BACKGROUND:Brugada syndrome has been reported in myotonic dystrophy type 1, whereas its association with myotonic dystrophy type 2 (DM2) remains largely unexplored. CASE SUMMARY:We report a patient with genetically confirmed DM2 who presented with an electrocardiogram showing a Brugada type-2 ECG pattern. Sodium-channel blocker testing unmasked a diagnostic type 1 Brugada pattern. Genetic analysis excluded SCN5A variants and identified a rare heterozygous ANK2 missense variant, a gene involved in cardiac electrical stability. CONCLUSION:This case expands the spectrum of Brugada phenotypes to DM2 and highlights the importance of not underestimating suspicious Brugada-like ECG findings in patients with muscular dystrophies.

Repeat-expansion disorders (REDs) are a mechanistically and clinically well-defined subgroup of rare diseases caused by the expansion of short tandem repeats (STRs). These expansions can exceed several kilobases and show complex features, such as noncanonical secondary structures, somatic instability, repeat interruptions and allele-specific methylation. These characteristics are highly relevant for understanding disease mechanisms, clinical variability, prognosis and potentially therapeutic decision-making, but cannot be fully resolved using traditional diagnostic methods or short-read sequencing technologies. By contrast, long-read sequencing (LRS) enables accurate investigation of STR complexity in a single assay, facilitates the discovery of new pathogenic repeat expansions and drives advances in diagnostics, clinical and basic research, which may allow for better patient stratification in future clinical trials. This Perspective discusses recent LRS-driven discoveries, methodological and bioinformatic advances, and emerging diagnostic applications to illustrate the potential of LRS in reshaping both research and clinical practice.

Abstract Introduction. Myotonic dystrophy type 2 (DM2) is an autosomal dominant disorder caused by (CCTG)n repeat expansions in intron 1 of the CNBP gene. Recent evidence from long-read sequencing suggests these expansions may be more complex than previously recognized. Aim. To comprehensively characterize the composition, intergenerational dynamics, and clinical impact of novel (TCTG)n motifs within the CNBP expanded alleles in a large DM2 cohort. Methods. We analyzed 100 genetically confirmed DM2 individuals (45 sporadic, 55 familial). The presence of (TCTG)n blocks was detected using an optimized quadruplet-repeat primed PCR (QP-PCR) assay coupled with Sanger sequencing. In a subset of nine patients, Cas9-mediated enrichment followed by Nanopore Long-Read Sequencing (LRS) provided nucleotide-level resolution of the expanded alleles. Haplotype analysis was performed using STR markers. Results. We identified (TCTG)n blocks at the 3′ end of the expansion in 88% of patients. This refined assay corrected nine initial false-negative diagnoses from standard testing. LRS analysis confirmed the composition and revealed the dynamics of the (TCTG)n tract in familial transmission, showing a tendency for contraction and, in one case, complete loss. Genotype–phenotype correlation analysis indicated that the presence of the (TCTG)n motif acts as a disease modifier, significantly influencing the age of onset. Conclusion. The detailed characterization of the CNBP expansion reveals the novel (TCTG)n component that is integral to the DM2 genotype. Understanding its composition and dynamics enhances diagnostic accuracy and provides a new framework for genetic counselling, prognostic stratification and future personalized therapies. .

ABSTRACT The broader application of long-read sequencing (LRS) for repeat expansion characterization in myotonic dystrophy type 2 (DM2) and other repeat expansion disorders (REDs) remains limited by the lack of systematic validation and benchmarking of sequencing results and bioinformatic workflows. Here, we performed an orthogonal cross-platform validation of previously generated Oxford Nanopore Technologies (ONT) data by sequencing the same DNA samples with Pacific Biosciences (PacBio) HiFi following amplification-free targeted enrichment in a cohort of 8 DM2 patients. Despite substantial differences in sequencing chemistry and coverage, the two platforms showed high concordance in repeat size estimation, somatic mosaicism, and repeat architecture. This validation confirmed the presence of the (TCTG)n motif and enabled the identification of a previously unreported (CCCG)n motif at the 3′ end of expanded alleles, further highlighting the structural complexity of the CNBP expansion. Through this analysis, we also established a bioinformatic workflow that improved ONT-based repeat characterization, addressing limitations in motif resolution and enabling more accurate analysis of CNBP expansions. Overall, this study provides a validated framework for LRS-based CNBP repeat analysis, supporting the integration of these technologies into routine molecular investigation for DM2 and other REDs.

Extracellular vesicles (EVs) have emerged as fundamental pillars of intercellular communication, acting as primary mediators of the bidirectional biochemical crosstalk within the integrated bone-muscle unit. This review provides a comprehensive synthesis of EV-mediated signaling across the bone-muscle axis, offering a side-by-side mapping of vesicular biogenesis, cargo composition, and functional roles in both tissues. Under physiological conditions, skeletal muscle- and bone-derived EVs orchestrate tissue homeostasis, adaptations to physical exercise, myogenesis, and bone remodeling by transferring unique molecular cargos of proteins and specific microRNAs. However, aging induces a profound remodeling of the EV secretome toward a senescent profile characterized by harmful vesicular factors. This dysfunctional vesicular signaling impairs both muscle regeneration and osteogenesis, directly contributing to the pathogenesis of interconnected age-related disorders like sarcopenia, osteoporosis, and osteosarcopenia. Concurrently, circulating EVs represent valuable, minimally invasive biomarkers for early diagnosis. On the therapeutic front, this review critically evaluates emerging EV-based approaches, utilizing mesenchymal stem cell-derived, bioengineered, or biomaterial-incorporated EVs, offering promising, low-immunogenic alternatives to cell transplantation to enhance musculoskeletal tissue repair and restore bone-muscle homeostasis. Despite persisting technical challenges regarding large-scale production and standardization, targeting or leveraging EV-mediated communication represents one of the most innovative and revolutionary strategies to counteract age-related musculoskeletal decline. By unifying physiological mechanisms, age-related molecular reprogramming, and therapeutic engineering across both muscle and bone into a single narrative, this review provides a comprehensive framework to guide future research and clinical translation in musculoskeletal health.

Background/Objectives: Cellular aging represents a crucial element in the progression of musculoskeletal diseases, contributing to muscle atrophy, functional decline, and alterations in bone turnover, which promote fragility fractures. However, knowledge about expression patterns of factors potentially involved in aging and senescence at the tissue level remains limited. Our pilot study aimed to characterize the expression profile of cell cycle regulators, factors released by aged cells, and sirtuin 1 (SIRT1) in the muscle tissue of 26 elderly patients undergoing hip arthroplasty, including 13 with low-energy fracture and 13 with osteoarthritis (OA). Methods: The mRNA expression levels of cyclin-dependent kinase inhibitor 1A (CDKN1A), cyclin-dependent kinase inhibitor 1B (CDKN1B), cyclin-dependent kinase inhibitor 2A (CDKN2A), p53, tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interleukin-15 (IL-15), chemokine (C-C motif) ligand 2 (CCL2), chemokine (C-C motif) ligand 3 (CCL3), growth differentiation factor 15 (GDF15), and SIRT1 were evaluated in muscle tissue by qRT-PCR. In addition, immunohistochemistry and Western blotting analysis were conducted to measure the protein levels of SIRT1. Results: A marked muscle atrophy was observed in fractured patients compared to the OA group, in association with an up-regulation of cell cycle regulators and factors released by the aged cells. The expression of matrix metallopeptidase 3 (MMP3), plasminogen activator inhibitor 1 (PAI-1), and fas cell surface death receptor (FAS) was also investigated, although no significant differences were observed between the two experimental groups. Notably, SIRT1 expression was significantly higher in OA patients, confirming its role in maintaining muscle health during aging. Conclusions: Further studies will be needed to clarify the role of SIRT1 in the senescence characteristic of age-related musculoskeletal disorders, counteracting the muscle atrophy that predisposes to fragility fractures.

Hereditary-Motor-Neuropathies (dHMNs) are clinically and genetically heterogeneous neurological disorders characterized by degeneration of peripheral motoneurons. We previously identified two sigma-1 receptor (Sigma-1R) variants (p.E138Q; p.E150K) in dHMN Italian patients that behave as "loss-of-function" mutations in neuroblastoma cell lines. Here, we characterize the functional effects of Sigma-1R mutation in primary fibroblasts from homozygous patients bearing the E150K mutation, and matched controls, by performing biochemical, gene expression, immunofluorescence and Ca2+ imaging analysis. Our results show that Sigma-1R expression and distribution is significantly altered in patient fibroblasts. Moreover, patient cells present a general derangement of cell homeostasis as revealed by impairment of global Ca2+ dynamics, disorganization of the ER-mitochondria tethers, enhancement of the autophago-lysosomal pathway and blunting of mitochondrial aerobic metabolism compared to controls. These findings highlight the crucial role of Sigma-1R in the maintenance of cell and protein homeostasis, inter-organelle communication and intracellular Ca2+ signalling, supporting the notion that Sigma-1R is protective for motor neuron activity and its down-regulation and/or loss-of-function, as in the case of the E150K mutation, might play the key role in the neuronal degeneration in dHMN patients.

The aging of the world population is closely associated with an increased prevalence of musculoskeletal disorders, such as osteoporosis, sarcopenia, and osteoarthritis, due to common genetic, endocrine, and mechanical risk factors. These conditions are characterized by degeneration of bone, muscle, and cartilage tissue, resulting in an increased risk of fractures and reduced mobility. Importantly, a crucial role in the pathophysiology of these diseases has been proposed for cellular senescence, a state of irreversible cell cycle arrest induced by factors such as DNA damage, telomere shortening, and mitochondrial dysfunction. In addition, senescent cells secrete pro-inflammatory molecules, called senescence-associated secretory phenotype (SASP), which can alter tissue homeostasis and promote disease progression. Undoubtedly, targeting senescent cells and their secretory profiles could promote the development of integrated strategies, including regular exercise and a balanced diet or the use of senolytics and senomorphs, to improve the quality of life of the aging population. Therefore, our review aimed to highlight the role of cellular senescence in age-related musculoskeletal diseases, summarizing the main underlying mechanisms and potential anti-senescence strategies for the treatment of osteoporosis, sarcopenia, and osteoarthritis.

We report on genetic and environmental modulation of social cognition abilities and brain volume correlates in two monozygotic twins (Twin1 and Twin2) with genetically confirmed myotonic dystrophy-type1 who grew up in different environmental settings. They both underwent neuropsychological assessment (i.e., Intelligent Quotient [IQ], theory of mind, emotion recognition tests), and MRI scanning to evaluate regional brain volumetrics compared to 10 gender and sex-matched healthy controls. Against a normal IQ level in both patients, Twin1 was more impaired in emotional processing and Twin2 in cognitive aspects of social cognition. Both patients showed grey matter (GM) atrophy in Brodmann Areas 23/31 (BA23/31) and BA7 bilaterally, while Twin2 showed additional GM loss in right BA46. Both patients showed a similar pattern of white matter atrophy involving the thalamus, basal ganglia, and uncinate fasciculus. White matter atrophy appeared to be mostly driven by genetics, while grey matter volumes appeared associated with different impairments in social cognition and possibly modulated by environment.

Osteoporosis, a prevalent age-related condition, is characterized by decreased in bone mass and bone quality. Among the pathogenetic mechanisms, cellular senescence has been suggested to induce inflammation and affect bone cell function, contributing to bone fragility. In this context, sirtuin 1 (SIRT1), an NAD+-dependent deacetylase, emerges as a central regulator of musculoskeletal health, influencing osteoblastic differentiation, suppressing osteoclastic activity and maintaining bone mass by the deacetylation of critical targets. Interestingly, a close association was found between an elevated senescence-associated secretory phenotype and aged bone cells, confirming a role for senescence in bone aging. The aim of our minireview is to highlight cellular senescence as a key factor in osteoporosis, focusing on the central role of SIRT1 and exploring potential strategies to modulate its activity, including diet, exercise and pharmacological interventions. In conclusion, enhancing SIRT1 activity represents a potential therapeutic approach for age-related bone disorders, offering interesting perspectives for future research and therapeutic development. KEY WORDS: SIRT1, osteoporosis aging senescence bone cells, diet, exercise, pharmacological interventions.

Myotonic dystrophy type 1 (DM1) is an autosomal dominant multisystemic disease caused by a CTG repeat expansion in the 3′-untranslated region (UTR) of DMPK gene. DM1 alleles containing non-CTG variant repeats (VRs) have been described, with uncertain molecular and clinical consequences. The expanded trinucleotide array is flanked by two CpG islands, and the presence of VRs could confer an additional level of epigenetic variability. This study aims to investigate the association between VR-containing DMPK alleles, parental inheritance and methylation pattern of the DM1 locus. The DM1 mutation has been characterized in 20 patients using a combination of SR-PCR, TP-PCR, modified TP-PCR and LR-PCR. Non-CTG motifs have been confirmed by Sanger sequencing. The methylation pattern of the DM1 locus was determined by bisulfite pyrosequencing. We characterized 7 patients with VRs within the CTG tract at 5′ end and 13 patients carrying non-CTG sequences at 3′ end of the DM1 expansion. DMPK alleles with VRs at 5’ end or 3’ end were invariably unmethylated upstream of the CTG expansion. Interestingly, DM1 patients with VRs at the 3′ end showed higher methylation levels in the downstream island of the CTG repeat tract, preferentially when the disease allele was maternally inherited. Our results suggest a potential correlation between VRs, parental origin of the mutation and methylation pattern of the DMPK expanded alleles. A differential CpG methylation status could play a role in the phenotypic variability of DM1 patients, representing a potentially useful diagnostic tool.

The Vitamin D Receptor (VDR) mediates the actions of 1,25-Dihydroxvitamin D3 (1,25(OH)2D3), which has important roles in bone homeostasis, growth/differentiation of cells, immune functions, and reduction of inflammation. Emerging evidences suggest that epigenetic modifications of the VDR gene, particularly DNA methylation, may contribute to the onset and progression of many human disorders. This review aims to summarize the available information on the role of VDR methylation signatures in different pathological contexts, including autoimmune diseases, infectious diseases, cancer, and others. The reversible nature of DNA methylation could enable the development of therapeutic strategies, offering new avenues for the management of these worldwide diseases.

The vitamin D receptor (VDR) regulates bone development and calcium homeostasis, suggesting a central role in musculoskeletal diseases such as osteoporosis (OP). Several studies have examined the contribution of VDR polymorphisms and epigenetic signatures in bone metabolism and OP risk, with sometimes inconclusive results. Our study aimed to explore the association between genetic variability, expression and the methylation pattern of VDR with the risk of OP in a cohort of Caucasian patients. Genomic DNA from 139 OP, 54 osteopenic (Ope) and 73 healthy (CTR) subjects were used for genotyping the rs731236 (TaqI), rs2228570 (FokI) and rs11568820 (Cdx2) polymorphisms of the VDR gene by an allelic discrimination assay. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis of VDR expression levels and pyrosequencing analysis of a VDR promoter CpG island were carried out in a subcohort (25 OP and 25 CTR) of subjects. Data obtained showed a significantly higher OP risk for rs11568820 G/A and A/A genotypes (p = 0.05). qRT-PCR revealed lower VDR gene expression levels in the OP group compared to CTR subjects (p = 0.0009), also associated with both the rs11568820 A/A genotype (p = 0.03) and femoral fragility fractures (p = 0.05). No association was found between the methylation pattern of the region analyzed of the VDR promoter and its expression levels. Our results identify a significative association between Cdx2 rs11568820 polymorphism and OP risk. In addition, the VDR transcriptomic profile suggests a putative interconnection with OP progression, providing a useful tool to stratify OP phenotype and fragility fracture risk.

The Memos theorize principles or "values" that in Calvino's view were especially relevant and important for literature (or, rather, poetry in the broader sense set forth by Harvard)-always seen in relation to other forms of discourse and expression-as it faced the new millennium, a millennium which Calvino, who died on September 19, 1985 at the age of 61 in the Santa Maria della Scala hospital in Siena (where he underwent emergency surgery after suffering a brain aneurysm), would not see.These futureoriented values for Calvino were also crucial to the reading and interpretation of poetic/literary works from the first and second millennia.The scholarly work included in this issue of California Italian Studies ranges in fact from studies pertaining to antiquity, the Middle Ages, and early modern literature and culture, to multidisciplinary reflections on literature, art, and science inspired by or based on the Memos, as well as critical problems and themes relevant to the contemporary era and the future of the humanities.Calvino, as became evident from the carefully ordered notebooks, outlines, and papers that he left on his desk, and on which the volume Lezioni americane was based, prevalently used English terms for the lectures' titles as he crafted, wrote, and revised them, reworking them (sometimes multiple times) before sending them off in batches to be translated by Patrick Creagh, who was not only a distinguished translator, but also a poet, living in Tuscany. 2 Geoffrey Brock, also a poet as well as an award-winning translator, is responsible for the new 2016 translation, which is the subject of his contribution to this issue of California Italian Studies. 3 Calvino was to present his lectures in English, in which he became increasingly proficient over the years after cultivating his passion for the language by translating several chapters of Lord Jim and then writing his 1947 tesi di laurea on Joseph Conrad, himself a peerless second-language learner of English whose stylistic precision and exactness were a lifelong model for Calvino, all the way to and including the Norton Lectures. 4 Traveling, lecturing and reading from his work in the United States over the years, Calvino, who eventually identified as a potential New Yorker, 5 was able to speak clearly in English (unlike many of his Italian compatriots who thought they could but were incomprehensible to their audiences), as is evident from some of the extant recordings, including that of his fall 1984 lecture at Mount Holyoke College, discussed by Ombretta Frau in this issue.A native of Cuba, Calvino also spoke Spanish well, especially after his marriage in Havana to Esther Singer, an Argentinian and a professional translator who liked to speak Spanish at home with their daughter Giovanna.In Paris, where the Calvinos lived from 1967 to 1980, Calvino became more fluent in French, conversing with Queneau and other members of the Oulipo and even attending Roland Barthes' seminars on Balzac's Sarrasine . 6 The literary horizon of the Memos is decidedly comparative, and Calvino quotes most of the non-Italian works in the original.The titles for the completed Norton lectures were 1. "Lightness"

The Vitamin D Receptor (VDR) mediates the actions of vitamin D, which has important roles in bone homeostasis, growth/differentiation of cells, immune functions and reduction of inflammation. Emerging evidences suggest that epigenetic modifications of the VDR gene, particularly DNA methylation, may contribute to the onset and progression of many human disorders. This review aims to summarize the available information on the role of VDR methylation signatures in different pathological contexts, including autoimmune diseases, infectious diseases, cancer and others. The reversible nature of DNA methylation could enable the development of therapeutic strategies, offering new avenues for the management of these worldwide diseases.

Heavy metal levels appear to be associated with low bone mineral density (BMD) and the consequent osteoporosis risk, but the relationship with the disease has not been clearly defined. The altered expression pattern of numerous genes, including detoxifying genes, seems to play a pivotal role in this context, leading to increased susceptibility to several diseases, including osteoporosis. The purpose of this study is to analyse circulating heavy metals levels and the expression of detoxifying genes in osteoporotic patients (OPs, n = 31), compared with healthy subjects (CTRs, n = 32). Heavy metals concentration in plasma samples was determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), and the subsequent expression analysis of NAD(P)H quinone dehydrogenase 1 ( NQO1 ), Catalase ( CAT ), and Metallothionein 1E ( MT1E ) genes in Peripheral Blood Mononuclear Cells (PBMCs) was assessed by real-time polymerase chain reaction (qRT-PCR). Copper (Cu), mercury (Hg), molybdenum (Mo) and lead (Pb) were found to be significantly higher in the plasma of OPs compared to CTRs. Analysis of the expression levels of detoxifying genes showed a significant decrease in CAT and MT1E in OP group. In addition, Cu correlated positively with the expression levels of both CAT and MT1E in CTRs group and MT1E in OPs. This study shows an increased circulating concentration of certain metals combined with an altered expression pattern of detoxifying genes in OPs, highlighting a novel aspect to be investigated in order to better characterize the role of metals in the pathogenesis of osteoporosis.

Myotonic dystrophy type 2 (DM2) is caused by CCTG repeat expansions in the CNBP gene, comprising 75 to >11,000 units and featuring extensive mosaicism, making it challenging to sequence fully expanded alleles. To overcome these limitations, we used PCR-free Cas9-mediated nanopore sequencing to characterize CNBP repeat expansions at the single-nucleotide level in nine DM2 patients. The length of normal and expanded alleles can be assessed precisely using this strategy, agreeing with traditional methods, and revealing the degree of mosaicism. We also sequenced an entire ~50 kbp expansion, which has not been achieved previously for DM2 or any other repeat-expansion disorders. Our approach precisely counted the repeats and identified the repeat pattern for both short interrupted and uninterrupted alleles. Interestingly, in the expanded alleles, only two DM2 samples featured the expected pure CCTG repeat pattern, while the other seven presented also TCTG blocks at the 3' end, which have not been reported before in DM2 patients, but confirmed hereby with orthogonal methods. The demonstrated approach simultaneously determines repeat length, structure/motif, and the extent of somatic mosaicism, promising to improve the molecular diagnosis of DM2 and achieve more accurate genotype-phenotype correlations for the better stratification of DM2 patients in clinical trials.