Publications by authors named "Meganne Leach"

Biallelic pathogenic variants in the gene encoding nebulin (NEB) are a known cause of congenital myopathy. We present two brothers with congenital myopathy and compound heterozygous variants (NC_000002.12:g.

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Background And Objectives: Omigapil is a small molecule which inhibits the GAPDH-Siah1-mediated apoptosis pathway. Apoptosis is a pathomechanism underlying the congenital muscular dystrophy subtypes LAMA2-related dystrophy (LAMA2-RD) and COL6-related dystrophy (COL6-RD). Studies of omigapil in the (dy/dy) LAMA2-RD mouse model demonstrated improved survival, and studies in the (dy/dy) LAMA2-RD mouse model and the (Col6a1) COL6-RD mouse model demonstrated decreased apoptosis.

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Article Synopsis
  • Collagen VI-related dystrophies (COL6-RDs) include a range of conditions such as Ullrich congenital muscular dystrophy (UCMD), which features severe muscle weakness and respiratory issues, and Bethlem muscular dystrophy, which has milder and later-presenting symptoms.
  • Some patients with symptoms typical of COL6-RDs were previously undiagnosed until a deep intronic variant in COL6A1 was identified, leading to a severe form of UCMD in a cohort of 44 patients, except for one with a milder phenotype.
  • The study suggests that a new pseudoexon skipping therapy could effectively reduce the severity of UCMD symptoms by targeting the abnormal transcripts
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Biallelic pathogenic variants in the gene encoding nebulin () are a known cause of congenital myopathy. We present two individuals with congenital myopathy and compound heterozygous variants (NM_001271208.2: c.

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Purpose: We sought to delineate a multisystem disorder caused by recessive cysteine-rich with epidermal growth factor-like domains 1 (CRELD1) gene variants.

Methods: The impact of CRELD1 variants was characterized through an international collaboration utilizing next-generation DNA sequencing, gene knockdown, and protein overexpression in Xenopus tropicalis, and in vitro analysis of patient immune cells.

Results: Biallelic variants in CRELD1 were found in 18 participants from 14 families.

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Objective: To accurately categorize the phenotypes of individuals with collagen VI-related dystrophies (COL6-RDs) during the first years of life to predict long-term motor function and pulmonary function, to provide phenotype-specific anticipatory care, and to improve clinical trial readiness.

Methods: This retrospective, multicenter, international study analyzed the relationship of long-term motor and pulmonary function with the initial maximal motor ability achieved in individuals with COL6-RD.

Results: We studied 119 patients with COL6-RD from Spain (n = 54) and the United States (n = 65).

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Background: Only a few small studies have previously reported episodes of hypoglycemia in children with neuromuscular diseases; however, there has been no broader investigation into the occurrence of hypoglycemia in children with congenital muscle disease (CMD).

Methods: Pediatric patients enrolled in the CMD International Registry (CMDIR) with a history of hypoglycemia were included in this retrospective review. Hypoglycemic episodes and associated clinical and biochemical characteristics were characterized.

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Objective: To identify the rate of change of clinical outcome measures in children with 2 types of congenital muscular dystrophy (CMD), COL6-related dystrophies (COL6-RDs) and LAMA2-related dystrophies (LAMA2-RDs).

Methods: Over the course of 4 years, 47 individuals (23 with COL6-RD and 24 with LAMA2-RD) 4 to 22 years of age were evaluated. Assessments included the Motor Function Measure 32 (MFM32), myometry (knee flexors and extensors, elbow flexors and extensors), goniometry (knee and elbow extension), pulmonary function tests, and quality-of-life measures.

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Spinal muscular atrophy is one of the most common fatal autosomal recessive disorders. Children diagnosed with SMA Type 1 (SMAT1) demonstrate severe oral motor weakness and flaccid dysarthria progressing to complete anarthria. A review of literature illustrates that little has been described regarding augmentative and alternative communication (AAC) use among these children, although communication has a critical impact on quality of life and participation in daily activities.

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Objective: Comprehensive clinical characterization of congenital titinopathy to facilitate diagnosis and management of this important emerging disorder.

Methods: Using massively parallel sequencing we identified 30 patients from 27 families with 2 pathogenic nonsense, frameshift and/or splice site TTN mutations in trans. We then undertook a detailed analysis of the clinical, histopathological and imaging features of these patients.

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Collagen prolyl 4-hydroxylases (C-P4Hs) play a central role in the formation and stabilization of the triple helical domain of collagens. P4HA1 encodes the catalytic α(I) subunit of the main C-P4H isoenzyme (C-P4H-I). We now report human bi-allelic P4HA1 mutations in a family with a congenital-onset disorder of connective tissue, manifesting as early-onset joint hypermobility, joint contractures, muscle weakness and bone dysplasia as well as high myopia, with evidence of clinical improvement of motor function over time in the surviving patient.

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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.

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Introduction: Electrical impedance myography (EIM) is a noninvasive electrophysiological technique that characterizes muscle properties through bioimpedance. We compared EIM measurements to function, strength, and disease severity in a population with congenital muscular dystrophy (CMD).

Methods: Forty-one patients with CMD, either collagen 6 related disorders (COL6-RD; n = 21) or laminin α-2-related disorders (LAMA2-RD; n = 20), and 21 healthy pediatric controls underwent 2 yearly EIM exams.

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Congenital muscular dystrophy (CMD) comprises a rare group of genetic muscle diseases that present at birth or early during infancy. Two common subtypes of CMD are collagen VI-related muscular dystrophy (COL6-RD) and laminin alpha 2-related dystrophy (LAMA2-RD). Traditional outcome measures in CMD include gross motor and mobility assessments, yet significant motor declines underscore the need for valid upper extremity motor assessments as a clinical endpoint.

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Background: Progressive, restrictive, respiratory insufficiency is the major cause of morbidity and mortality in Congenital Muscular Dystrophy (CMD). Nocturnal hypoventilation precedes daytime alveolar hypoventilation, and if untreated, may lead to respiratory failure and cor pulmonale. CMD consensus care guidelines recommend screening for respiratory insufficiency by conventional and dynamic (sitting to supine) pulmonary function testing (PFT) and evaluating for sleep disordered breathing if there is more than 20% relative reduction from sitting to supine FVC(L) (ΔFVC).

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Hereditary spastic paraplegias are a clinically and genetically heterogeneous group of disorders characterized by lower extremity spasticity and weakness. Recently, the first de novo mutations in KIF1A were identified in patients with an early-onset severe form of complicated hereditary spastic paraplegia. We report two additional patients with novel de novo mutations in KIF1A, hereby expanding the genetic spectrum of KIF1A-related hereditary spastic paraplegia.

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Potential therapies are currently under development for two congenital muscular dystrophy (CMD) subtypes: collagen VI-related muscular dystrophy (COL6-RD) and laminin alpha 2-related dystrophy (LAMA2-RD). However, appropriate clinical outcome measures to be used in clinical trials have not been validated in CMDs. We conducted a two-year pilot study to evaluate feasibility, reliability, and validity of various outcome measures, particularly the Motor Function Measure 32, in 33 subjects with COL6-RD and LAMA2-RD.

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Collagen 6-related dystrophies and myopathies (COL6-RD) are a group of disorders that form a wide phenotypic spectrum, ranging from severe Ullrich congenital muscular dystrophy, intermediate phenotypes, to the milder Bethlem myopathy. Both inter- and intrafamilial variable expressivity are commonly observed. We present clinical, immunohistochemical, and genetic data on four COL6-RD families with marked intergenerational phenotypic heterogeneity.

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Objective: To develop and validate an English version of the Neuromuscular (NM)-Score, a classification for patients with NM diseases in each of the 3 motor function domains: D1, standing and transfers; D2, axial and proximal motor function; and D3, distal motor function.

Design: Validation survey.

Setting: Patients seen at a medical research center between June and September 2013.

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Duchenne muscular dystrophy (DMD) is caused by mutations in Dystrophin and affects 1 in 3600-6000 males. It is characterized by progressive weakness leading to loss of ambulation, respiratory insufficiency, cardiomyopathy, and scoliosis. We describe the unusual phenotype of 3 patients with skeletal dysplasias in whom an additional diagnosis of DMD was later established.

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Two mutational mechanisms are known to underlie Ullrich congenital muscular dystrophy (UCMD): heterozygous dominant negatively-acting mutations and recessively-acting loss-of-function mutations. We describe large genomic deletions on chromosome 21q22.3 as a novel type of mutation underlying recessively inherited UCMD in 2 families.

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