Eye involvement in patients with myotonic dystrophy

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Heart transplantation in patients with dystrophinopathic cardiomyopathy: Review of the literature and personal series

Cardiomyopathy associated with dystrophinopathies [Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), X-linked dilated cardiomyopathy (XL-dCM) and cardiomyopathy of Duchenne/Becker (DMD/BMD) carriers] is an increasing recognized manifestation of these neuromuscular disorders and notably contributes to their morbidity and mortality. Dystrophinopathic cardiomyopathy (DCM) is the result of the dystrophin protein deficiency at the myocardium level, parallel to the deficiency occurring at the skeletal muscle level. It begins as a "presymptomatic" stage in the first decade of life and evolves in a stepwise manner toward pictures of overt cardiomyopathy (hypertrophic stage, arrhythmogenic stage and dilated cardiomyopathy). The final stage caused by the extensive loss of cardiomyocytes results in an irreversible cardiac failure, characterized by frequent episodes of acute congestive heart failure (CHF), despite a correct pharmacological treatment. The picture of a severe dilated cardiomyopathy with intractable heart failure is typical of BMD, XL-dCM and cardiomyopathy of DMD/BMD carriers, while it is less frequently observed in patients with DMD. Heart transplantation (HT) is the only curative therapy for patients with dystrophinopathic end-stage heart failure who remain symptomatic despite an optimal medical therapy. However, no definitive figures exist in literature concerning the number of patients with DCM transplanted, and their outcome. This overview is to summarize the clinical outcomes so far published on the topic, to report the personal series of dystrophinopathic patients receiving heart transplantation and finally to provide evidence that heart transplantation is a safe and effective treatment for selected patients with end-stage DCM

Impact of the COVID-19 pandemic on neuromuscular rehabilitation setting. Part 2: patients and families' views on the received health care during the pandemic

This study explored views of users with muscular dystrophies and their caregivers on staff-user relationships and the treatments provided by a Rehabilitation Centre during the pandemic. Patients and relatives were asked to anonymously complete an open-ended questionnaire exploring their views on these aspects. Fifty-four patients and 40 caregivers gave their informed consent and participated in the survey. Fifty-three patients were adults, 28% suffering from Duchenne/Becker muscular dystrophy. Patients reported 269 comments on health care services provided during the pandemic, 132 (49%) concerning positive aspects and 137 (51%) negative aspects. The prompt restart of the rehabilitation therapies and the staff closeness over the pandemic were the practical aspects most frequently appreciated (46.9%), while closer family contacts and the perception of being able to rely on the Centre's constant support were the most cited psychological aspects (53.1%). Architectural barriers, difficulties in accessing public health services, economic difficulties, and lack of support from welfare and other agencies were the practical critical points most frequently reported (89%). In addition, social isolation, and loneliness due to fear of contagion were the most negative psychological aspects (10.1%). As regard the caregivers' views, participants reported 151 comments. Of these, 86 (56.9%) were positive and 65 (43.1%) were negative. Among the positive aspects, the psychological ones - such as closer family contacts, not feeling abandoned and counting on the constant Centre's professional support prevailed (53.5%). As for the negative aspects, most caregivers (92.6%) believe that the pandemic exacerbated their financial and bureaucratic difficulties, particularly in poorer families

Bi-Allelic DES Gene Variants Causing Autosomal Recessive Myofibrillar Myopathies Affecting Both Skeletal Muscles and Cardiac Function

Mutations in the human desmin gene (DES) may cause both autosomal dominant and recessive cardiomyopathies leading to heart failure, arrhythmias and atrio-ventricular blocks, or progressive myopathies. Cardiac conduction disorders, arrhythmias and cardiomyopathies usually associated with progressive myopathy are the main manifestations of autosomal dominant desminopathies, due to mono-allelic pathogenic variants. The recessive forms, due to bi-allelic variants, are very rare and exhibit variable phenotypes in which premature sudden cardiac death could also occur in the first or second decade of life. We describe a further case of autosomal recessive desminopathy in an Italian boy born of consanguineous parents, who developed progressive myopathy at age 12, and dilated cardiomyopathy four years later and died of intractable heart failure at age 17. Next Generation Sequencing (NGS) analysis identified the homozygous loss-of-function variant c.634C>T; p.Arg212*, which was likely inherited from both parents. Furthermore, we performed a comparison of clinical and genetic results observed in our patient with those of cases so far reported in the literature

Emerging perspectives on laminopathies

Giovanna Lattanzi,1,2 Sara Benedetti,3 Maria Rosaria D'Apice,4 Lorenzo Maggi,5 Nicola Carboni,6 Emanuela Scarano,7 Luisa Politano8 1National Research Council of Italy, Institute for Molecular Genetics (CNR-IGM), Unit of Bologna, 2Rizzoli Orthopedic Institute, Laboratory of Musculoskeletal Cell Biology, Bologna, 3Laboratory of Clinical Molecular Biology and Cytogenetics, San Raffaele Scientific Institute, Milan, 4Fondazione Policlinico Tor Vergata, Rome, 5Neuromuscular Diseases and Neuroimmunology Unit, IRCCS Neurological Institute C Besta, Milan, 6Division of Neurology, Hospital San Francesco, Nuoro, 7Pediatric Endocrinology and Rare Diseases Unit, Department of Pediatrics, S Orsola-Malpighi University Hospital, University of Bologna, Bologna, 8Department of Experimental Medicine, Cardiomyology and Medical Genetics, Second University of Naples, Naples, Italy Abstract: Laminopathies are a group of inherited disorders caused by mutations in the lamin A/C gene, and can affect diverse organs or tissues, or can be systemic, causing premature aging. In the present review, we report on the composition and structure of the nuclear lamina and the role of lamins in nuclear mechanics and their involvement in human diseases, and provide some examples of laminopathies and current therapeutic approaches. Keywords: lamin A/C, emerin, laminopathies, Emery–Dreifuss muscular dystrophy, Hutchinson–Gilford progeri

Affinity proteomics within rare diseases: a BIO‐NMD study for blood biomarkers of muscular dystrophies

Despite the recent progress in the broad‐scaled analysis of proteins in body fluids, there is still a lack in protein profiling approaches for biomarkers of rare diseases. Scarcity of samples is the main obstacle hindering attempts to apply discovery driven protein profiling in rare diseases. We addressed this challenge by combining samples collected within the BIO‐NMD consortium from four geographically dispersed clinical sites to identify protein markers associated with muscular dystrophy using an antibody bead array platform with 384 antibodies. Based on concordance in statistical significance and confirmatory results obtained from analysis of both serum and plasma, we identified eleven proteins associated with muscular dystrophy, among which four proteins were elevated in blood from muscular dystrophy patients: carbonic anhydrase III (CA3) and myosin light chain 3 (MYL3), both specifically expressed in slow‐twitch muscle fibers and mitochondrial malate dehydrogenase 2 (MDH2) and electron transfer flavoprotein A (ETFA). Using age‐matched sub‐cohorts, 9 protein profiles correlating with disease progression and severity were identified, which hold promise for the development of new clinical tools for management of dystrophinopathies

Genetic Modifiers of Duchenne Muscular Dystrophy and Dilated Cardiomyopathy.

OBJECTIVE: Dilated cardiomyopathy (DCM) is a major complication and leading cause of death in Duchenne muscular dystrophy (DMD). DCM onset is variable, suggesting modifier effects of genetic or environmental factors. We aimed to determine if polymorphisms previously associated with age at loss of independent ambulation (LoA) in DMD (rs28357094 in the SPP1 promoter, rs10880 and the VTTT/IAAM haplotype in LTBP4) also modify DCM onset. METHODS: A multicentric cohort of 178 DMD patients was genotyped by TaqMan assays. We performed a time-to-event analysis of DCM onset, with age as time variable, and finding of left ventricular ejection fraction \u3c 50% and/or end diastolic volume \u3e 70 mL/m2 as event (confirmed by a previous normal exam \u3c 12 months prior); DCM-free patients were censored at the age of last echocardiographic follow-up. RESULTS: Patients were followed up to an average age of 15.9 ± 6.7 years. Seventy-one/178 patients developed DCM, and median age at onset was 20.0 years. Glucocorticoid corticosteroid treatment (n = 88 untreated; n = 75 treated; n = 15 unknown) did not have a significant independent effect on DCM onset. Cardiological medications were not administered before DCM onset in this population. We observed trends towards a protective effect of the dominant G allele at SPP1 rs28357094 and recessive T allele at LTBP4 rs10880, which was statistically significant in steroid-treated patients for LTBP4 rs10880 (\u3c 50% T/T patients developing DCM during follow-up [n = 13]; median DCM onset 17.6 years for C/C-C/T, log-rank p = 0.027). CONCLUSIONS: We report a putative protective effect of DMD genetic modifiers on the development of cardiac complications, that might aid in risk stratification if confirmed in independent cohorts

TMEM5-associated dystroglycanopathy presenting with CMD and mild limb-girdle muscle involvement

The dystroglycanopathies, which are caused by reduced glycosylation of alpha-dystroglycan, are a heterogeneous group of neurodegenerative disorders characterized by variable brain and skeletal muscle involvement. Recently, mutations in TMEM5 have been described in severe dystroglycanopathies. We present the clinical, molecular and neuroimaging features of an Italian boy who had delayed developmental milestones with mild limb-girdle muscle involvement, bilateral frontotemporal polymicrogyria, moderate intellectual disability, and no cerebellar involvement. He also presented a cochlear dysplasia and harbored a reported mutation (p.A47Rfs*42) in TMEM5, detected using targeted next-generation sequencing. The relatively milder muscular phenotype and associated structural brain abnormalities distinguish this case from previously reported patients with severe dystroglycanopathies and expand the spectrum of TMEM5-associated disorders

The position of nonsense mutations can predict the phenotype severity : A survey on the DMD gene

A nonsense mutation adds a premature stop signal that hinders any further translation of a protein-coding gene, usually resulting in a null allele. To investigate the possible exceptions, we used theDMDgene as an ideal model. First, because dystrophin absence causes Duchenne muscular dystrophy (DMD), while its reduction causes Becker muscular dystrophy (BMD). Second, theDMDgene is X-linked and there is no second allele that can interfere in males. Third, databases are accumulating reports on many mutations and phenotypic data. Finally, becauseDMDmutations may have important therapeutic implications. For our study, we analyzed large databases (LOVD, HGMD and ClinVar) and literature and revised critically all data, together with data from our internal patients. We totally collected 2593 patients. Positioning these mutations along the dystrophin transcript, we observed a nonrandom distribution of BMD-associated mutations within selected exons and concluded that the position can be predictive of the phenotype. Nonsense mutations always cause DMD when occurring at any point in fifty-one exons. In the remaining exons, we found milder BMD cases due to early 5' nonsense mutations, if reinitiation can occur, or due to late 3' nonsense when the shortened product retains functionality. In the central part of the gene, all mutations in some in-frame exons, such as in exons 25, 31, 37 and 38 cause BMD, while mutations in exons 30, 32, 34 and 36 cause DMD. This may have important implication in predicting the natural history and the efficacy of therapeutic use of drug-stimulated translational readthrough of premature termination codons, also considering the action of internal natural rescuers. More in general, our survey confirm that a nonsense mutation should be not necessarily classified as a null allele and this should be considered in genetic counselling.Peer reviewe