydration, weight loss, hypotension, and electrolyte imbalances. Hormonal evaluations confirmed primary adrenocortical insufficiency, necessitating ongoing hydrocortisone and fludrocortisone therapy. Using family trio-based amplicon sequencing of the CYP21A2 gene, we identified compound heterozygosity consisting of a full gene deletion and a novel pathogenic intronic mutation. Additionally, analysis of WGS data was performed to rule out pathogenic variants in genes that might lead to a similar phenotype, thereby eliminating the possibility of other genes contributing to the proband’s disease. This case demonstrates the potential of using amplicon sequencing in molecular genetic diagnostic testing to detect rare intronic variants in the CYP21A2 gene in cases of early-onset adrenal failure. It also contributes to a better understanding of the genetic basis of congenital adrenal hyperplasia (CAH), which remains a significant autosomal recessive disorder affecting cortisol and aldosterone production, with an incidence of 1 in 10,000 to 1 in 15,000 globally. Full article

Mutations in the CFTR gene, which cause the autosomal recessive disease cystic fibrosis, can also affect male fertility. The aim of this study was to investigate the spectrum and carrier frequency of common pathogenic CFTR variants among men from the general population, analyze ethnic differences, and assess associations with male fertility indicators. Male volunteers (n = 1895) from six cities in Russia and Belarus were analyzed for the carrier frequencies of 17 pathogenic CFTR variants and two polymorphisms, as well as semen quality and reproductive hormone levels. Heterozygous carriers of six pathogenic CFTR mutations, F508del, G542X, N1303K, 3849+10kbC>T, CFTRdele2,3, and R117C, and two polymorphisms, IVS9-5T and 5T-(12-13) TG, were identified, with cumulative frequencies of 2.06% and 6.65%, respectively. Significant ethnic differences were revealed in the spectrum and carrier frequencies of pathogenic CFTR variants among Slavs, Buryats, and Yakuts. Slavs exhibited a high proportion of heterozygous carriers of CFTR mutations (2.70%), whereas none were detected among Buryats and Yakuts. The highest carrier frequency for the CFTR polymorphism was observed among Slavs (8.35%), followed by Buryats (5.83%) and Yakuts (1.36%). No association was found between the carriers of identified CFTR variants and male fertility indicators. Thus, the spectrum and carrier frequency of genetic CFTR variants are determined by the ethnic composition of the population, providing a basis for ethnicity-specific screening of pathogenic CFTR variants. Full article

CLL is the most prevalent adult leukemia in Western countries, characterized by the accumulation of monoclonal B lymphocytes. Over the past decade, the therapeutic landscape for CLL has undergone significant transformations, primarily due to the introduction of targeted small molecular therapies like BTK inhibitors and BCL-2 inhibitors, that have improved patient outcomes drastically. Despite significant advances, long-term disease management remains challenging for patients with double-refractory CLL, where responses with subsequent therapies are short-lived. Resistance to these therapies can arise through several mechanisms like kinase-altering BTK mutations, alterations in the BCL-2 pathway, and adaptations within the tumor microenvironment, necessitating the exploration of new therapeutic options. This review provides an in-depth overview of the promising novel treatment approaches under investigation in CLL, focusing on advanced cellular therapies (CAR T-cell therapy), T-cell engagers, new monoclonal antibodies, and various next-generation small molecule inhibitors including BTK degraders, PI3K inhibitors, MALT1 inhibitors, c-MYC inhibitors, CDK9 inhibitors, and agents targeting angiogenesis and DNA damage repair. In this review, we will discuss the novel therapeutic targets and agents as well as ongoing trials, emphasizing the potential of these treatments to overcome resistance and meet the unmet needs of patients, particularly those with double-refractory CLL. Full article

Herpes simplex virus 2 (HSV-2) remains a significant cause of morbidity and mortality in immunocompromised individuals, despite the availability of effective antivirals. Infections caused by drug-resistant isolates are an emerging concern among these patients. Understanding evolutionary aspects of HSV-2 resistance is crucial for designing improved therapeutic strategies. Here, we characterized 11 HSV-2 isolates recovered from various body sites of a single immunocompromised patient suffering from a primary HSV-2 infection unresponsive to acyclovir and foscarnet. The isolates were analyzed phenotypically and genotypically (Sanger sequencing of viral thymidine kinase and DNA polymerase genes). Viral clone isolations, deep sequencing, viral growth kinetics, and dual infection competition assays were performed retrospectively to assess viral heterogeneity and fitness. Sanger sequencing identified mixed populations of DNA polymerase mutant variants. Viral clones were plaque-purified and genotyped, revealing 17 DNA polymerase mutations (K533E, A606V, C625R, R628C, A724V, S725G, S729N, I731F, Q732R, M789T/K, Y823C, V842M, R847C, F923L, T934A, and R964H) associated with acyclovir and foscarnet resistance. Deep-sequencing of the DNA polymerase detected drug-resistant variants ranging between 1 and 95%, although the first two isolates had a wild-type DNA polymerase. Some mutants showed reduced fitness, evidenced by (i) the frequency of variants identified by deep-sequencing not correlating with the proportion of mutants found by plaque-purification, (ii) loss of the variants upon passaging in cell culture, or (iii) reduced frequencies in competition assays. This study reveals the rapid evolution of heterogeneous drug-resistant HSV-2 populations under antiviral therapy, highlighting the need for alternative treatment options and resistance surveillance, especially in severe infections. Full article

Efficient co-utilization of glucose and xylose from lignocellulosic biomass remains a critical bottleneck limiting the viability of sustainable biorefineries. While Corynebacterium glutamicum has emerged as a promising industrial host due to its robustness, further improvements in mixed-sugar co-utilization are needed. Here, we demonstrate how a single amino acid substitution can dramatically transform cellular sugar transport capacity. By combining rational strain engineering with continuous adaptive laboratory evolution, we evolved a ptsG-deficient C. glutamicum strain in glucose–xylose mixtures for 600 h under consistent selection pressure. Whole-genome sequencing revealed a remarkable finding: a single point mutation; exchanging proline for alanine in the myo-inositol/proton symporter IolT1 was sufficient to boost glucose uptake by 83% and xylose uptake by 20%, while increasing the overall growth rate by 35%. This mutation, located in a highly conserved domain, likely disrupts an alpha helical structure, thus enhancing transport function. Reverse engineering confirmed that this single change alone reproduces the evolved phenotype, representing the first report of an engineered IolT1 variant in PTS-independent C. glutamicum that features significantly enhanced substrate uptake. These results both provide an immediately applicable engineering target for biorefinery applications and demonstrate the power of evolutionary approaches to identify non-intuitive solutions to complex metabolic engineering challenges. Full article

Hepatocellular carcinoma (HCC) is a major cause of cancer-related mortality worldwide, but its molecular drivers remain underexplored in Latin American populations. This study investigated the prevalence, co-occurrence, and tissue distribution of somatic mutations in the TERT promoter (C228T/C250T) and CTNNB1 exon 3, as well as TERT gene expression, in liver tissues from Brazilian patients. A total of 85 samples (42 HCC, 21 cirrhosis, and 22 hepatitis) were analysed using Sanger sequencing and RT-qPCR. TERT promoter mutations were detected in 47.6% of HCC tissues, including C228T (45.2%) and C250T (2.4%), and were also present in 19% of cirrhotic tissues but absent in hepatitis samples, supporting their emergence in early hepatocarcinogenesis. CTNNB1 exon 3 mutations occurred in 17.2% of HCCs and significantly co-occurred with TERTp mutations (66.7%, p = 0.0485), although the number of CTNNB1-mutated cases was limited. TERT expression was significantly upregulated in HCC tissues regardless of mutation status (p < 0.001). This is the first study to characterise these mutations in Brazilian HCC patients, highlighting the C228T mutation as a promising biomarker for early detection and molecular surveillance in cirrhotic individuals. Despite the genetic admixture of the studied population, the mutational patterns were comparable to those reported in more homogeneous populations, reinforcing the global relevance of these molecular alterations. Full article

Sensenbrenner syndrome, or cranioectodermal dysplasia (CED), is a rare autosomal recessive ciliopathy characterized by craniofacial, skeletal, ectodermal, and renal abnormalities. Ocular involvement, though infrequent, can include retinal dystrophy with early-onset visual impairment. We report a case of a 2-year-old boy with classic clinical features of CED and significant ocular findings. Genetic testing revealed two novel compound heterozygous variants in the WDR19 gene—c.1778G>T and c.3536T>G—expanding the known mutational spectrum associated with this condition. Ophthalmologic evaluation demonstrated bilateral optic nerve hypoplasia, high hyperopia, and severely reduced ERG responses, consistent with global retinal dysfunction. Fundoscopy revealed optic disk pallor, vessel attenuation, and peripheral pigment changes. Multisystem findings included postaxial polydactyly, brachydactyly, short stature, hypotonia, and stage 2 chronic kidney disease. This case highlights the importance of early ophthalmologic screening in suspected CED and underscores the utility of ERG in detecting early retinal involvement. The identification of two previously undescribed WDR19 variants contributes to genotype–phenotype correlation in CED and emphasizes the need for ongoing documentation to guide diagnosis, management, and genetic counseling. Full article

Background: The bone morphogenetic protein (BMP) signaling pathway is essential for lung development. BMP4, a key regulator, binds to type I (BMPR1) and type II (BMPR2) receptors to initiate downstream signaling. While the inactivation of Bmpr1a and Bmpr1b leads to tracheoesophageal fistulae, the role of BMPR2 mutations in lung epithelial development remains unclear. Methods: We generated induced pluripotent stem cells (iPSCs) from a patient carrying a BMPR2 mutation (c.631C>T), and gene-corrected isogenic controls were created using CRISPR/Cas9. These iPSCs were differentiated into lung progenitor cells and subsequently cultured to generate alveolar and airway organoids. The differentiation efficiency and epithelial lineage specification were assessed using immunofluorescence, flow cytometry, and qRT-PCR. Results: BMPR2-mutant iPSCs showed no impairment in forming a definitive or anterior foregut endoderm. However, a significant reduction in lung progenitor cell differentiation was observed. Further, while alveolar epithelial differentiation remained largely unaffected, airway organoids derived from BMPR2-mutant cells exhibited impaired goblet and ciliated cell development, with an increase in basal and club cell markers, indicating skewing toward undifferentiated airway cell populations. Conclusions: BMPR2 dysfunction selectively impairs late-stage lung progenitor specification and disrupts airway epithelial maturation, providing new insights into the developmental impacts of BMPR2 mutations. Full article

The Apolipoprotein L1 (APOL1) innate immunity gene product represents the sole member of the APOL gene family in humans capable of secretion into circulation, thereby mediating the trypanolysis of T. brucei brucei. Gain-of-function variants of the APOL1 gene originated and spread among human population groups to extend APOL1’s protective capacity to include also serum-resistant subspecies, such as T. brucei gambiense (S342G known as APOL1-G1) and T. brucei rhodesiense (N388_Y389del known as APOL1-G2). The biochemical pathways underlying the lytic activity of these evolutionary favored mutations against bloodstream trypanosomes have been elucidated with remarkable precision. However, the intricate molecular mechanisms by which such variants confer an increased susceptibility to renal cellular injury and consequent kidney disease remain incompletely defined. In the absence of a consistent mechanistic explanation for differential kidney injury, we propose pursuing three interrelated avenues of investigation informed by prior epidemiological and mechanistic evidence linking them to APOL1’s cytotoxicity: (1) Molecular evolution of APOL1 haplotypes in human populations, (2) APOL1 splicing and consequent splice isoforms, (3) Interaction of APOL1 with other APOL gene family members, prioritizing APOL3. In the current study, we use reanalysis of population genetics datasets to resolve the haplotype contexts of all protein-altering APOL1 variants, uncovering previously unrecognized variant–haplotype couplings. We further characterize distinct cellular physiological properties among APOL1 splice isoforms, stressing the importance of isoform vB and what can be learned from isoform vC. Finally, a native interaction, and its interface, between APOL1 and APOL3 is reported, and shown to be differentially modulated by G1 and G2. We contend that continuing studies integrating these three interrelated domains will substantially advance mechanistic insights into APOL1 variant-driven renal injury, and leverage the findings to provide a more cohesive framework to guide future research. Full article