Findings from the Longitudinal CINRG Becker Natural History Study.

Background: Becker muscular dystrophy is an X-linked, genetic disorder causing progressive degeneration of skeletal and cardiac muscle, with a widely variable phenotype.

Objective: A 3-year, longitudinal, prospective dataset contributed by patients with confirmed Becker muscular dystrophy was analyzed to characterize the natural history of this disorder. A better understanding of the natural history is crucial to rigorous therapeutic trials.

Association between neurodevelopmental impairments and motor function in Duchenne muscular dystrophy.

Objective: We explored various prognostic factors of motor outcomes in corticosteroid-naive boys with Duchenne Muscular Dystrophy (DMD).

Methods: The associations between parent-reported neurodevelopmental concerns (speech delay, speech and language difficulties (SLD), and learning difficulties), DMD mutation location, and motor outcomes (6-minute walk distance (6MWD), North Star Ambulatory Assessment (NSAA) total score, 10-meter walk/run velocity, and rise from floor velocity) were studied in 196 corticosteroid-naive boys from ages 4 to less than 8 years.

Results: Participants with SLD walked 25.

Longitudinal motor function in proximal versus distal DMD pathogenic variants.

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.

Dystrophic muscle distribution in late-stage muscular dystrophy.

There is scant information about the comprehensive distribution of dystrophic muscles in muscular dystrophy. Despite different clinical presentations of muscular dystrophy, a recent multi-center study concluded that phenotypic distribution of dystrophic muscles is independent of clinical phenotype and suggested that there is a common pattern of involved muscles. To evaluate this possibility, the present case report used cadaveric dissection to determine the whole-body distribution of fat-infiltrated, dystrophic muscles from a 72-year-old white male cadaver with adult-onset, late-stage muscular dystrophy.

Multi-Omics Identifies Circulating miRNA and Protein Biomarkers for Facioscapulohumeral Dystrophy.

The development of therapeutics for muscle diseases such as facioscapulohumeral dystrophy (FSHD) is impeded by a lack of objective, minimally invasive biomarkers. Here we identify circulating miRNAs and proteins that are dysregulated in early-onset FSHD patients to develop blood-based molecular biomarkers. Plasma samples from clinically characterized individuals with early-onset FSHD provide a discovery group and are compared to healthy control volunteers.

Longitudinal Evaluation of Working Memory in Duchenne Muscular Dystrophy.

The developmental maturation of forward and backward digit spans-indices of working memory-in boys with nonsense (nm) Duchenne muscular dystrophy (DMD) (nmDMD) was assessed using prospective, longitudinal data. Methods: Fifty-five boys of the 57 subjects with genetically confirmed nmDMD-who were from the placebo arm of a 48-week-long phase 2b clinical trial-were evaluated. Forward and backward digit spans were obtained every 12 weeks for a total of five assessments in all study subjects.

The CINRG Becker Natural History Study: Baseline characteristics.

We performed an observational, natural history study of males with in-frame dystrophin gene deletions causing Becker muscular dystrophy (BMD). A prospective natural history study collected longitudinal medical, strength, and timed function assessments. Eighty-three participants with genetically confirmed BMD were enrolled (age range 5.

The Dystrophinopathies.

Purpose Of Review: The dystrophinopathies are among the most common neuromuscular conditions, and they include Duchenne and Becker muscular dystrophies. This article reviews the epidemiology, clinical manifestations, genetic cause, management, and new and emerging therapies for this condition.

Recent Findings: New studies have highlighted how oral corticosteroids have changed the natural history of the disease, prolonging ambulation in boys with Duchenne muscular dystrophy and reducing the risk of developing scoliosis and subsequent surgical correction, improving cardiac health, and increasing long-term survival.

Relationships between mutations and neurodevelopment in dystrophinopathy.

Objective: We performed a prospective, cross-sectional analysis of neurodevelopmental concerns and psychosocial adjustment in relation to mutations in young steroid-naive boys with dystrophinopathy.

Methods: We evaluated 196 steroid-naive boys with dystrophinopathy who were enrolled in the Finding the Optimal Regimen for Duchenne Muscular Dystrophy trial. The neurodevelopmental concerns and psychosocial adjustment challenges were analyzed in relation to mutation.

The NIH Toolbox for cognitive surveillance in Duchenne muscular dystrophy.

Objective: We performed a prospective, cross-sectional cognitive assessment in subjects with Duchenne Muscular Dystrophy (DMD) and their biological mothers.

Methods: Thirty subjects with out-of-frame mutations in the dystrophin (DMD) gene, and 25 biological mothers were evaluated using the National Institutes of Health Toolbox Cognition Battery (NIHTB-CB). A parent completed the Behavior Rating Inventory of Executive Functioning (BRIEF), a standardized rating scale of executive functioning, for their child.

Discovery of potential urine-accessible metabolite biomarkers associated with muscle disease and corticosteroid response in the mdx mouse model for Duchenne.

Urine is increasingly being considered as a source of biomarker development in Duchenne Muscular Dystrophy (DMD), a severe, life-limiting disorder that affects approximately 1 in 4500 boys. In this study, we considered the mdx mice-a murine model of DMD-to discover biomarkers of disease, as well as pharmacodynamic biomarkers responsive to prednisolone, a corticosteroid commonly used to treat DMD. Longitudinal urine samples were analyzed from male age-matched mdx and wild-type mice randomized to prednisolone or vehicle control via liquid chromatography tandem mass spectrometry.

Neurodevelopmental Needs in Young Boys with Duchenne Muscular Dystrophy (DMD): Observations from the Cooperative International Neuromuscular Research Group (CINRG) DMD Natural History Study (DNHS).

Introduction: Duchenne muscular dystrophy (DMD) is the most common X-linked neuromuscular condition manifested by progressive skeletal muscle weakness, cardiopulmonary involvement and cognitive deficits. Neurodevelopmental symptoms and signs are under-appreciated in this population despite the recognition that cognition has a major impact on quality-of-life. We describe the neurodevelopmental needs in a large cohort of young boys with DMD from the DMD Natural History Study (DNHS).

The relationship between deficit in digit span and genotype in nonsense mutation Duchenne muscular dystrophy.

Objective: To evaluate the relationship between deficit in digit span and genotype in nonsense mutation (nm) Duchenne muscular dystrophy (DMD) (nmDMD).

Methods: We investigated the relationship between normalized digit-span forward (d-sf) and digit-span backward (d-sb) scores to the location of nmDMD mutations in 169 participants ≥5 to ≤20 years who participated in a phase 2b clinical trial. Because alternative promoters are found upstream of exons 30, 45, and 63, we correlated d-sf and d-sb to the specific nmDMD mutation location.

Recruitment & retention program for the NeuroNEXT SMA Biomarker Study: Super Babies for SMA!

Background/aims: Recruitment and retention of research participants are challenging and critical components of successful clinical trials and natural history studies. Infants with spinal muscular atrophy (SMA) have been a particularly challenging population to study due to their fragile and complex medical issues, poor prognosis and, until 2016, a lack of effective therapies. Recruitment of healthy infants into clinical trials and natural history studies is also challenging and sometimes assumed to not be feasible.

A checklist for clinical trials in rare disease: obstacles and anticipatory actions-lessons learned from the FOR-DMD trial.

Background: Trials in rare diseases have many challenges, among which are the need to set up multiple sites in different countries to achieve recruitment targets and the divergent landscape of clinical trial regulations in those countries. Over the past years, there have been initiatives to facilitate the process of international study set-up, but the fruits of these deliberations require time to be operationally in place. FOR-DMD (Finding the Optimum Steroid Regimen for Duchenne Muscular Dystrophy) is an academic-led clinical trial which aims to find the optimum steroid regimen for Duchenne muscular dystrophy, funded by the National Institutes of Health (NIH) for 5 years (July 2010 to June 2015), anticipating that all sites (40 across the USA, Canada, the UK, Germany and Italy) would be open to recruitment from July 2011.

The Relationship Between Bone Mineral Density and Cardiovascular Function in Duchenne Muscular Dystrophy: A Retrospective Cohort Study.

Introduction: Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder that causes progressive skeletal and cardiac muscle weakness in boys. Cardiac dysfunction is a frequent cause of death in DMD. Glucocorticoids are the standard of care in DMD.

A multinational study on motor function in early-onset FSHD.

Objectives: To investigate motor function associations with age, sex, and repeats among participants with early-onset facioscapulohumeral muscular dystrophy (FSHD) type 1 as defined by weakness onset before 10 years of age.

Methods: We collected standardized motor assessments, including manual muscle testing (MMT), quantitative muscle testing, functional motor evaluations, and clinical severity scores (CSSs), at 12 Cooperative International Neuromuscular Research Group centers. To measure associations, we used linear regression models adjusted for sex, evaluation age, age at onset of weakness, and repeats.

Natural history of infantile-onset spinal muscular atrophy.

Objective: Infantile-onset spinal muscular atrophy (SMA) is the most common genetic cause of infant mortality, typically resulting in death preceding age 2. Clinical trials in this population require an understanding of disease progression and identification of meaningful biomarkers to hasten therapeutic development and predict outcomes.

Methods: A longitudinal, multicenter, prospective natural history study enrolled 26 SMA infants and 27 control infants aged <6 months.

Cytoplasmic body pathology in severe ACTA1-related myopathy in the absence of typical nemaline rods.

Mutations in ACTA1 cause a group of myopathies with expanding clinical and histopathological heterogeneity. We describe three patients with severe ACTA1-related myopathy who have muscle fiber cytoplasmic bodies but no classic nemaline rods. Patient 1 is a five-year-old boy who presented at birth with severe weakness and respiratory failure, requiring mechanical ventilation.

Baseline results of the NeuroNEXT spinal muscular atrophy infant biomarker study.

Objective: This study prospectively assessed putative promising biomarkers for use in assessing infants with spinal muscular atrophy (SMA).

Methods: This prospective, multi-center natural history study targeted the enrollment of SMA infants and healthy control infants less than 6 months of age. Recruitment occurred at 14 centers within the NINDS National Network for Excellence in Neuroscience Clinical Trials (NeuroNEXT) Network.

Fatal human herpesvirus 6-associated encephalitis in two boys with underlying POLG mitochondrial disorders.

Background: Human herpesvirus 6 is a significant cause of the febrile illness roseola infantum in young children. Infection with human herpesvirus 6 typically causes a self-limited febrile illness but occasionally is associated with central nervous system manifestations, including febrile seizures and encephalitis. Host factors associated with severe manifestations of human herpesvirus 6-associated neurological disease remain poorly characterized.

Magnetic resonance angiography-defined intracranial vasculopathy is associated with silent cerebral infarcts and glucose-6-phosphate dehydrogenase mutation in children with sickle cell anaemia.

Silent cerebral infarct (SCI) is the most commonly recognized cause of neurological injury in sickle cell anaemia (SCA). We tested the hypothesis that magnetic resonance angiography (MRA)-defined vasculopathy is associated with SCI. Furthermore, we examined genetic variations in glucose-6-phosphate dehydrogenase (G6PD) and HBA (α-globin) genes to determine their association with intracranial vasculopathy in children with SCA.