Publications by authors named "Luca Bello"

79 Publications

Evaluation of peripherin in biofluids of patients with motor neuron diseases.

Ann Clin Transl Neurol 2021 Jul 15. Epub 2021 Jul 15.

Department of Neurosciences, University of Padova, Padova, Italy.

Peripherin (PRPH), a type III intermediate filament, assembles with neurofilaments in neurons of the peripheral nervous system, including lower motor neurons (LMN). To evaluate the role of PRPH in LMN degeneration, we assessed PRPH and neurofilament light chain (NfL) in cerebrospinal fluid (CSF) and serum of 91 patients with motor neuron diseases (MND) and 69 controls. Overall, we found PRPH to be more concentrated in serum than in CSF. Serum PRPH resulted significantly increased in MND patients but it was unrelated to CSF-NfL or survival in the amyotrophic lateral sclerosis (ALS) subset. PRPH might represent a marker of LMN involvement.
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http://dx.doi.org/10.1002/acn3.51419DOI Listing
July 2021

Longitudinal motor function in proximal versus distal DMD pathogenic variants.

Muscle Nerve 2021 Jul 13. Epub 2021 Jul 13.

Center for Genetic Medicine, Children's Research Institute, Children's National Health System, Washington, District of Columbia, USA.

Introduction/aims: There is considerable heterogenicity in clinical outcomes in Duchenne muscular dystrophy (DMD). The aim of this study was to assess whether dystrophin gene (DMD) pathogenic variant location influences upper or lower extremity motor function outcomes in a large prospective cohort.

Methods: We used longitudinal timed and quantitative motor function measurements obtained from 154 boys with DMD over a 10-y period by the Cooperative International Neuromuscular Research Group Duchenne Natural History Study (CINRG-DNHS) to understand how the trajectories of motor function differ based on proximal versus distal DMD pathogenic variants. Proximal variants were defined as located proximal to 5' DMD intron 44, and distal variants as those including nucleotides 3' DMD including intron 44. Distal DMD variants are predicted to alter the expression of short dystrophin isoforms (Dp140, Dp116, and Dp71). We compared various upper extremity and lower extremity motor function measures in these two groups, after adjusting for total lifetime corticosteroid use.

Results: The time to loss-of-ambulation and timed motor function measurements of both upper and lower limbs over a 10-y period were comparable between boys with proximal (n = 53) and distal (n = 101) DMD pathogenic variants. Age had a significant effect on several motor function outcomes. Boys younger than 7 y of age (n = 49) showed gain in function whereas boys 7 y and older (n = 71) declined, regardless of dystrophin pathogenic variant location.

Discussion: The longitudinal decline in upper and lower motor function is independent of proximal versus distal location of DMD pathogenic variants.
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http://dx.doi.org/10.1002/mus.27371DOI Listing
July 2021

North Star Ambulatory Assessment changes in ambulant Duchenne boys amenable to skip exons 44, 45, 51, and 53: A 3 year follow up.

PLoS One 2021 25;16(6):e0253882. Epub 2021 Jun 25.

Department of Neurosciences, Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesù Children's Hospital, Rome, Italy.

Introduction: The aim of this study was to report 36-month longitudinal changes using the North Star Ambulatory Assessment (NSAA) in ambulant patients affected by Duchenne muscular dystrophy amenable to skip exons 44, 45, 51 or 53.

Materials And Methods: We included 101 patients, 34 had deletions amenable to skip exon 44, 25 exon 45, 19 exon 51, and 28 exon 53, not recruited in any ongoing clinical trials. Five patients were counted to skip exon 51 and 53 since they had a single deletion of exon 52.

Results: The difference between subgroups (skip 44, 45, 51 and 53) was significant at 12 (p = 0.043), 24 (p = 0.005) and 36 months (p≤0.001).

Discussion: Mutations amenable to skip exons 53 and 51 had lower baseline values and more negative changes than the other subgroups while those amenable to skip exon 44 had higher scores both at baseline and at follow up.

Conclusion: Our results confirm different progression of disease in subgroups of patients with deletions amenable to skip different exons. This information is relevant as current long term clinical trials are using the NSAA in these subgroups of mutations.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0253882PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8232423PMC
June 2021

Movement Disorders in Children with a Mitochondrial Disease: A Cross-Sectional Survey from the Nationwide Italian Collaborative Network of Mitochondrial Diseases.

J Clin Med 2021 May 12;10(10). Epub 2021 May 12.

IRCCS Fondazione Stella Maris, 56018 Pisa, Italy.

Movement disorders are increasingly being recognized as a manifestation of childhood-onset mitochondrial diseases (MDs). However, the spectrum and characteristics of these conditions have not been studied in detail in the context of a well-defined cohort of patients. We retrospectively explored a cohort of individuals with childhood-onset MDs querying the Nationwide Italian Collaborative Network of Mitochondrial Diseases database. Using a customized online questionnaire, we attempted to collect data from the subgroup of patients with movement disorders. Complete information was available for 102 patients. Movement disorder was the presenting feature of MD in 45 individuals, with a mean age at onset of 11 years. Ataxia was the most common movement disorder at onset, followed by dystonia, tremor, hypokinetic disorders, chorea, and myoclonus. During the disease course, most patients (67.7%) encountered a worsening of their movement disorder. Basal ganglia involvement, cerebral white matter changes, and cerebellar atrophy were the most commonly associated neuroradiological patterns. Forty-one patients harbored point mutations in the mitochondrial DNA, 10 carried mitochondrial DNA rearrangements, and 41 cases presented mutations in nuclear-DNA-encoded genes, the latter being associated with an earlier onset and a higher impairment in activities of daily living. Among our patients, 32 individuals received pharmacological treatment; clonazepam and oral baclofen were the most commonly used drugs, whereas levodopa and intrathecal baclofen administration were the most effective. A better delineation of the movement disorders phenotypes starting in childhood may improve our diagnostic workup in MDs, fine tuning management, and treatment of affected patients.
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http://dx.doi.org/10.3390/jcm10102063DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8151313PMC
May 2021

Striated muscle activator of Rho signalling (STARS) overexpression in the mdx mouse enhances muscle functional capacity and regulates the actin cytoskeleton and oxidative phosphorylation pathways.

Exp Physiol 2021 Jul 27;106(7):1597-1611. Epub 2021 May 27.

Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia.

New Findings: What is the central question of this study? Striated muscle activator of rho signalling (STARS) is an actin-binding protein that regulates transcriptional pathways controlling muscle function, growth and myogenesis, processes that are impaired in dystrophic muscle: what is the regulation of the STARS pathway in Duchenne muscular dystrophy (DMD)? What is the main finding and its importance? Members of the STARS signalling pathway are reduced in the quadriceps of patients with DMD and in mouse models of muscular dystrophy. Overexpression of STARS in the dystrophic deficient mdx mouse model increased maximal isometric specific force and upregulated members of the actin cytoskeleton and oxidative phosphorylation pathways. Regulating STARS may be a therapeutic approach to enhance muscle health.

Abstract: Duchenne muscular dystrophy (DMD) is characterised by impaired cytoskeleton organisation, cytosolic calcium handling, oxidative stress and mitochondrial dysfunction. This results in progressive muscle damage, wasting and weakness and premature death. The striated muscle activator of rho signalling (STARS) is an actin-binding protein that activates the myocardin-related transcription factor-A (MRTFA)/serum response factor (SRF) transcriptional pathway, a pathway regulating cytoskeletal structure and muscle function, growth and repair. We investigated the regulation of the STARS pathway in the quadriceps muscle from patients with DMD and in the tibialis anterior (TA) muscle from the dystrophin-deficient mdx and dko (utrophin and dystrophin null) mice. Protein levels of STARS, SRF and RHOA were reduced in patients with DMD. STARS, SRF and MRTFA mRNA levels were also decreased in DMD muscle, while Stars mRNA levels were decreased in the mdx mice and Srf and Mrtfa mRNAs decreased in the dko mice. Overexpressing human STARS (hSTARS) in the TA muscles of mdx mice increased maximal isometric specific force by 13% (P < 0.05). This was not associated with changes in muscle mass, fibre cross-sectional area, fibre type, centralised nuclei or collagen deposition. Proteomics screening followed by pathway enrichment analysis identified that hSTARS overexpression resulted in 31 upregulated and 22 downregulated proteins belonging to the actin cytoskeleton and oxidative phosphorylation pathways. These pathways are impaired in dystrophic muscle and regulate processes that are vital for muscle function. Increasing the STARS protein in dystrophic muscle improves muscle force production, potentially via synergistic regulation of cytoskeletal structure and energy production.
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http://dx.doi.org/10.1113/EP089253DOI Listing
July 2021

The nonsense mutation stop+4 model correlates with motor changes in Duchenne muscular dystrophy.

Neuromuscul Disord 2021 Jun 21;31(6):479-488. Epub 2021 Feb 21.

Pediatric Neurology, Università Cattolica del Sacro Cuore, Rome, Italy; Centro Clinico Nemo, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Largo Agostino Gemelli 8, Rome 00152, Italy. Electronic address:

The aim was to assess 3-year longitudinal data using 6MWT in 26 ambulant boys affected by DMD carrying nonsense mutations and to compare their results to other small mutations. We also wished to establish, within the nonsense mutations group, patterns of change according to several variables. Patients with nonsense mutations were categorized according to the stop codon type newly created by the mutation and also including the adjacent 5' (upstream) and 3' (downstream) nucleotides. No significant difference was found between nonsense mutations and other small mutations (p > 0.05) on the 6MWT. Within the nonsense mutations group, there was no difference in 6MWT when the patients were subdivided according to: Type of stop codon, frame status of exons involved, protein domain affected. In contrast, there was a difference when the stop codon together with the 3' adjacent nucleotide ("stop+4 model") was considered (p < 0.05) with patients with stop codon TGA and 3' adjacent nucleotide G (TGAG) having a more rapid decline. Our finding suggest that the stop+4 model may help in predicting functional changes. This data will be useful at the time of interpreting the long term follow up of patients treated with Ataluren that are becoming increasingly available.
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http://dx.doi.org/10.1016/j.nmd.2021.02.015DOI Listing
June 2021

Assessing Dysferlinopathy Patients Over Three Years With a New Motor Scale.

Ann Neurol 2021 05 26;89(5):967-978. Epub 2021 Feb 26.

Department of Neurology Children's National Health System, Washington, DC.

Objective: Dysferlinopathy is a muscular dystrophy with a highly variable clinical presentation and currently unpredictable progression. This variability and unpredictability presents difficulties for prognostication and clinical trial design. The Jain Clinical Outcomes Study of Dysferlinopathy aims to establish the validity of the North Star Assessment for Limb Girdle Type Muscular Dystrophies (NSAD) scale and identify factors that influence the rate of disease progression using NSAD.

Methods: We collected a longitudinal series of functional assessments from 187 patients with dysferlinopathy over 3 years. Rasch analysis was used to develop the NSAD, a motor performance scale suitable for ambulant and nonambulant patients. Generalized estimating equations were used to evaluate the impact of patient factors on outcome trajectories.

Results: The NSAD detected significant change in clinical progression over 1 year. The steepest functional decline occurred during the first 10 years after symptom onset, with more rapid decline noted in patients who developed symptoms at a younger age (p = 0.04). The most rapidly deteriorating group over the study was patients 3 to 8 years post symptom onset at baseline.

Interpretation: The NSAD is the first validated limb girdle specific scale of motor performance, suitable for use in clinical practice and clinical trials. Longitudinal analysis showed it may be possible to identify patient factors associated with greater functional decline both across the disease course and in the short-term for clinical trial preparation. Through further work and validation in this cohort, we anticipate that a disease model incorporating functional performance will allow for more accurate prognosis for patients with dysferlinopathy. ANN NEUROL 2021;89:967-978.
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http://dx.doi.org/10.1002/ana.26044DOI Listing
May 2021

The Pregnancy Outcomes Among Newly Arrived Asylum-Seekers in Italy: Implications of Public Health.

J Immigr Minor Health 2021 Apr 5;23(2):232-239. Epub 2020 Dec 5.

Department of Public Health and Infectious Diseases, Policlinico Umberto I Hospital. University of Rome Sapienza, Rome, Italy.

Background: Migration has a significant impact on overall health and pregnancy outcome. Despite the fact that growing volume of migration flows significantly engaging the public health system of European host countries, there is a lack of evidence concerning pregnancy outcomes of newly arrived asylum-seeking women.

Methods: Data about pregnant asylum seekers hosted in the Italian Reception Centers between the 1 st June 2016 and the 1st June 2018 were retrospectively collected and analysed in the present study. We examined the following pregnancy outcomes: miscarriage, self-induced abortion, voluntary pregnancy termination, live-birth; and studied potentially related socio-demographic factors.

Results: Out of the 110 pregnant women living in the reception centers, 44 (40%) had eutocic delivery, 8 (7.3%) dystocic delivery, 15 (13.6%) miscarriage, 17 (15.5%) self-induced abortion and 26 (23.6%) underwent voluntary pregnancy termination. Nigerian women were at a significantly higher risk of abortive outcomes for voluntary pregnancy termination (p < 0.001), miscarriage (p = 0.049) and self-induced abortion (p < 0.001). Being unmarried was significantly associated with voluntary pregnancy termination and self-induced abortion. Women who chose to undergo unsafe abortion did not result to have significantly lower educational levels, compared to women who preferred medical abortion.

Conclusion: This study offers first insights into pregnancy outcomes among asylum-seeking women in Italy. The country of origin and marital status seem to significantly impact on pregnancy outcome. We identified sub-groups of migrant women at increased risk of abortive outcomes, and highlight the need to improve care in order to promote migrant women's reproductive health.
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http://dx.doi.org/10.1007/s10903-020-01126-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7914189PMC
April 2021

Nusinersen safety and effects on motor function in adult spinal muscular atrophy type 2 and 3.

J Neurol Neurosurg Psychiatry 2020 11 11;91(11):1166-1174. Epub 2020 Sep 11.

Department of Neurology/Stroke Unit, Bolzano Hospital, Bolzano, Trentino-Alto Adige, Italy.

Objective: To retrospectively investigate safety and efficacy of nusinersen in a large cohort of adult Italian patients with spinal muscular atrophy (SMA).

Methods: Inclusion criteria were: (1) clinical and molecular diagnosis of SMA2 or SMA3; (2) nusinersen treatment started in adult age (>18 years); (3) clinical data available at least at baseline (T0-beginning of treatment) and 6 months (T6).

Results: We included 116 patients (13 SMA2 and 103 SMA3) with median age at first administration of 34 years (range 18-72). The Hammersmith Functional Rating Scale Expanded (HFMSE) in patients with SMA3 increased significantly from baseline to T6 (median change +1 point, p<0.0001), T10 (+2, p<0.0001) and T14 (+3, p<0.0001). HFMSE changes were independently significant in SMA3 sitter and walker subgroups. The Revised Upper Limb Module (RULM) in SMA3 significantly improved between T0 and T14 (median +0.5, p=0.012), with most of the benefit observed in sitters (+2, p=0.018). Conversely, patients with SMA2 had no significant changes of median HFMSE and RULM between T0 and the following time points, although a trend for improvement of RULM was observed in those with some residual baseline function. The rate of patients showing clinically meaningful improvements (as defined during clinical trials) increased from 53% to 69% from T6 to T14.

Conclusions: Our data provide further evidence of nusinersen safety and efficacy in adult SMA2 and SMA3, with the latter appearing to be cumulative over time. In patients with extremely advanced disease, effects on residual motor function are less clear.
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http://dx.doi.org/10.1136/jnnp-2020-323822DOI Listing
November 2020

Limb girdle muscular dystrophy due to gene mutations: new mutations expand the clinical spectrum of a still challenging diagnosis.

Acta Myol 2020 Jun 1;39(2):67-82. Epub 2020 Jun 1.

Dino Ferrari Center, Neurology Unit, Department of Pathophysiology and Transplantation, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Italy.

Mutations in gene, encoding merosin, are generally responsible of a severe congenital-onset muscular dystrophy (CMD type 1A) characterized by severe weakness, merosin absence at muscle analysis and white matter alterations at brain Magnetic Resonance Imaging (MRI). Recently, mutations have been acknowledged as responsible of LGMD R23, despite only few cases with slowly progressive adult-onset and partial merosin deficiency have been reported. We describe 5 independent Italian subjects presenting with progressive limb girdle muscular weakness, brain white matter abnormalities, merosin deficiency and gene mutations. We detected 7 different mutations, 6 of which are new. All patients showed normal psicomotor development and slowly progressive weakness with onset spanning from childhood to forties. Creatin-kinase levels were moderately elevated. One patient showed dilated cardiomyopathy. Muscle MRI allowed to evaluate the degree and pattern of muscular involvement in all patients. Brain MRI was fundamental in order to address and/or support the molecular diagnosis, showing typical widespread white matter hyperintensity in T2-weighted sequences. Interestingly these alterations were associated with central nervous system involvement in 3 patients who presented epilepsy and migraine. Muscle biopsy commonly but not necessarily revealed dystrophic features. Western-blot was usually more accurate than immunohystochemical analysis in detecting merosin deficiency. The description of these cases further enlarges the clinical spectrum of -related disorders. Moreover, it supports the inclusion of LGMD R23 in the new classification of LGMD. The central nervous system involvement was fundamental to address the diagnosis and should be always included in the diagnostic work-up of undiagnosed LGMD.
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http://dx.doi.org/10.36185/2532-1900-009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7460730PMC
June 2020

Estimating the impact of COVID-19 pandemic on services provided by Italian Neuromuscular Centers: an Italian Association of Myology survey of the acute phase.

Acta Myol 2020 Jun 1;39(2):57-66. Epub 2020 Jun 1.

Child and Adolescent Unit, IRCCS Mondino Foundation, Pavia, Italy.

Introduction: Since February 2020, the outbreak of COVID-19 in Italy has forced the health care system to undergo profound rearrangements in its services and facilities, especially in the worst-hit areas in Northern Italy. In this setting, inpatient and outpatient services had to rethink and reorganize their activities to meet the needs of patients during the "lockdown". The Italian Association of Myology developed a survey to estimate the impact of these changes on patients affected by neuromuscular disorders and on specialized neuromuscular centers during the acute phase of COVID-19 pandemic.

Methods: We developed an electronic survey that was sent to neuromuscular centers affiliated with the Italian Association of Myology, assessing changes in pharmacological therapies provision, outpatient clinical and instrumental services, support services (physiotherapy, nursing care, psychological support) and clinical trials.

Results: 40% of surveyed neuromuscular centers reported a reduction in outpatient visit and examinations (44.5% of centers in Northern regions; 25% of centers in Central regions; 50% of centers in Southern regions). Twenty-two% of centers postponed in-hospital administration of therapies for neuromuscular diseases (23.4% in Northern regions; 13.0% in Central regions; 20% in Southern regions). Diagnostic and support services (physiotherapy, nursing care, psychological support) were suspended in 57% of centers (66/43/44% in Northern, Central and Southern centers respectively) Overall, the most affected services were rehabilitative services and on-site outpatient visits, which were suspended in 93% of centers. Strategies adopted by neuromuscular centers to overcome these changes included maintaining urgent on-site visits, addressing patients to available services and promoting remote contact and telemedicine.

Conclusions: Overall, COVID-19 pandemic resulted in a significant disruption of clinical and support services for patients with neuromuscular diseases. Despite the efforts to provide telemedicine consults to patients, this option could be promoted and improved further. A close collaboration between the different neuromuscular centers and service providers as well as further implementation of telehealth platforms are necessary to ensure quality care to NMD patients in the near future and in case of recurrent pandemic waves.
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http://dx.doi.org/10.36185/2532-1900-008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7460733PMC
June 2020

New genotype-phenotype correlations in a large European cohort of patients with sarcoglycanopathy.

Brain 2020 09;143(9):2696-2708

Center of Translational and Experimental Myology, IRCCS Istituto Giannina Gaslini, Genova, Italy.

Sarcoglycanopathies comprise four subtypes of autosomal recessive limb-girdle muscular dystrophies (LGMDR3, LGMDR4, LGMDR5 and LGMDR6) that are caused, respectively, by mutations in the SGCA, SGCB, SGCG and SGCD genes. In 2016, several clinicians involved in the diagnosis, management and care of patients with LGMDR3-6 created a European Sarcoglycanopathy Consortium. The aim of the present study was to determine the clinical and genetic spectrum of a large cohort of patients with sarcoglycanopathy in Europe. This was an observational retrospective study. A total of 33 neuromuscular centres from 13 different European countries collected data of the genetically confirmed patients with sarcoglycanopathy followed-up at their centres. Demographic, genetic and clinical data were collected for this study. Data from 439 patients from 13 different countries were collected. Forty-three patients were not included in the analysis because of insufficient clinical information available. A total of 159 patients had a confirmed diagnosis of LGMDR3, 73 of LGMDR4, 157 of LGMDR5 and seven of LGMDR6. Patients with LGMDR3 had a later onset and slower progression of the disease. Cardiac involvement was most frequent in LGMDR4. Sixty per cent of LGMDR3 patients carried one of the following mutations, either in a homozygous or heterozygous state: c.229C>T, c.739G>A or c.850C>T. Similarly, the most common mutations in LMGDR5 patients were c.525delT or c.848G>A. In LGMDR4 patients the most frequent mutation was c.341C>T. We identified onset of symptoms before 10 years of age and residual protein expression lower than 30% as independent risk factors for losing ambulation before 18 years of age, in LGMDR3, LGMDR4 and LGMDR5 patients. This study reports clinical, genetic and protein data of a large European cohort of patients with sarcoglycanopathy. Improving our knowledge about these extremely rare autosomal recessive forms of LGMD was helped by a collaborative effort of neuromuscular centres across Europe. Our study provides important data on the genotype-phenotype correlation that is relevant for the design of natural history studies and upcoming interventional trials in sarcoglycanopathies.
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http://dx.doi.org/10.1093/brain/awaa228DOI Listing
September 2020

Evaluation of mexiletine effect on conduction delay and bradyarrhythmic complications in patients with myotonic dystrophy type 1 over long-term follow-up.

Heart Rhythm 2020 11 7;17(11):1944-1950. Epub 2020 Jun 7.

Department of Cardiac, Thoracic and Vascular Sciences and Public Health, University of Padova, Padova, Italy.

Background: Myotonic dystrophy type 1 (DM1) is a multisystemic disorder characterized by progressive cardiac conduction impairment, arrhythmias, and sudden death. Mexiletine is a sodium channel blocker drug used by patients with DM1 for treatment of myotonia, even though definitive proof of its safety over long-term follow-up is lacking.

Objective: The purpose of this study was to assess the impact of mexiletine for treatment of neurological symptoms on the composite endpoint of significant electrocardiogram modification (new onset or worsening of atrioventricular [AV] or intraventricular conduction delay) and bradyarrhythmic complications requiring pacemaker (PM) implantation (advanced AV block, symptomatic sinus pause >3 seconds).

Methods: This retrospective longitudinal study included a series of consecutive patients with genetically confirmed DM1 evaluated at our neurology and cardiology clinics from January 1, 2011, to January 1, 2020, who received mexiletine 200 mg twice daily. Patients with a PM, implantable cardioverter-defibrillator, or severe conduction abnormality (PQ interval ≥230 ms, complete bundle branch block, or atrial fibrillation) at enrollment were excluded.

Results: The study comprised 18 mexiletine-treated patients and 68 mexiletine-free controls. Over median follow-up of 53 months, the endpoint was reached by 4 (22%) mexiletine-treated patients and 23 (33%) non-mexiletine-treated patients (log-rank P = .45). In 3 non-mexiletine-treated patients, bradyarrhythmic complications requiring PM implantation were observed. At univariable analysis, only the presence of mild conduction delay (first-degree AV block with PQ interval <230 ms or left anterior fascicular block) at baseline predicted the endpoint (hazard ratio 2.22; 95% confidence interval 1.04-4.76).

Conclusion: Mexiletine 200 mg twice daily is safe in patients with DM1 and no severe conduction abnormality.
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http://dx.doi.org/10.1016/j.hrthm.2020.05.043DOI Listing
November 2020

Genetic modifiers of respiratory function in Duchenne muscular dystrophy.

Ann Clin Transl Neurol 2020 05 28;7(5):786-798. Epub 2020 Apr 28.

Neuromuscular Center, AOU Città della Salute e della Scienza, University of Torino, Turin, Italy.

Objective: Respiratory insufficiency is a major complication of Duchenne muscular dystrophy (DMD). Its progression shows considerable interindividual variability, which has been less thoroughly characterized and understood than in skeletal muscle. We collected pulmonary function testing (PFT) data from a large retrospective cohort followed at Centers collaborating in the Italian DMD Network. Furthermore, we analyzed PFT associations with different DMD mutation types, and with genetic variants in SPP1, LTBP4, CD40, and ACTN3, known to modify skeletal muscle weakness in DMD. Genetic association findings were independently validated in the Cooperative International Neuromuscular Research Group Duchenne Natural History Study (CINRG-DNHS).

Methods And Results: Generalized estimating equation analysis of 1852 PFTs from 327 Italian DMD patients, over an average follow-up time of 4.5 years, estimated that forced vital capacity (FVC) declined yearly by -4.2%, forced expiratory volume in 1 sec by -5.0%, and peak expiratory flow (PEF) by -2.9%. Glucocorticoid (GC) treatment was associated with higher values of all PFT measures (approximately + 15% across disease stages). Mutations situated 3' of DMD intron 44, thus predicted to alter the expression of short dystrophin isoforms, were associated with lower (approximately -6%) PFT values, a finding independently validated in the CINRG-DNHS. Deletions amenable to skipping of exon 51 and 53 were independently associated with worse PFT outcomes. A meta-analysis of the two cohorts identified detrimental effects of SPP1 rs28357094 and CD40 rs1883832 minor alleles on both FVC and PEF.

Interpretation: These findings support GC efficacy in delaying respiratory insufficiency, and will be useful for the design and interpretation of clinical trials focused on respiratory endpoints in DMD.
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http://dx.doi.org/10.1002/acn3.51046DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7261745PMC
May 2020

The Genetic Landscape of Dystrophin Mutations in Italy: A Nationwide Study.

Front Genet 2020 3;11:131. Epub 2020 Mar 3.

Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.

Dystrophinopathies are inherited diseases caused by mutations in the dystrophin () gene for which testing is mandatory for genetic diagnosis, reproductive choices and eligibility for personalized trials. We genotyped the gene in our Italian cohort of 1902 patients (BMD n = 740, 39%; DMD n =1162, 61%) within a nationwide study involving 11 diagnostic centers in a 10-year window (2008-2017). In DMD patients, we found deletions in 57%, duplications in 11% and small mutations in 32%. In BMD, we found deletions in 78%, duplications in 9% and small mutations in 13%. In BMD, there are a higher number of deletions, and small mutations are more frequent than duplications. Among small mutations that are generally frequent in both phenotypes, 44% of DMD and 36% of BMD are nonsense, thus, eligible for stop codon read-through therapy; 63% of all out-of-frame deletions are eligible for single exon skipping. Patients were also assigned to Italian regions and showed interesting regional differences in mutation distribution. The full genetic characterization in this large, nationwide cohort has allowed us to draw several correlations between DMD/BMD genotype landscapes and mutation frequency, mutation types, mutation locations along the gene, exon/intron architecture, and relevant protein domain, with effects on population genetic characteristics and new personalized therapies.
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http://dx.doi.org/10.3389/fgene.2020.00131DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7063120PMC
March 2020

TCTEX1D1 is a genetic modifier of disease progression in Duchenne muscular dystrophy.

Eur J Hum Genet 2020 06 2;28(6):815-825. Epub 2020 Jan 2.

Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.

Duchenne muscular dystrophy (DMD) is caused by pathogenic variants in the DMD gene leading to the lack of dystrophin. Variability in the disease course suggests that other factors influence disease progression. With this study we aimed to identify genetic factors that may account for some of the variability in the clinical presentation. We compared whole-exome sequencing (WES) data in 27 DMD patients with extreme phenotypes to identify candidate variants that could affect disease progression. Validation of the candidate SNPs was performed in two independent cohorts including 301 (BIO-NMD cohort) and 109 (CINRG cohort of European ancestry) DMD patients, respectively. Variants in the Tctex1 domain containing 1 (TCTEX1D1) gene on chromosome 1 were associated with age of ambulation loss. The minor alleles of two independent variants, known to affect TCTEX1D1 coding sequence and induce skipping of its exon 4, were associated with earlier loss of ambulation. Our data show that disease progression of DMD is affected by a new locus on chromosome 1 and demonstrate the possibility to identify genetic modifiers in rare diseases by studying WES data in patients with extreme phenotypes followed by multiple layers of validation.
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http://dx.doi.org/10.1038/s41431-019-0563-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7253478PMC
June 2020

The Role of Motor System in Mental Rotation: New Insights from Myotonic Dystrophy Type 1.

J Int Neuropsychol Soc 2020 05 11;26(5):492-502. Epub 2019 Dec 11.

Padova Neuroscience Center, Padova, Italy.

Objective: This study explored mental rotation (MR) performance in patients with myotonic dystrophy 1 (DM1), an inherited neuromuscular disorder dominated by muscular symptoms, including muscle weakness and myotonia. The aim of the study was twofold: to gain new insights into the neurocognitive mechanisms of MR and to better clarify the cognitive profile of DM1 patients. To address these aims, we used MR tasks involving kinds of stimuli that varied for the extent to which they emphasized motor simulation and activation of body representations (body parts) versus visuospatial imagery (abstract objects). We hypothesized that, if peripheral sensorimotor feedback system plays a pivotal role in modulating MR performance, then DM1 patients would exhibit more difficulties in mentally rotating hand stimuli than abstract objects.

Method: Twenty-four DM1 patients and twenty-four age- and education-matched control subjects were enrolled in the study and were required to perform two computerized MR tasks involving pictures of hands and abstract objects.

Results: The analysis of accuracy showed that patients had impaired MR performance when the angular disparities between the stimuli were higher. Notably, as compared to controls, patients showed slower responses when the stimuli were hands, whereas no significant differences when stimuli were objects.

Conclusion: The findings are coherent with the embodied cognition view, indicating a tight relation between body- and motor-related processes and MR. They suggest that peripheral, muscular, abnormalities in DM1 lead to alterations in manipulation of motor representations, which in turn affect MR, especially when body parts are to mentally rotate.
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http://dx.doi.org/10.1017/S1355617719001383DOI Listing
May 2020

Teaching an Old Molecule New Tricks: Drug Repositioning for Duchenne Muscular Dystrophy.

Int J Mol Sci 2019 Nov 30;20(23). Epub 2019 Nov 30.

Department of Biomedical Sciences and Interuniversity Institute of Myology (IIM), University of Padova, via U. Bassi 58/B, 35131 Padua, Italy.

Duchenne muscular dystrophy (DMD) is one of the most severe forms of inherited muscular dystrophies. The disease is caused by the lack of dystrophin, a structurally essential protein; hence, a definitive cure would necessarily have to pass through some form of gene and/or cell therapy. Cell- and genetic-based therapeutics for DMD have been explored since the 1990s and recently, two of the latter have been approved for clinical use, but their efficacy is still very low. In parallel, there have been great ongoing efforts aimed at targeting the downstream pathogenic effects of dystrophin deficiency using classical pharmacological approaches, with synthetic or biological molecules. However, as it is always the case with rare diseases, R&D costs for new drugs can represent a major hurdle for researchers and patients alike. This problem can be greatly alleviated by experimenting the use of molecules that had originally been developed for different conditions, a process known as drug repurposing or drug repositioning. In this review, we will describe the state of the art of such an approach for DMD, both in the context of clinical trials and pre-clinical studies
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http://dx.doi.org/10.3390/ijms20236053DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6929176PMC
November 2019

Influence of β adrenergic receptor genotype on risk of nocturnal ventilation in patients with Duchenne muscular dystrophy.

Respir Res 2019 Oct 16;20(1):221. Epub 2019 Oct 16.

Department of Neurosciences, University of Padova, Padova, Italy.

Duchenne muscular dystrophy (DMD) is a progressive neuromuscular disease resulting in severe respiratory derangements. As such, DMD patients are at a high risk of nocturnal hypoventilation, thereby requiring nocturnal ventilation (NV). To this end, NV is an important clinical milestone in the management of DMD. Emerging evidence suggests that ß adrenergic receptors (ADRB2) may play a role in determining respiratory function, whereby more functional ADRB2 genotype variants (e.g., Gly16) are associated with improved pulmonary function and respiratory muscle strength. These findings suggest that the more functional ADRB2 genotype may help to preserve respiratory function in patients with DMD. The purpose of this study was to identify the influence of ADRB2 genotype on the risk of NV use in DMD. Data from the CINRG Duchenne Natural History Study including 175 DMD patients (3-25 yrs) were analyzed focusing on ADRB2 genotype variants. Time-to-event analyses were used to examine differences in the age at prescription of full-time NV use between genotypes. There were no differences between genotype groups in age, height, weight, corticosteroid use, proportion of ambulatory patients, or age at loss of ambulation. DMD patients expressing the Gly16 polymorphism had a significantly (P < 0.05) lower mean age at NV prescription compared with those patients expressing the Arg16 polymorphism (21.80 ± 0.59 yrs. vs 25.91 ± 1.31 yrs., respectively). In addition, a covariate-adjusted Cox model revealed that the Gly16 variant group possessed a 6.52-fold higher risk of full-time NV use at any given age compared with the Arg16 polymorphism group. These data suggest that genetic variations in the ADRB2 gene may influence the age at which DMD patients are first prescribed NV, whereby patients with the Gly16 polymorphism are more likely to require NV assistance at an earlier age than their Arg16 counterparts.
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http://dx.doi.org/10.1186/s12931-019-1200-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6796481PMC
October 2019

European muscle MRI study in limb girdle muscular dystrophy type R1/2A (LGMDR1/LGMD2A).

J Neurol 2020 Jan 25;267(1):45-56. Epub 2019 Sep 25.

APHP, Department of Radiology, Garches Neuromuscular Center (GNMH), Raymond Poincaré University Hospital (UVSQ, U 1179), Garches, France.

Background: Limb girdle muscular dystrophy type R1/2A (LGMDR1/LGMD2A) is a progressive myopathy caused by deficiency of calpain 3, a calcium-dependent cysteine protease of skeletal muscle, and it represents the most frequent type of LGMD worldwide. In the last few years, muscle magnetic resonance imaging (MRI) has been proposed as a tool for identifying patterns of muscular involvement in genetic disorders and as a biomarker of disease progression in muscle diseases. In this study, 57 molecularly confirmed LGMDR1 patients from a European cohort (age range 7-78 years) underwent muscle MRI and a global evaluation of functional status (Gardner-Medwin and Walton score and ability to raise the arms).

Results: We confirmed a specific pattern of fatty substitution involving predominantly the hip adductors and hamstrings in lower limbs. Spine extensors were more severely affected than spine rotators, in agreement with higher incidence of lordosis than scoliosis in LGMDR1. Hierarchical clustering of lower limb MRI scores showed that involvement of anterior thigh muscles discriminates between classes of disease progression. Severity of muscle fatty substitution was significantly correlated with CAPN3 mutations: in particular, patients with no or one "null" alleles showed a milder involvement, compared to patients with two null alleles (i.e., predicting absence of calpain-3 protein). Expectedly, fat infiltration scores strongly correlated with functional measures. The "pseudocollagen" sign (central areas of sparing in some muscle) was associated with longer and more severe disease course.

Conclusions: We conclude that skeletal muscle MRI represents a useful tool in the diagnostic workup and clinical management of LGMDR1.
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http://dx.doi.org/10.1007/s00415-019-09539-yDOI Listing
January 2020

Safety and efficacy of edaravone compared to historical controls in patients with amyotrophic lateral sclerosis from North-Eastern Italy.

J Neurol Sci 2019 Sep 6;404:47-51. Epub 2019 Jun 6.

Neuromuscular Center, Department of Neurosciences, University of Padova, Italy. Electronic address:

Objective: To test efficacy and tolerability of edaravone in patients with amyotrophic lateral sclerosis (ALS) originating from North-Eastern Italy.

Methods: We compared 3-month and 6-month changes of ALSFRS-R score, FVC value, and MRC score of 31 consecutive patients with ALS who were treated with edaravone to those of 50 historical ALS patients who were not treated with edaravone.

Results: No significant difference for any functional measures was found between the two groups at each time point as compared to baseline. In treated patients, we also observed creatinine values to significantly decrease at 3 and 6 months (p = 0.0078 and 0.030, respectively) and ALSAQ5 score to significantly increase (i.e. worse quality of life) at 3 and 6 months (p = 0.0005 and 0.0078, respectively). Yet, we observed an overall safety of the medication over the 6-month period of observation.

Conclusions: Our retrospective study suggests no benefit of edaravone on ALS in populations of Caucasian ancestry.
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http://dx.doi.org/10.1016/j.jns.2019.06.006DOI Listing
September 2019

Long-term natural history data in Duchenne muscular dystrophy ambulant patients with mutations amenable to skip exons 44, 45, 51 and 53.

PLoS One 2019 25;14(6):e0218683. Epub 2019 Jun 25.

Pediatric Neurology, Department of Woman and Child Health and Public Health, Child Health Area, Università Cattolica del Sacro Cuore, Rome, Italy.

Introduction: The aim of this international collaborative effort was to report 36-month longitudinal changes using the 6MWT in ambulant patients affected by Duchenne muscular dystrophy amenable to skip exons 44, 45, 51 or 53.

Materials And Methods: Of the 92 patients included in the study, 24 had deletions amenable to skip exon 44, 27 exon 45, 18 exon 51, and 28 exon 53. Five patients with a single deletion of exon 52 were counted in both subgroups skipping exon 51 and 53.

Results: The difference between subgroups amenable to skip different exons was not significant at 12 months but became significant at both 24 (p≤0.05) and 36 months (p≤0.01).

Discussion: Mutations amenable to skip exon 53 had lower baseline values and more negative changes than the other subgroups while those amenable to skip exon 44 had better results both at baseline and at follow up. Deletions amenable to skip exon 45 were associated with a more variable pattern of progression. Single exon deletions were more often associated with less drastic changes but this was not always true in individual cases.

Conclusion: Our results confirm that the progression of disease can differ between patients with different deletions, although the changes only become significant from 24 months onwards. This information is relevant because there are current clinical trials specifically targeting patients with these subgroups of mutations.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0218683PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6592545PMC
February 2020

The "Usual Suspects": Genes for Inflammation, Fibrosis, Regeneration, and Muscle Strength Modify Duchenne Muscular Dystrophy.

J Clin Med 2019 May 10;8(5). Epub 2019 May 10.

Department of Neurosciences, University of Padova, 35128 Padova, Italy.

Duchenne muscular dystrophy (DMD), the most severe form of dystrophinopathy, is quite homogeneous with regards to its causative biochemical defect, i.e., complete dystrophin deficiency, but not so much with regards to its phenotype. For instance, muscle weakness progresses to the loss of independent ambulation at a variable age, starting from before 10 years, to even after 16 years (with glucocorticoid treatment). Identifying the bases of such variability is relevant for patient counseling, prognosis, stratification in trials, and identification of therapeutic targets. To date, variants in five loci have been associated with variability in human DMD sub-phenotypes: , , , , and . Four of these genes (, , , and ) are implicated in several interconnected molecular pathways regulating inflammatory response to muscle damage, regeneration, and fibrosis; while is known as "the gene for speed", as it contains a common truncating polymorphism (18% of the general population), which reduces muscle power and sprint performance. Studies leading to the identification of these modifiers were mostly based on a "candidate gene" approach, hence the identification of modifiers in "usual suspect" pathways, which are already known to modify muscle in disease or health. Unbiased approaches that are based on genome mapping have so far been applied only initially, but they will probably represent the focus of future developments in this field, and will hopefully identify novel, "unsuspected" therapeutic targets. In this article, we summarize the state of the art of modifier loci of human dystrophin deficiency, and attempt to assess their relevance and implications on both clinical management and translational research .
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http://dx.doi.org/10.3390/jcm8050649DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6571893PMC
May 2019

Whole-Body Muscle Magnetic Resonance Imaging in Glycogen-Storage Disease Type III.

Muscle Nerve 2019 07 24;60(1):72-79. Epub 2019 Apr 24.

APHP, Service de Radiologie GHU PIFO pôle neuro-locomoteur, Hôpital Raymond Poincaré, Garches, France.

Introduction: The main objective of this study was to describe muscle involvement on whole-body magnetic resonance imaging scans in adults at different stages of glycogen-storage disease type III (GSDIII).

Methods: Fifteen patients, 16-59 years of age, were examined on a 3-T system. The examinations consisted of coronal and axial T1-weighted images or fat images with a Dixon technique, and were scored for 47 muscles using Mercuri's classification. Muscle changes consisted of internal bright signals of fatty replacement.

Results: Distribution across muscles showed predominant signal alteration in the lower limbs and postural muscles. This finding is consistent with the overall clinical presentation of GSDIII and the results of heatmap scores. Review of the MRI scans provided new information regarding recurrent muscle changes, particularly in the soleus, gastrocnemius medial head, and thoracic extensor muscles.

Discussion: Whole-body muscle imaging provides clinically relevant information regarding muscle involvement in GSDIII. A severity score may contribute to improved patient management. Muscle Nerve, 2019.
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http://dx.doi.org/10.1002/mus.26483DOI Listing
July 2019

Lipomatosis Incidence and Characteristics in an Italian Cohort of Mitochondrial Patients.

Front Neurol 2019 27;10:160. Epub 2019 Feb 27.

Department of Clinical and Experimental Medicine, UOC Neurologia e Malattie Neuromuscolari, University of Messina, Messina, Italy.

Lipomas have often been associated with mtDNA mutations and were mainly observed in patients with mutation in mitochondrial tRNAlysine which is also the most frequent mutation associated with MERRF. Up to date, no systematic studies have been developed in order to assess the incidence of lipomas in large cohorts of mitochondrial patients.The aim of this study is to analyze the incidence and characteristics of lipomas among an Italian cohort of patients with mitochondrial diseases. A retrospective, database-based study (Nation-wide Italian Collaborative Network of Mitochondrial Diseases) of patients with lipomas was performed. A total of 22 (1.7%) patients with lipomas have been identified among the 1,300 mitochondrial patients, enrolled in the Italian database. In about 18% multiple systemic lipomatosis (MSL) was the only clinical manifestation; 54% of patients showed a classical MERRF syndrome. Myopathy, alone or in association with other symptoms, was found in 27% of patients. Lactate was elevated in all the 12 patients in which was measured. Muscle biopsy was available in 18/22 patients: in all of them mitochondrial abnormalities were present. Eighty six percent had mutations in mtDNA coding for tRNA lysine. In most of patients, lipomas were localized along the cervical-cranial-thoracic region. In 68% of the patients were distributed symmetrically. Only two patients had lipomas in a single anatomical site (1 in right arm and 1 in gluteus maximum). MSL is often overlooked by clinicians in patients with mitochondrial diseases where the clinical picture could be dominated by a severe multi-systemic involvement. Our data confirmed that MSL is a rare sign of mitochondrial disease with a strong association between multiple lipomas and lysine tRNA mutations. MSL could be considered, even if rare, a red flag for mitochondrial disorders, even in patients with an apparently isolated MSL.
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http://dx.doi.org/10.3389/fneur.2019.00160DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6402385PMC
February 2019

Assessment of disease progression in dysferlinopathy: A 1-year cohort study.

Neurology 2019 Jan 9. Epub 2019 Jan 9.

From the John Walton Muscular Dystrophy Research Centre (U.M., M.K.J., A.G.M., R.F.-T., M.E., K.B., R.M.L., H.H., H.L., K.B., V.S.), Newcastle University and Newcastle Hospitals NHS Foundation Trust, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Central Parkway, Newcastle Upon Tyne, UK; Center for Translational Science (M.J., J.F., A. Cnaan), Division of Biostatistics and Study Methodology, Cooperative International Neuromuscular Research Group (T.D., B.D.), and Department of Neurology (D.X.B.-G.), Children's National Health System; Pediatrics, Epidemiology and Biostatistics (M.J., A. Cnaan), George Washington University, Washington, DC; Neuromuscular Area (R.F.-T.), Biodonostia Health Research Institute, Neurology Service, Donostia University Hospital, Donostia-San Sebastian, Spain; Jain Foundation (L.E.R., P.M.), Seattle, WA; Magnetic Resonance Centre (A.M.B.), Institute of Cellular Medicine, Newcastle University, Newcastle Upon Tyne, UK; AIM & CEA NMR Laboratory (P.G.C.), Institute of Myology, Pitié-Salpêtrière University Hospital, 47-83, Paris, France; Research Institute at Nationwide Children's Hospital (L.P.L., L.A., K.M.B., J.R.M.), The Ohio State University, Columbus; Institute for Neuroscience and Muscle Research (K.R., M. Hutchence, K.J.J.), Children's Hospital at Westmead, University of Sydney, Australia; Lucile Salter Packard Children's Hospital at Stanford (T.D.), 24349, Neurology, Palo Alto, CA; Physical Medicine and Rehabilitation (E.M.-M., I.P.-H.), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Neuroscience Institute (S.H., M.S., E.B., S. Sparks), Carolinas Neuromuscular/ALS-MDA Center, Carolinas HealthCare System, Charlotte, NC; Department of Physical Rehabilitation (A.A., C. Sakamoto, T.T., H.Y.), National Center Hospital, National Center of Neurology and Psychiatry, Tokyo, Japan; Institut de Myologie (A. Canal, G.O., V.D., J.-Y.H., T.S.), AP-HP, GH Pitié-Salpêtrière, Paris, France; Neurorehabilitation Unit (J.B.M.), Rehabilitation Hospital Universitario Virgen del Rocío Sevilla; Neurophysiotherapy Department (N.S.-A.P.), Hospital Universitario Virgen del Rocío, Seville, Spain; Friedrich-Baur-Institute (S. Thiele, S.K., O.S.-K. M.C.W.), Department of Neurology, Ludwig-Maximilians-University of Munich, Germany; Department of Neurology (C. Siener, J.S., J.M.F., M. Harms, A.P.), Washington University School of Medicine, St. Louis, MO; Centre de Reference des Maladies Neuromusculaires PACA Réunion Rhone Alpes (B.V., E.S.-C.), Hopital de la Timone, Aix-Marseille Université, France; ELAN-PHYSIO (J.P., E.M.), Praxis für Physiotherapie Maron; Charite Muscle Research Unit (U.G., S. Spuler), Experimental and Clinical Research Center, a joint cooperation of the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine, Berlin, Germany; Department of Neurology and Neurological Sciences (C.T.R., J.W.D.), Stanford University School of Medicine, CA; NIH (D.X.B.-G.), Bethesda, MD; Neuromuscular Unit (C.P.), Department of Neurology, Hospital U. Virgen del Rocío/Instituto de Biomedicina de Sevilla, Spain; Department of Neurology (S. Takeda, M.M.-Y.), National Center Hospital, National Center of Neurology and Psychiatry, Tokyo, Japan; Centro de Investigación Biomédica en Red en Enfermedades Raras (J.D.-M.); Neuromuscular Disorders Unit (J.D.-M.), Neurology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; and Department of Neuroscience (L.B., C. Semplicini, E.P.), University of Padova, Italy.

Objective: To assess the ability of functional measures to detect disease progression in dysferlinopathy over 6 months and 1 year.

Methods: One hundred ninety-three patients with dysferlinopathy were recruited to the Jain Foundation's International Clinical Outcome Study for Dysferlinopathy. Baseline, 6-month, and 1-year assessments included adapted North Star Ambulatory Assessment (a-NSAA), Motor Function Measure (MFM-20), timed function tests, 6-minute walk test (6MWT), Brooke scale, Jebsen test, manual muscle testing, and hand-held dynamometry. Patients also completed the ACTIVLIM questionnaire. Change in each measure over 6 months and 1 year was calculated and compared between disease severity (ambulant [mild, moderate, or severe based on a-NSAA score] or nonambulant [unable to complete a 10-meter walk]) and clinical diagnosis.

Results: The functional a-NSAA test was the most sensitive to deterioration for ambulant patients overall. The a-NSAA score was the most sensitive test in the mild and moderate groups, while the 6MWT was most sensitive in the severe group. The 10-meter walk test was the only test showing significant change across all ambulant severity groups. In nonambulant patients, the MFM domain 3, wrist flexion strength, and pinch grip were most sensitive. Progression rates did not differ by clinical diagnosis. Power calculations determined that 46 moderately affected patients are required to determine clinical effectiveness for a hypothetical 1-year clinical trial based on the a-NSAA as a clinical endpoint.

Conclusion: Certain functional outcome measures can detect changes over 6 months and 1 year in dysferlinopathy and potentially be useful in monitoring progression in clinical trials.

Clinicaltrialsgov Identifier: NCT01676077.
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http://dx.doi.org/10.1212/WNL.0000000000006858DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6369904PMC
January 2019

The clinical spectrum of -related myopathy.

Neurology 2018 10 26;91(17):e1629-e1641. Epub 2018 Sep 26.

From the Neuromuscular Center (C.S., C.B., L.B., B.P., F.G., S.V., B.F.G., G.S., E.P.), Department of Neurosciences, and Departments of Cardiac, Thoracic and Vascular Sciences (M.P., C.C.), Biomedical Sciences (G.M., S.C.E.T.), and Medicine (R.S.), Section of Radiology, University of Padova, Italy; Dubowitz Neuromuscular Centre (Developmental Neuroscience Programme) (F.C.), UCL Great Ormond Street Institute of Child Health, University College London, UK; Neuromuscular and Rare Disease Unit (I.C., M.M.), Department of Neuroscience, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan; Department of Biomedical and Neuromotor Sciences (G.C., V.P.), University of Bologna; and CNR Institute of Neuroscience (S.C.E.T.), Padova, Italy.

Objective: To identify and characterize patients with calsequestrin 1 ()-related myopathy.

Methods: Patients selected according to histopathologic features underwent genetic screening. mutated patients were clinically evaluated and underwent muscle MRI. Vacuole morphology and vacuolated fiber type were characterized.

Results: Twenty-two -mutated patients (12 families) were identified, 21 sharing the previously described founder mutation (p.Asp244Gly) and 1 with the p.Gly103Asp mutation. Patients usually presented in the sixth decade with exercise intolerance and myalgias and later developed mild to moderate, slowly progressive proximal weakness with quadriceps atrophy and scapular winging. Muscle MRI (n = 11) showed a recurrent fibrofatty substitution pattern. Three patients presented subclinical cardiac abnormalities. Muscle histopathology in patients with p.Asp244Gly showed vacuoles in type II fibers appearing empty in hematoxylin-eosin, Gomori, and nicotinamide adenine dinucleotide (NADH) tetrazolium reductase stains but strongly positive for sarcoplasmic reticulum proteins. The muscle histopathology of p.Gly103Asp mutation was different, showing also NADH-positive accumulation consistent with tubular aggregates.

Conclusions: We report the clinical and molecular details of the largest cohort of -mutated patients. A possible heart involvement is presented, further expanding the phenotype of the disease. One mutation is common due to a founder effect, but other mutations are possible. Because of a paucity of symptoms, it is likely that mutations may remain undiagnosed if a muscle biopsy is not performed.
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http://dx.doi.org/10.1212/WNL.0000000000006387DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6205688PMC
October 2018

Upper limb function in Duchenne muscular dystrophy: 24 month longitudinal data.

PLoS One 2018 20;13(6):e0199223. Epub 2018 Jun 20.

Department of Neurosciences, University of Padua, Padua, Italy.

The aim of the study was to establish 24 month changes in upper limb function using a revised version of the performance of upper limb test (PUL 2.0) in a large cohort of ambulant and non-ambulant boys with Duchenne muscular dystrophy and to identify possible trajectories of progression. Of the 187 patients studied, 87 were ambulant (age range: 7-15.8 years), and 90 non-ambulant (age range: 9.08-24.78). The total scores changed significantly over time (p<0.001). Non-ambulant patients had lower total scores at baseline (mean 19.7) when compared to the ambulant ones (mean 38.4). They also had also a bigger decrease in total scores over 24 months compared to the ambulant boys (4.36 vs 2.07 points). Multivariate model analysis showed that the Performance of Upper Limb changes reflected the entry level and ambulation status, that were independently associated to the slope of Performance of Upper Limb changes. This information will be of help both in clinical practice and at the time of designing clinical trials.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0199223PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6010252PMC
April 2019
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