Genomic reanalysis of a pan-European rare-disease resource yields new diagnoses.

Genetic diagnosis of rare diseases requires accurate identification and interpretation of genomic variants. Clinical and molecular scientists from 37 expert centers across Europe created the Solve-Rare Diseases Consortium (Solve-RD) resource, encompassing clinical, pedigree and genomic rare-disease data (94.5% exomes, 5.

Expanding the Molecular Genetic Landscape of Dystrophinopathies and Associated Phenotypes.

: X-linked dystrophinopathies are a group of neuromuscular diseases caused by pathogenic variants in the gene (MIM *300377). Duchenne muscular dystrophy (DMD; MIM #310200) is the most common inherited muscular dystrophy. : We screened datasets of 403 male, genetically confirmed X-linked dystrophinopathy patients and identified 13 pathogenic variants of the gene that have not been described in the literature thus far.

Sensory neuropathy in patients with Pompe disease: a case series in Iran.

Background: Pompe disease is a glycogen storage disease primarily affecting striated muscles. Despite its main manifestation in muscles, patients with Pompe disease may exhibit non-muscle symptoms, such as hearing loss, suggesting potential involvement of sensory organs or the nervous system due to glycogen accumulation.

Aims: This study aimed to evaluate the presence of concomitant small and large fiber neuropathy in patients with Pompe disease.

Mortality Trends and Causes of Death in Myotonic Dystrophy Type 1 Patients From the UK Clinical Practice Research Datalink.

Introduction/aim: Patients with myotonic dystrophy type1 (DM1) have reduced lifespan. This study aimed to quantify mortality risks, and evaluate causes and time trends in DM1.

Methods: We identified 1021 DM1 patients and 15,104 matched DM1-free controls from the United Kingdom (UK) Clinical Practice Research Datalink.

Development of a riboflavin-responsive model of riboflavin transporter deficiency in zebrafish.

Riboflavin transporter deficiency (RTD) is a rare and progressive neurodegenerative disease resulting from the disruption of RFVT2- and RFVT3- mediated riboflavin transport caused by biallelic mutations in SLC52A2 and SLC52A3, respectively. The resulting impaired mitochondrial metabolism leads to sensorimotor neurodegeneration and symptoms including muscle weakness, respiratory difficulty, and sensorineural deafness. Although over 70% of patients with RTD improve following high-dose riboflavin supplementation, remaining patients either stabilise or continue to deteriorate.

Diagnosing missed cases of spinal muscular atrophy in genome, exome, and panel sequencing datasets.

Purpose: We set out to develop a publicly available tool that could accurately diagnose spinal muscular atrophy (SMA) in exome, genome or panel sequencing datasets aligned to a GRCh37, GRCh38, or T2T reference genome.

Methods: The SMA Finder algorithm detects the most common genetic causes of SMA by evaluating reads that overlap the c.840 position of the SMN1 and SMN2 paralogs.

Ion Mobility QTOF-MS Untargeted Lipidomics of Human Serum Reveals a Metabolic Fingerprint for GNE Myopathy.

GNE myopathy, also known as hereditary inclusion body myopathy (HIBM), is a rare genetic muscle disorder marked by a gradual onset of muscle weakness in young adults. GNE myopathy (GNEM) is caused by bi-allelic variants in the UDP--acetylglucosamine 2-epimerase (UDP-GlcNAc 2-epimerase)/-acetylmannosamine kinase (ManNAc kinase) gene (), clinically resulting in the loss of ambulation within 10-20 years from the onset of the initial symptoms. The disease's mechanism is poorly understood and non-invasive biomarkers are lacking, hindering effective therapy development.

Brain malformations and seizures by impaired chaperonin function of TRiC.

Malformations of the brain are common and vary in severity, from negligible to potentially fatal. Their causes have not been fully elucidated. Here, we report pathogenic variants in the core protein-folding machinery TRiC/CCT in individuals with brain malformations, intellectual disability, and seizures.

A Deficiency in Glutamine-Fructose-6-Phosphate Transaminase 1 (Gfpt1) in Skeletal Muscle Results in Reduced Glycosylation of the Delta Subunit of the Nicotinic Acetylcholine Receptor (AChRδ).

The neuromuscular junction (NMJ) is the site where the motor neuron innervates skeletal muscle, enabling muscular contraction. Congenital myasthenic syndromes (CMS) arise when mutations in any of the approximately 35 known causative genes cause impaired neuromuscular transmission at the NMJ, resulting in fatigable muscle weakness. A subset of five of these CMS-causative genes are associated with protein glycosylation.

Biallelic PTPMT1 variants disrupt cardiolipin metabolism and lead to a neurodevelopmental syndrome.

Primary mitochondrial diseases (PMDs) are among the most common inherited neurological disorders. They are caused by pathogenic variants in mitochondrial or nuclear DNA that disrupt mitochondrial structure and/or function, leading to impaired oxidative phosphorylation (OXPHOS). One emerging subcategory of PMDs involves defective phospholipid (PL) metabolism.

GNE Myopathy: Genotype - Phenotype Correlation and Disease Progression in an Indian Cohort.

Introduction: GNE myopathy is a rare slowly progressive adult-onset distal myopathy with autosomal recessive inheritance. It has distinctive features of quadriceps sparing with preferential anterior tibial involvement. Most patients eventually become wheelchair bound by 10-20 years after onset.

HNRNPA1 de novo Variant Associated with Early Childhood Onset, Rapidly Progressive Generalized Myopathy.

HNRNPA1 variants are known to cause degenerative motoneuron and muscle diseases which manifests in middle age or later. We report on a girl with early childhood onset, rapidly progressive generalized myopathy including ultrastructural findings in line with a proteinopathy. Proteomics of patient-derived muscle and combined screening of genomic data for copy number variations identified a HNRNPA1 de novo intragenic deletion as causative for the phenotype.

Direct and indirect costs of idiopathic inflammatory myopathies in adults: A systematic review.

Idiopathic inflammatory myopathies (IIMs) are rare disorders characterized by inflammation of skeletal muscle, which can result in fatty replacement of muscle, muscle atrophy, and subsequent weakness. Therapeutic advancements have improved clinical outcomes but impose an economic impact on healthcare systems. We aimed to summarize the direct and indirect costs associated with IIMs in a systematic review (PROSPERO Registration #CRD42023443143).

Advancing the Understanding of Vesicle-Associated Membrane Protein 1-Related Congenital Myasthenic Syndrome: Phenotypic Insights, Favorable Response to 3,4-Diaminopyridine, and Clinical Characterization of Five New Cases.

Background: Congenital myasthenic syndromes (CMS) are a group of inherited neuromuscular junction (NMJ) disorders arising from gene variants encoding diverse NMJ proteins. Recently, the VAMP1 gene, responsible for encoding the vesicle-associated membrane protein 1 (VAMP1), has been associated with CMS.

Methods: This study presents a characterization of five new individuals with VAMP1-related CMS, providing insights into the phenotype.

Unravelling undiagnosed rare disease cases by HiFi long-read genome sequencing.

Solve-RD is a pan-European rare disease (RD) research program that aims to identify disease-causing genetic variants in previously undiagnosed RD families. We utilised 10-fold coverage HiFi long-read sequencing (LRS) for detecting causative structural variants (SVs), single nucleotide variants (SNVs), insertion-deletions (InDels), and short tandem repeat (STR) expansions in extensively studied RD families without clear molecular diagnoses. Our cohort includes 293 individuals from 114 genetically undiagnosed RD families selected by European Rare Disease Network (ERN) experts.

E-Health & Innovation to Overcome Barriers in Neuromuscular Diseases. Report from the 3rd eNMD Congress: Pisa, Italy, 29-30 October 2021.

Neuromuscular diseases (NMDs), in their phenotypic heterogeneity, share quite invariably common issues that involve several clinical and socio-economical aspects, needing a deep critical analysis to develop better management strategies. From diagnosis to treatment and follow-up, the development of technological solutions can improve the detection of several critical aspects related to the diseases, addressing both the met and unmet needs of clinicians and patients. Among several aspects of the digital transformation of health and care, this congress expands what has been learned from previous congresses editions on applicability and usefulness of technological solutions in NMDs.

Partial loss of desmin expression due to a leaky splice site variant in the human DES gene is associated with neuromuscular transmission defects.

Recessive desminopathies are rare and often present as severe early-onset myopathy. Here we report a milder phenotype in three unrelated patients from southern India (2 M, 1F) aged 16, 21, and 22 years, who presented with childhood-onset, gradually progressive, fatigable limb-girdle weakness, ptosis, speech and swallowing difficulties, without cardiac involvement. Serum creatine kinase was elevated, and repetitive nerve stimulation showed decrement in all.

Predictors of Loss of Ambulation in Duchenne Muscular Dystrophy: A Systematic Review and Meta-Analysis.

Objective: The objective of this study was to describe predictors of loss of ambulation in Duchenne muscular dystrophy (DMD).

Methods: This systematic review and meta-analysis included searches of MEDLINE ALL, Embase, and the Cochrane Database of Systematic Reviews from January 1, 2000, to December 31, 2022, for predictors of loss of ambulation in DMD. Search terms included "Duchenne muscular dystrophy" as a Medical Subject Heading or free text term, in combination with variations of the term "predictor".

Safety and efficacy of losmapimod in facioscapulohumeral muscular dystrophy (ReDUX4): a randomised, double-blind, placebo-controlled phase 2b trial.

Background: Facioscapulohumeral muscular dystrophy is a hereditary progressive myopathy caused by aberrant expression of the transcription factor DUX4 in skeletal muscle. No approved disease-modifying treatments are available for this disorder. We aimed to assess the safety and efficacy of losmapimod (a small molecule that inhibits p38α MAPK, a regulator of DUX4 expression, and p38β MAPK) for the treatment of facioscapulohumeral muscular dystrophy.