Vacuolar myopathy with monoclonal gammopathy and stiffness (VAMMGAS).

Background: Monoclonal gammopathy (MG) has been reported in association with numerous neurological disorders but the spectrum of MG-associated myopathies remains poorly described.

Objective: To report a newly acquired myopathy associated with MG.

Methods: Three adult patients with the same phenotype from two French referral centers were prospectively analyzed.

SMCHD1 genetic variants in type 2 facioscapulohumeral dystrophy and challenges in predicting pathogenicity and disease penetrance.

The molecular diagnosis of type 1 facioscapulohumeral muscular dystrophy (FSHD1) relies on the detection of a shortened D4Z4 array at the 4q35 locus. Until recently, the diagnosis of FSHD2 relied solely on the absence of a shortened D4Z4 allele in clinically affected patients. It is now established that most FSHD2 cases carry a heterozygous variant in the SMCHD1 gene.

Spinal muscular atrophy is also a disorder of spermatogenesis.

Background: Spinal muscular atrophy (SMA) patients benefit from pre-mRNA splicing modifiers targeting the SMN2 gene, which aims to increase functional SMN production. The animal toxicity affecting spermatogenesis associated with one such treatment raised questions about male SMA patients' spermatogenesis.

Methods: This descriptive, cross-sectional study was conducted from June 2022 to July 2023.

Electrophysiological Monitoring of Asymptomatic Transthyretin Mutation Carriers.

Introduction/aims: It is imperative to screen asymptomatic carriers of transthyretin (TTR) mutations to initiate treatment early. The protocol for repeated electrodiagnostic (EDX) assessments over time lacks standardization. Our aim was to report the electrophysiological evolution of a cohort of asymptomatic carriers and to determine which biomarkers were most sensitive to change.

Real-life experience with disease-modifying drugs in hereditary transthyretin amyloid polyneuropathy: A clinical and electrophysiological appraisal.

Introduction: New treatments have dramatically improved the prognosis for Hereditary Transthyretin Amyloid Polyneuropathy (ATTRv-PN). However, there is a lack of routine follow-up studies outside of therapeutic trials. Our aim was to report the long-term clinical and electrophysiological evolution of a cohort of ATTRv-PN patients and to determine which biomarkers are most sensitive to change.

-related myopathies: clinical, myopathological and genotypic spectrum in a multicentre French cohort.

Background: Myosin heavy chain 7 ()-related myopathies (-RMs) are a group of muscle disorders linked to pathogenic variants in the gene, encoding the slow/beta-cardiac myosin heavy chain, which is highly expressed in skeletal muscle and heart. The phenotype is heterogeneous including distal, predominantly axial or scapuloperoneal myopathies with variable cardiac involvement.

Methods: We retrospectively analysed the clinical, muscle MRI, genetic and myopathological features of 57 patients.

Recommendations of an expert group for the cardiac assessment of non-dystrophic myotonia adult patients treated with mexiletine.

Mexiletine (NaMuscla™) is indicated for the symptomatic treatment of myotonia in adults with non-dystrophic myotonia. A cardiac assessment is required as mexiletine may have a pro-arrhythmic effect. Long-term safety data supporting the use of mexiletine in patients with non-dystrophic myotonia combined with the extensive clinical experience of an expert group resulted in creation of an algorithm for cardiac monitoring of patients treated with mexiletine.

Electrophysiological features of the peripheral neuropathy in patients with pathologic biallelic RFC1 repeat expansions.

Introduction/aims: Cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) is caused by RFC1 expansions. Sensory neuronopathy, polyneuropathy, and involvement of motor, autonomic, and cranial nerves have all been described with RFC1 expansions. We aimed to describe the electrodiagnostic features of patients with RFC1 expansions through multimodal electrophysiological investigations.

Real-world data of in-hospital administration of alglucosidase alfa in French patients with Pompe disease: results from the National Claims Database.

Introduction: Pompe disease is caused by a rare biallelic mutation in the GAA gene resulting in acid α-glucosidase deficiency and glycogen accumulation.

Aim: We analyzed hospital admissions associated with the administration of Myozyme®, utilizing the French hospital discharge database, known in France as the Programme de Médicalisation des Systèmes d'Information (PMSI), which comprehensively captures all hospital activity within the country.

Methods: In this observational study, we examined hospitalization records from April 4, 2012, to December 31, 2019, within the PMSI database, focusing on admissions where Myozyme® was administered.

French National Protocol for diagnosis and care of facioscapulohumeral muscular dystrophy (FSHD).

Facioscapulohumeral muscular dystrophy (FSHD) is one of the most common genetically inherited myopathies in adults. It is characterized by incomplete penetrance and variable expressivity. Typically, FSHD patients display asymmetric weakness of facial, scapular, and humeral muscles that may progress to other muscle groups, particularly the abdominal and lower limb muscles.

Expert opinion on mexiletine treatment in adult patients with myotonic dystrophy.

In France, mexiletine - a class I antiarrhythmic drug - can be prescribed for the symptomatic treatment of myotonia of the skeletal muscles in adult patients with myotonic dystrophy under a compassionate use programme. Mexiletine is used according to its summary of product characteristics, which describes its use for myotonia treatment in adult patients with non-dystrophic myotonia, a different neuromuscular condition without cardiac involvement. A cardiac assessment is required prior to initiation and throughout treatment due to potential proarrhythmic effects.

Phenotype variability and natural history of X-linked myopathy with excessive autophagy.

Objective: X-linked myopathy with excessive autophagy (XMEA) linked to the VMA21 gene leads to autophagy failure with progressive vacuolation and atrophy of skeletal muscles. Current knowledge of this rare disease is limited. Our objective was to define the clinical, radiological, and natural history of XMEA.

Post-hoc Nonparametric Analysis of Forced Vital Capacity in the COMET Trial Demonstrates Superiority of Avalglucosidase Alfa vs Alglucosidase Alfa.

In the COMET trial of patients with late-onset Pompe disease, greater improvement in upright forced vital capacity (FVC) % predicted was observed with avalglucosidase alfa (AVA) vs alglucosidase alfa (ALGLU) (estimated treatment difference: 2.43%). The pre-specified mixed model repeated measures (MMRM) analysis demonstrated non-inferiority of AVA (P = 0.

Retrospective clinical and genetic analysis of COL6-RD patients with a long-term follow-up at a single French center.

Collagen type VI-related dystrophies (COL6-RD) are rare diseases with a wide phenotypic spectrum ranging from severe Ullrich's congenital muscular dystrophy Ullrich congenital muscular dystrophy to much milder Bethlem myopathy Both dominant and recessive forms of COL6-RD are caused by pathogenic variants in three collagen VI genes (, and ). The prognosis of these diseases is variable and difficult to predict during early disease stages, especially since the genotype-phenotype correlation is not always clear. For this reason, studies with long-term follow-up of patients with genetically confirmed COL6-RD are still needed.