Background: Autosomal recessive inherited pathogenetic variants in the histidine triad nucleotide-binding protein 1 () gene are responsible for an axonal Charcot-Marie-Tooth neuropathy associated with neuromyotonia, a phenomenon resulting from peripheral nerve hyperexcitability that causes a spontaneous muscle activity such as persistent muscle contraction, impaired relaxation and myokymias.
Methods: Herein, we describe two brothers in whom biallelic variants were identified following a multidisciplinary approach.
Results: The younger brother came to our attention for clinical evaluation of moderate intellectual disability, language developmental delay, and some behavioral issues.
Sleep disorders have been poorly described in congenital (CDM) and childhood (ChDM) myotonic dystrophy despite being highly burdensome. The aims of this study were to explore sleep disorders in a cohort of Italian CDM and ChDM and to assess their association with motor and respiratory function and disease-specific cognitive and behavioral assessments. This was an observational multicenter study.
View Article and Find Full Text PDFAim: To investigate the timing of type 1 myotonic dystrophy (DM1) diagnosis in parents of affected children and describe children's perinatal characteristics and developmental outcomes.
Method: This was a descriptive case series of children with congenital myotonic dystrophy (CDM) and childhood-onset myotonic dystrophy (ChDM). Parental timing of DM1 diagnosis and the perinatal, motor, and cognitive outcomes of paediatric patients were recorded.
Hereditary spastic paraplegias (HSPs) are a genetically heterogeneous group of neurodegenerative disorders clinically characterized by progressive lower limb spasticity with pyramidal weakness. Around a dozen potential molecular mechanisms are recognized. Childhood HSP is a significant diagnostic challenge in clinical practice.
View Article and Find Full Text PDFBackground: Dilated cardiomyopathy (DCM) is a major complication of, and leading cause of mortality in Duchenne muscular dystrophy (DMD). Its severity, age at onset, and rate of progression display wide variability, whose molecular bases have been scarcely elucidated. Potential DCM-modifying factors include glucocorticoid (GC) and cardiological treatments, DMD mutation type and location, and variants in other genes.
View Article and Find Full Text PDFHereditary myopathies represent a clinically and genetically heterogeneous group of neuromuscular disorders, characterized by highly variable clinical presentations and frequently overlapping phenotypes with other neuromuscular disorders, likely influenced by genetic and environmental modifiers. Genetic testing is often challenging due to ambiguous clinical diagnosis. Here, we present the case of a family with clinical and Electromyography (EMG) features resembling a myotonia-like disorder in which Whole Exome Sequencing (WES) analysis revealed the co-segregation of two rare missense variants in and , genes previously associated with episodic ataxia 8 (EA8).
View Article and Find Full Text PDFBackground: KBG syndrome is caused by haploinsufficiency of and is characterised by macrodontia of upper central incisors, distinctive facial features, short stature, skeletal anomalies, developmental delay, brain malformations and seizures. The central nervous system (CNS) and skeletal features remain poorly defined.
Methods: CNS and/or skeletal imaging were collected from molecularly confirmed individuals with KBG syndrome through an international network.
Background: Congenital myopathies are a group of clinically, genetically, and histologically heterogeneous diseases caused by mutations in a large group of genes. One of these is , which is recognized as the cause of Dihydropyridine Receptor Congenital Myopathy.
Methods: To better characterize the phenotypic spectrum of myopathy, we conducted a systematic review of cases in the literature through three electronic databases following the PRISMA guidelines.
Objective: To define the prevalence of variants in collagen VI genes through a next-generation sequencing (NGS) approach in undiagnosed patients with suspected neuromuscular disease and to propose a diagnostic flowchart to assess the real pathogenicity of those variants.
Methods: In the past five years, we have collected clinical and molecular information on 512 patients with neuromuscular symptoms referred to our center. To pinpoint variants in COLVI genes and corroborate their real pathogenicity, we sketched a multistep flowchart, taking into consideration the bioinformatic weight of the gene variants, their correlation with clinical manifestations and possible effects on protein stability and expression.
Genetic modifiers of Duchenne muscular dystrophy (DMD) are variants located in genes different from the disease-causing gene DMD, but associated with differences in disease onset, progression, or response to treatment. Modifiers described so far have been tested mainly for associations with ambulatory function, while their effect on upper limb function, which is especially relevant for quality of life and independence in non-ambulatory patients, is unknown. We tested genotypes at several known modifier loci (SPP1, LTBP4, CD40, ACTN3) for association with Performance Upper Limb version 1.
View Article and Find Full Text PDFMutations in the RYR1 gene, encoding ryanodine receptor 1 (RyR1), are a well-known cause of Central Core Disease (CCD) and Multi-minicore Disease (MmD). We screened a cohort of 153 patients carrying an histopathological diagnosis of core myopathy (cores and minicores) for RYR1 mutation. At least one RYR1 mutation was identified in 69 of them and these patients were further studied.
View Article and Find Full Text PDFThe main consequence of the COVID-19 pandemic has been to increase the distance between patients and their doctors and to limit the opportunities to compare experiences and clinical cases in the medical community. Based on this, we adopted a strategy to create networks with the ambition to break down these distances and to unify the process of care and management. Here we report the results and perspectives of our efforts and studies.
View Article and Find Full Text PDFInherited muscular dystrophies and congenital myopathies present in early childhood with progressive muscle weakness, determining severe motor limitations. Active surveillance and management of associated complications have improved ambulation, function, quality of life and life expectancy. The need for repeatable, objective and quantitative measures to monitor the clinical course of the disease is a current issue, particularly in the new era where new flows of therapies are proposed to the patients.
View Article and Find Full Text PDFMuscle MRI has an increasing role in diagnosis of inherited neuromuscular diseases, but no features are known which reliably differentiate myopathic and neurogenic conditions. Using patients presenting with early onset distal weakness, we aimed to identify an MRI signature to distinguish myopathic and neurogenic conditions. We identified lower limb MRI scans from patients with either genetically (n = 24) or clinically (n = 13) confirmed diagnoses of childhood onset distal myopathy or distal spinal muscular atrophy.
View Article and Find Full Text PDFBackground: Monoallelic variants in the KIF1A gene are associated with a large set of clinical phenotypes including neurodevelopmental and neurodegenerative disorders, underpinned by a broad spectrum of central and peripheral nervous system involvement.
Methods: In a multicenter study conducted in patients presenting spastic gait or complex neurodevelopmental disorders, we analyzed the clinical, genetic and neuroradiological features of 28 index cases harboring heterozygous variants in KIF1A. We conducted a literature systematic review with the aim to comparing our findings with previously reported KIF1A-related phenotypes.