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Background Germline TP53 gene variants are intricately linked to Li-Fraumeni syndrome, a rare and aggressive hereditary cancer syndrome. This study investigated the frequency and spectrum of TP53 pathogenic variants associated with Li-Fraumeni syndrome in a large cohort of mainly breast cancer patients from Russia. Methods The study analyzed 3,455 genomic DNA samples from cancer patients using next-generation sequencing panels and whole-genome sequencing. Clinically significant TP53 variants were identified and validated using Sanger sequencing. The clinical and family history characteristics of patients with TP53 variants were analyzed. Results The analysis identified 13 (0.4%) individuals with clinically significant germline TP53 variants, all of whom were females with either unilateral breast cancer or breast cancer as part of multiple primary malignant neoplasms. The average age of breast cancer manifestation was 39.9 years, with a median of 36 years. Only 38.5% of the TP53 mutation carriers met the modified Chompret criteria for TP53 testing. Conclusions The findings underscore the necessity of thorough phenotype and family history analysis in genetic counseling to effectively diagnose LFS, and emphasize the importance of identifying TP53 variant carriers for developing treatment strategies, prognosis, and monitoring, as well as for identifying high-risk family members. The study also highlights that the current guidelines fail to identify over half of the TP53 mutation carriers, suggesting the need for a more comprehensive approach to genetic testing in suspected hereditary cancer cases. Keywords: TP53, NGS, Li-Fraumeni syndrome, Germline mutations, Author(s): Anastasiia Danishevich[sup.1], Daria Fedorova[sup.1], Natalia Bodunova[sup.1], Maria Makarova[sup.2,3], Maria Byakhova[sup.4], Anna Semenova[sup.4], Vsevolod Galkin[sup.4], Maria Litvinova[sup.1,5], Sergey Nikolaev[sup.1], Irina Efimova[sup.6], Pavel Osinin[sup.1], Tatyana Lisitsa[sup.7,8], Anastasiya Khakhina[sup.7], German Shipulin[sup.7], Tatiana [...]

The spiny mouse (Acomys species) is capable of scarless wound regeneration through largely yet unknown mechanisms. To investigate whether this capacity is related to peculiarities of the hemostatic system, we studied the blood of Acomys cahirinus in comparison to Mus musculus (Balb/c) to reveal differences in blood composition and clotting in both males and females. In response to surgical manipulations, blood clots formed in wounds of Acomys comprised a stronger hemostatic seal with reduced surgical bleeding in comparison with Balb/c. Acomys demonstrated notably shorter tail bleeding times and elevated clottable fibrinogen levels. Histological analysis revealed that clots from Acomys blood had densely packed fibrin-rich clots with pronounced fibrin segregation from erythrocytes. Acomys exhibited superior plasma clot stiffness as revealed with thromboelastography. The latter two characteristics are likely due to hyperfibrinogenemia. Light transmission platelet aggregometry demonstrated that ADP-induced platelet aggregates in Acomys males are stable, unlike the aggregates formed in the plasma of Balb/c undergoing progressive disaggregation over time. There were no apparent distinctions in platelet contractility and baseline expression of phosphatidylserine. Hematological profiling revealed a reduced erythrocytes count but increased mean corpuscular volume and hemoglobin content in Acomys. These results demonstrate the distinctive hemostatic potential of Acomys cahirinus, which may contribute to their remarkable regenerative capacity. [ABSTRACT FROM AUTHOR]

Tay-Sachs disease (TSD) is a rare genetic disorder with diverse clinical manifestations, often leading to underdiagnosis due to symptom similarities with other neurological conditions. In this study, we aimed to identify the genetic mutations underlying late-onset TSD in a 27-year-old patient with progressive neurological symptoms. Whole-exome sequencing revealed two hexA gene mutations associated with TSD: a previously known variant, c.805G > A (p.Gly269Ser), and a novel splice-site mutation, c.346 + 2dupT. Through clinical assessments, genetic analysis, and functional investigations—including RNA sequencing and enzymatic activity assays—we confirmed the pathogenicity of the novel mutation. Our findings highlight the efficacy of advanced genomic technologies in diagnosing intricate genetic disorders and emphasize the significance of functional validation to confirm the effects of mutations. Identifying compound heterozygous mutations in the hexA gene also provides insight into Mendelian inheritance patterns. This case highlights the diagnostic challenges posed by overlapping clinical phenotypes and emphasizes the need for increased genetic awareness among clinicians. Accurate diagnosis of TSD has significant implications for patients and their families, allowing for informed genetic counseling and guiding clinical management decisions. While current treatment options are limited, timely and accurate diagnosis holds promise for future research and therapeutic interventions. This study highlights the value of a multidisciplinary approach in exploring the molecular basis of complex genetic diseases and informing clinical decisions. [ABSTRACT FROM AUTHOR]

A comprehensive understanding of intercellular and cell–matrix interactions is essential for advancing our knowledge of cell biology. Existing techniques, such as fluorescence microscopy and electron microscopy, face limitations in resolution and sample preparation. Supravital lanthanoid staining provides new opportunities for detailed visualization of cellular metabolism and intercellular interactions. This study aims to describe the structure, elemental chemical, and probable origin of zones of extreme lanthanoid (neodymium) accumulation that form during preparation for scanning electron microscopy (SEM) analysis in corneal fibroblasts filopodia. The results identified three morphological patterns of neodymium staining in fibroblast filopodia, each exhibiting asymmetric staining within a thin, sharp, and extremely bright barrier zone, located perpendicular to the filopodia axis. Semi-quantitative chemical analyses showed neodymium-labeled non-linear phosphorus distribution within filopodia, potentially indicating varying phosphate anion concentrations and extreme phosphate accumulation at a physical or physicochemical barrier. Phosphorus zones labeled with neodymium did not correspond to mitochondrial clusters. During apoptosis, the number of filopodia with extreme and asymmetric phosphorus accumulation increases. Supravital lanthanoid staining coupled with SEM allows detailed visualization of intercellular and cell–matrix interactions with high contrast and resolution. These results enhance our understanding of phosphate anion accumulation and transfer mechanisms in cells under normal conditions and during apoptosis. [ABSTRACT FROM AUTHOR]

Myelodysplastic syndrome (MDS) is a clonal disease derived from hematopoietic stem cells, characterized by ineffective hematopoiesis (resulting in peripheral blood cytopenia) and an increased risk of transformation into acute myeloid leukemia. MDS is caused by a complex combination of genetic mutations resulting in a heterogeneous genotype. Genetic studies have identified a set of aberrations that play a central role in the pathogenesis of MDS. In this article, we present a clinical case of MDS transformation into acute myeloid leukemia in the context of two cell lines exhibiting morphological, immunophenotypic, and dysmyelopoiesis markers and the presence of two heterozygous mutations in the TET2 gene. [ABSTRACT FROM AUTHOR]

The extraocular muscles (EOMs) possess unique characteristics that set them apart from other skeletal muscles. These muscles, responsible for eye movements, exhibit remarkable resistance to various muscular dystrophies and aging, presenting a significant contrast to the vulnerability of skeletal muscles to these conditions. In this review, we delve into the cellular and molecular underpinnings of the distinct properties of EOMs. We explore their structural complexity, highlighting differences in fiber types, innervation patterns, and developmental origins. Notably, EOM fibers express a diverse array of myosin heavy-chain isoforms, retaining embryonic forms into adulthood. Moreover, their motor innervation is characterized by a high ratio of nerve fibers to muscle fibers and the presence of unique neuromuscular junctions. These features contribute to the specialized functions of EOMs, including rapid and precise eye movements. Understanding the mechanisms behind the resilience of EOMs to disease and aging may offer insights into potential therapeutic strategies for treating muscular dystrophies and myopathies affecting other skeletal muscles. [ABSTRACT FROM AUTHOR]

Simple Summary: This study addresses the global healthcare challenge of cancer by investigating hereditary cancer syndromes (HCS) and their genetic underpinnings. Using a multigene hereditary cancer panel, we examined Russian patients with suspected HCS, revealing that 21.6% had pathogenic or likely pathogenic genetic variants. Predominant mutations were found in BRCA1/BRCA2, CHEK2, and ATM genes, and we identified 16 previously undescribed variants in MUTYH, GALNT12, MSH2, MLH1, MLH3, EPCAM, and POLE genes. Our findings underscore the importance of comprehensive genetic testing for personalized cancer prevention and treatment. This research contributes essential genetic insights, particularly in regions like Russia where epidemiological data are limited, establishing the way for improved understanding and management of hereditary cancer syndromes. Cancer is a major global public health challenge, affecting both quality of life and mortality. Recent advances in genetic research have uncovered hereditary cancer syndromes (HCS) that predispose individuals to malignant neoplasms. While traditional single-gene testing has focused on high-penetrance genes, the past decade has seen a shift toward multigene panels, which facilitate the analysis of multiple genes associated with specific HCS. This approach reveals variants in less-studied gene regions and improves our understanding of cancer predisposition. In a study composed of Russian patients with clinical signs of HCS, we used a multigene hereditary cancer panel and revealed 21.6% individuals with pathogenic or likely pathogenic genetic variants. BRCA1/BRCA2 mutations predominated, followed by the CHEK2 and ATM variants. Of note, 16 previously undescribed variants were identified in the MUTYH, GALNT12, MSH2, MLH1, MLH3, EPCAM, and POLE genes. The implications of the study extend to personalized cancer prevention and treatment strategies, especially in populations lacking extensive epidemiological data, such as Russia. Overall, our research provides valuable genetic insights that give the way for further investigation and advances in the understanding and management of hereditary cancer syndromes. [ABSTRACT FROM AUTHOR]