SCN5A mutation is associated with a higher Shanghai Score in patients with type 1 Brugada ECG pattern.

AIMS: Brugada syndrome (BrS) is an inherited arrhythmic disease characterized by a coved ST-segment elevation in the right precordial electrocardiogram leads (type 1 ECG pattern) and is associated with a risk of malignant ventricular arrhythmias and sudden cardiac death. In order to assess the predictive value of the Shanghai Score System for the presence of a SCN5A mutation in clinical practice, we studied a cohort of 125 patients with spontaneous or fever/drug-induced BrS type 1 ECG pattern, variably associated with symptoms and a positive family history. METHODS: The Shanghai Score System items were collected for each patient and PR and QRS complex intervals were measured. Patients were genotyped through a next-generation sequencing (NGS) custom panel for the presence of SCN5A mutations and the common SCN5A polymorphism (H558R). RESULTS: The total Shanghai Score was higher in SCN5A+ patients than in SCN5A- patients. The 81% of SCN5A+ patients and the 100% of patients with a SCN5A truncating variant exhibit a spontaneous type 1 ECG pattern. A significant increase in PR (P = 0.006) and QRS (P = 0.02) was detected in the SCN5A+ group. The presence of the common H558R polymorphism did not significantly correlate with any of the items of the Shanghai Score, nor with the total score of the system. CONCLUSION: Data from our study suggest the usefulness of Shanghai Score collection in clinical practice in order to maximize genetic test appropriateness. Our data further highlight SCN5A mutations as a cause of conduction impairment in BrS patients.

mRNA in situ hybridization exhibits unbalanced nuclear/cytoplasmic dystrophin transcript repartition in Duchenne myogenic cells and skeletal muscle biopsies.

To gain insight on dystrophin (DMD) gene transcription dynamics and spatial localization, we assayed the DMD mRNA amount and defined its compartmentalization in myoblasts, myotubes, and skeletal muscle biopsies of Duchenne muscular dystrophy (DMD) patients. Using droplet digital PCR, Real-time PCR, and RNAscope in situ hybridization, we showed that the DMD transcript amount is extremely reduced in both DMD patients' cells and muscle biopsies and that mutation-related differences occur. We also found that, compared to controls, DMD transcript is dramatically reduced in the cytoplasm, as up to 90% of it is localized in nuclei, preferentially at the perinuclear region. Using RNA/protein colocalization experiments, we showed that about 40% of nuclear DMD mRNA is localized in the nucleoli in both control and DMD myogenic cells. Our results clearly show that mutant DMD mRNA quantity is strongly reduced in the patients' myogenic cells and muscle biopsies. Furthermore, mutant DMD mRNA compartmentalization is spatially unbalanced due to a shift in its localization towards the nuclei. This abnormal transcript repartition contributes to the poor abundance and availability of the dystrophin messenger in cytoplasm. This novel finding also has important repercussions for RNA-targeted therapies.

Digital health and Clinical Patient Management System (CPMS) platform utility for data sharing of neuromuscular patients: the Italian EURO-NMD experience.

BACKGROUND: The development of e-health technologies for teleconsultation and exchange of knowledge is one of the core purposes of European Reference Networks (ERNs), including the ERN EURO-NMD for rare neuromuscular diseases. Within ERNs, the Clinical Patient Management System (CPMS) is a web-based platform that seeks to boost active collaboration within and across the network, implementing data sharing. Through CPMS, it is possible to both discuss patient cases and to make patients' data available for registries and databases in a secure way. In this view, CPMS may be considered a sort of a temporary storage for patients' data and an effective tool for data sharing; it facilitates specialists' consultation since rare diseases (RDs) require multidisciplinary skills, specific, and outstanding clinical experience. Following European Union (EU) recommendation, and to promote the use of CPMS platform among EURO-NMD members, a twelve-month pilot project was set up to train the 15 Italian Health Care Providers (HCPs). In this paper, we report the structure, methods, and results of the teaching course, showing that tailored, ERN-oriented, training can significantly enhance the profitable use of the CPMS. RESULTS: Throughout the training course, 45 professionals learned how to use the many features of the CPMS, eventually opening 98 panels of discussion-amounting to 82% of the total panels included in the EURO-NMD. Since clinical, genetic, diagnostic, and therapeutic data of patients can be securely stored within the platform, we also highlight the importance of this platform as an effective tool to discuss and share clinical cases, in order to ease both case solving and data storing. CONCLUSIONS: In this paper, we discuss how similar course could help implementing the use of the platform, highlighting strengths and weaknesses of e-health for ERNs. The expected result is the creation of a "map" of neuromuscular patients across Europe that might be improved by a wider use of CPMS.

TeleNEwCARe: An Italian case-control telegenetics study in patients with Hereditary NEuromuscular and CARdiac diseases.

Telemedicine provides healthcare services remotely and represents a fundamental resource for the management of rare and fragile patients. Tele-health implementation is a main objective of the European Reference Networks (ERNs) mission to accelerate diagnosis for rare diseases. TeleNewCARe is a pilot case-control project which evaluates the efficacy and satisfaction of telegenetics for neuromuscular and cardiac adult patients, compared to face-to-face genetic counselling. The virtual sessions were co-hosted by a medical geneticist and a neurologist/cardiologist. Specific questionnaires (Clinical Genetics Satisfaction Questionnaire (CGS), Telemedicine Satisfaction Questionnaire (TSQ) and a Satisfaction Questionnaire for medical geneticists) were used to assess the effectiveness and fulfilment of telecounselling, both for patients and health care providers. Satisfaction expressed for telegenetics did not significantly differ from face-to-face counselling. The virtually enrolled patients declared they had the possibility to relate confidentially with the specialists, to share information and to be informed in an exhaustive way about their disease. Almost all patients declared themselves willing to reuse the telecounselling in the future. The multidisciplinary care was perceived as a significant added value. No overt technical problems were reported although the need for digital skills and tools can limit patients' compliance. Our experience supports telegenetics as a valid alternative to traditional genetic counselling in cardiac and neuromuscular patients. This innovative approach facilitates multidisciplinary care, grants a periodical follow up, without forcing patients to discomfortable travelling, and allows to maintain expert care. This result meets the ERNs needs to reduce patients' burden to access and monitor their healthcare.

DMD deletions underlining mild dystrophinopathies: literature review highlights phenotype-related mutation clusters and provides insights about genetic mechanisms and prognosis.

DMD gene pathogenic variations cause a spectrum of phenotypes, ranging from severe Duchenne muscular dystrophy, the Becker milder cases, the intermediate or very mild muscle phenotypes invariably characterized by high CK, and the ultrarare fully-asymptomatic cases. Besides these phenotypes, X-linked dilated cardiomyopathy is also caused by DMD mutations. Males carrying DMD deletions with absent or very mild phenotypes have been sparsely described. We performed a horizon scan on public datasets to enroll males with the above phenotypes and carrying DMD deletions to delineate myopathic genotype-phenotype relationships. We inventoried 81 males, who were divided into the following clinical categorization: fully-asymptomatic males aged >43 years (A, N = 22); isolated hyperCKemia (CK, N = 35); and mild weakness (any age) with or without high CK (WCK, N = 24). In all cases, deleted intervals were exons 2 to 55, and no downstream exons were ever involved, apart from an exon 78 deletion in a WCK patient. All deletions were in-frame apart from the known exception to the rule of exon 2 and exon 78. We correlated the mild phenotypes (A and CK) to deleted exons, intronic breakpoints, exon-exon junctions, 3' isoforms rule, and protein epitopes, and we found that some genetic profiles are exclusively/mainly occurring in A/CK phenotypes, suggesting they are compatible with a quasi-normal muscular performance. We discussed diverse pathogenic mechanisms that may contribute to mild dystrophinopathic phenotypes, and we tried to address some "critical" genetic configurations or exon content needed to preserve a semi-functional DMD gene.

Koolen-de Vries syndrome in a 63-year-old woman: Report of the oldest patient and a review of the adult phenotype.

Koolen-de Vries syndrome (KdVS) is a rare genetic disorder caused by a de novo microdeletion in chromosomal region 17q21.31 encompassing KANSL1 or by a de novo intragenic pathogenic variant of KANSL1. KdVS is typically characterized by intellectual disability (ID), variable from mild to severe, developmental psychomotor delay, especially of expressive language development, friendly disposition, and multiple systemic abnormalities. So far, most of the individuals affected by KdVS are diagnosed in infancy or in adolescence; to the best of our knowledge, only 34 (including ours) adults have been reported in literature. Here we present the adult phenotype of a 63-year-old Italian woman affected by KdVS, caused by a 17q21.31 microdeletion. She is, to our knowledge, the oldest affected individual reported so far. We collected her clinical history and photographs, as well as those of other 26 adult patients described so far and compared her to them. We propose that the cardinal features of KdVS in adulthood are ID (ranging from mild to severe, usually moderate), friendly behavior, musculoskeletal abnormalities (especially scoliosis), and facial dysmorphism (a long face and a pronounced pear-shape nose with bulbous overhanging nasal tip). Therefore, we suggest considering KdVS in differential diagnosis in adult patients characterized by these features.

The DMD gene and therapeutic approaches to restore dystrophin.

Duchenne muscular dystrophy (DMD) is a severe X-linked disease characterized by progressive muscle weakness. It is caused by a variety of DMD gene pathogenic variations (large deletions or duplications, and small mutations) which leads to the absence or to a decreased amount of dystrophin protein. The allelic Becker muscular dystrophy is characterized by later onset and milder muscle involvement, and other rarer phenotypes might also be associated, such as dilated cardiomyopathy, cognitive impairment, and other neurological signs. Following the identification of the genetic cause and the disease pathophysiology, innovative personalized therapies emerged. These can be categorized into two main groups: (1) therapies aiming at the restoration of dystrophin at the sarcolemma; (2) therapeutics dealing with secondary consequences of dystrophin deficiency. In this review we provide an overview about DMD genotype-phenotype correlation, and on main approaches to restore dystrophin as stop codon read-through, exon skipping, vector-mediated gene therapy, and genome-editing strategies, some of these are based on approved orphan drugs. Finally, we present the clinical potential of novel strategies combining therapies to correct the genetic defect and other approaches, targeting secondary downstream pathological cascade due to dystrophin deficiency.

Left Ventricular Myocardial Noncompaction with Advanced Atrioventricular Conduction Disorder and Ventricular Arrhythmias in a Young Patient: Role of MIB1 Gene.

Left ventricular noncompaction (LVNC) is a structural abnormality of the left ventricle, usually described as an isolated condition, or sometimes associated with other structural cardiac diseases. LVNC is generally asymptomatic, although it may present conduction disorders, arrhythmias, and heart failure. Here, we present the case of a patient who came to our attention with a severe LVNC phenotype associated with advanced AV conduction disorder, and supraventricular and ventricular arrhythmias at young age, in which a novel MIB1, likely pathogenic, variation has been identified.

Functional Characterization of Two Novel Mutations in SCN5A Associated with Brugada Syndrome Identified in Italian Patients.

BACKGROUND: Brugada syndrome (BrS) is an autosomal dominantly inherited cardiac disease characterized by "coved type" ST-segment elevation in the right precordial leads, high susceptibility to ventricular arrhythmia and a family history of sudden cardiac death. The SCN5A gene, encoding for the cardiac voltage-gated sodium channel Nav1.5, accounts for ~20-30% of BrS cases and is considered clinically relevant. METHODS: Here, we describe the clinical findings of two Italian families affected by BrS and provide the functional characterization of two novel SCN5A mutations, the missense variant Pro1310Leu and the in-frame insertion Gly1687_Ile1688insGlyArg. RESULTS: Despite being clinically different, both patients have a family history of sudden cardiac death and had history of arrhythmic events. The Pro1310Leu mutation significantly reduced peak sodium current density without affecting channel membrane localization. Changes in the gating properties of expressed Pro1310Leu channel likely account for the loss-of-function phenotype. On the other hand, Gly1687_Ile1688insGlyArg channel, identified in a female patient, yielded a nearly undetectable sodium current. Following mexiletine incubation, the Gly1687_Ile1688insGlyArg channel showed detectable, albeit very small, currents and biophysical properties similar to those of the Nav1.5 wild-type channel. CONCLUSIONS: Overall, our results suggest that the degree of loss-of-function shown by the two Nav1.5 mutant channels correlates with the aggressive clinical phenotype of the two probands. This genotype-phenotype correlation is fundamental to set out appropriate therapeutical intervention.

A patient with novel MBOAT7 variant: The cerebellar atrophy is progressive and displays a peculiar neurometabolic profile.

Mutations in the MBOAT7 gene have been described in 43 patients, belonging to 18 families, showing nonspecific clinical features (intellectual disability [ID], seizures, microcephaly or macrocephaly, and mild to moderate cerebellar atrophy) that make the clinical diagnosis difficult. Here we report the first Italian patient, a 22.5-year-old female, one of the oldest reported, born to apparently consanguineous parents. She shows severe ID, macrocephaly, seizures, aggressive outbursts, hyperphagia. We also documented progressive atrophy of the cerebellar vermis, that appeared not before the age of 7. The whole-exome sequencing of the trio identified a novel homozygous variant c.1057_1058delGCinsCA (p.Ala353His) in the MBOAT7 gene. The variant is considered to be likely pathogenic, since it is absent from population database and it lies in a highly conserved amino acid residue. This disorder has a neurometabolic pathogenesis, implicating a phospholipid remodeling abnormalities. A brain hydrogen-magnetic resonance spectroscopy (H-MRS) examination in our patient disclosed a peculiar neurometabolic profile in the cerebellar hemispheric region. This new finding could address the clinical suspicion of MBOAT7-related disorder, among the wide range of genetic conditions associated with ID and cerebellar atrophy. Moreover, the documented progression of cerebellar atrophy and the worsening of the disease only after some years open to the possibility of a therapeutic window after birth.