T2 Hyperintensities in Gracile Tracts of Cervical Spinal Cord in Giant Axonal Neuropathy (GAN).

Introduction/aims: Giant axonal neuropathy (GAN) is a hereditary neurodegenerative disease due to the absence or loss of function of the gigaxonin gene. Pathologic findings in GAN are those of "dying-back" axonal degeneration, in which the distal axon degenerates but the more proximal axon and neuronal cell body remain intact. Aims of this study were to (1) document imaging abnormalities that may occur in the spinal cords of GAN patients; and (2) assess histologically the spinal cords of GAN rodent models.

High-Density Lipoprotein-Associated Cholesterol Abnormalities in a Clinical Outcomes Study of Dysferlin-Deficient Limb-Girdle Muscular Dystrophy Type R2.

Background: Limb-girdle muscular dystrophy (MD) type R2 (LGMDR2, formerly LGMD2B) is an autosomal recessive form of MD caused by variants in the dysferlin gene, DYSF. It leads to slow proximal and distal muscle weakening that generally results in loss of ambulation around early adulthood but without the lethal cardiorespiratory dysfunction observed in the more severe Duchenne MD. How loss of dysferlin causes muscle fibre death is poorly understood, but recent evidence suggests a link between muscle wasting and loss of muscle cholesterol homeostasis with circulating lipoprotein abnormalities in many forms of MD.

High-dose flecainide for symptomatic relief in paramyotonia congenita/severe neonatal episodic laryngospasm due to SCN4A G1306E: a case report.

Background: Severe neonatal episodic laryngospasm has been previously reported in multiple patients with the heterozygous pathogenic variant G1306E in SCN4A. Treatment can be difficult due to side effects from therapies utilized conventionally for the management of myotonia and paramyotonia congenita.

Case Presentation: We report on two female siblings of Irish, Scandinavian, and German ethnicity aged 7 and 3 years with severe neonatal episodic laryngospasm and paramyotonia congenita due to a paternally inherited heterozygous pathogenic variant of the SCN4A gene and the use of high-dose flecainide therapy for symptomatic management.

Current clinical applications of AAV-mediated gene therapy.

Currently, there are an estimated 8,000 genetic disorders that cumulatively affect approximately 10% of the population. Even among the 5% of patients with genetic disease that have treatment options, these therapeutics rarely address the underlying cause of disease but rather focus on managing or modifying symptoms and typically require recurrent, lifelong therapy. A therapeutic approach to genetic disease that in vivo delivers a functional copy of the aberrant gene is an intuitive solution that has thus far taken 3 decades to reduce to clinical practice, predominantly using adeno-associated viral (AAV) vectors.

Phase 1 Open-Label Study of Omigapil in Patients With LAMA2- or COL6-Related Dystrophy.

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.

Intrathecal Gene Therapy for Giant Axonal Neuropathy.

Background: Giant axonal neuropathy is a rare, autosomal recessive, pediatric, polysymptomatic, neurodegenerative disorder caused by biallelic loss-of-function variants in , the gene encoding gigaxonin.

Methods: We conducted an intrathecal dose-escalation study of scAAV9/JeT-GAN (a self-complementary adeno-associated virus-based gene therapy containing the transgene) in children with giant axonal neuropathy. Safety was the primary end point.

PIEZO2-dependent rapid pain system in humans and mice.

The PIEZO2 ion channel is critical for transducing light touch into neural signals but is not considered necessary for transducing acute pain in humans. Here, we discovered an exception - a form of mechanical pain evoked by hair pulling. Based on observations in a rare group of individuals with PIEZO2 deficiency syndrome, we demonstrated that hair-pull pain is dependent on PIEZO2 transduction.

Intermediate filament dysregulation in astrocytes in the human disease model of mutation in giant axonal neuropathy (GAN).

Giant Axonal Neuropathy (GAN) is a pediatric neurodegenerative disease caused by mutations. encodes gigaxonin, which regulates intermediate filament (IF) turnover. Previous neuropathological studies and examination of postmortem brain tissue in the current study revealed involvement of astrocytes in GAN.

Surgical Management of Iris Bombe in Muscle-Eye-Brain Disease.

A 2-year-old girl with severe muscular dystrophy presented with unilateral eye pain and corneal clouding. She was found to have absent red reflex, hypotonia, cerebral hypoplasia, and iris bombe on ultrasound biomicroscopy, a feature not previously reported in this syndrome. She responded favorably to surgical management.

Neonatal Botulism: A Case Series Suggesting Varied Presentations.

Infantile botulism is an uncommon diagnosis and rarer still in the neonatal period. We describe three cases of neonatal-onset botulism that presented with symptoms typically (hypotonia, constipation, facial diplegia) or atypically seen in older infants (encephalopathy, seizures, and hypothermia). Our series shows a wider spectrum of clinical presentations in patients with neonatal-onset botulism.

Bi-allelic variants in HMGCR cause an autosomal-recessive progressive limb-girdle muscular dystrophy.

Statins are a mainstay intervention for cardiovascular disease prevention, yet their use can cause rare severe myopathy. HMG-CoA reductase, an essential enzyme in the mevalonate pathway, is the target of statins. We identified nine individuals from five unrelated families with unexplained limb-girdle like muscular dystrophy and bi-allelic variants in HMGCR via clinical and research exome sequencing.

Intermediate filament dysregulation and astrocytopathy in the human disease model of mutation in giant axonal neuropathy (GAN).

Giant Axonal Neuropathy (GAN) is a pediatric neurodegenerative disease caused by mutations. encodes gigaxonin, a regulator of intermediate filament (IF) protein turnover. Previous neuropathological studies and our own examination of postmortem GAN brain tissue in the current study revealed astrocyte involvement in GAN.

Expanding the muscle imaging spectrum in dysferlinopathy: description of an outlier population from the classical MRI pattern.

Dysferlinopathy is a muscle disease characterized by a variable clinical presentation and is caused by mutations in the DYSF gene. The Jain Clinical Outcome Study for Dysferlinopathy (COS) followed the largest cohort of patients (n=187) with genetically confirmed dysferlinopathy throughout a three-year natural history study, in which the patients underwent muscle function tests and muscle magnetic resonance imaging (MRI). We previously described the pattern of muscle pathology in this population and established a series of imaging criteria for diagnosis.

Myostatin and follistatin as monitoring and prognostic biomarkers in dysferlinopathy.

Myostatin is a myokine which acts upon skeletal muscle to inhibit growth and regeneration. Myostatin is endogenously antagonised by follistatin. This study assessed serum myostatin and follistatin concentrations as monitoring or prognostic biomarkers in dysferlinopathy, an autosomal recessively inherited muscular dystrophy.

Water T2 could predict functional decline in patients with dysferlinopathy.

Background: Water T2 (T2 ) mapping is increasingly being used in muscular dystrophies to assess active muscle damage. It has been suggested as a surrogate outcome measure for clinical trials. Here, we investigated the prognostic utility of T2 to identify changes in muscle function over time in limb girdle muscular dystrophies.

Comparison of strength testing modalities in dysferlinopathy.

Introduction/aims: Dysferlinopathy demonstrates heterogeneity in muscle weakness between patients, which can progress at different rates over time. Changing muscle strength due to disease progression or from an investigational product is associated with changing functional ability. The purpose of this study was to compare three methods of strength testing used in the Clinical Outcome Study (COS) for dysferlinopathy to understand which method and which muscle groups were most sensitive to change over time.

Assessing the Relationship of Patient Reported Outcome Measures With Functional Status in Dysferlinopathy: A Rasch Analysis Approach.

Dysferlinopathy is a muscular dystrophy with a highly variable functional disease progression in which the relationship of function to some patient reported outcome measures (PROMs) has not been previously reported. This analysis aims to identify the suitability of PROMs and their association with motor performance.Two-hundred and four patients with dysferlinopathy were identified in the Jain Foundation's Clinical Outcome Study in Dysferlinopathy from 14 sites in 8 countries.

Cardiac and pulmonary findings in dysferlinopathy: A 3-year, longitudinal study.

Introduction/aims: There is debate about whether and to what extent either respiratory or cardiac dysfunction occurs in patients with dysferlinopathy. This study aimed to establish definitively whether dysfunction in either system is part of the dysferlinopathy phenotype.

Methods: As part of the Jain Foundation's International Clinical Outcome Study (COS) for dysferlinopathy, objective measures of respiratory and cardiac function were collected twice, with a 3-y interval between tests, in 188 genetically confirmed patients aged 11-86 y (53% female).

Anesthetic Management of Children and Adolescents With Giant Axonal Neuropathy: A Large Case Series.

Giant axonal neuropathy (GAN) is a rare autosomal recessive neurodegenerative disorder caused by mutations in the GAN gene, which encodes for gigaxonin, a protein involved in intermediate filament processing in neural cells and fibroblasts. We report on 14 GAN patients who underwent 77 anesthetics during the conduct of an intrathecal gene transfer clinical trial from April 2015 to August 2020. We observed only a few nonsignificant perianesthetic complications.

Ethical challenges for a new generation of early-phase pediatric gene therapy trials.

After decades of setbacks, gene therapy (GT) is experiencing major breakthroughs. Five GTs have received US regulatory approval since 2017, and over 900 others are currently in development. Many of these GTs target rare pediatric diseases that are severely life-limiting, given a lack of effective treatments.

Giant axonal neuropathy: cross-sectional analysis of a large natural history cohort.

Giant axonal neuropathy (GAN) is an ultra-rare autosomal recessive, progressive neurodegenerative disease with early childhood onset that presents as a prominent sensorimotor neuropathy and commonly progresses to affect both the PNS and CNS. The disease is caused by biallelic mutations in the GAN gene located on 16q23.2, leading to loss of functional gigaxonin, a substrate specific ubiquitin ligase adapter protein necessary for the regulation of intermediate filament turnover.

Clinical and Molecular Spectrum Associated with COL6A3 c.7447A>G p.(Lys2483Glu) Variant: Elucidating its Role in Collagen VI-related Myopathies.

Background: Dominant and recessive autosomal pathogenic variants in the three major genes (COL6A1-A2-A3) encoding the extracellular matrix protein collagen VI underlie a group of myopathies ranging from early-onset severe conditions (Ullrich congenital muscular dystrophy) to milder forms maintaining independent ambulation (Bethlem myopathy). Diagnosis is based on the combination of clinical presentation, muscle MRI, muscle biopsy, analysis of collagen VI secretion, and COL6A1-A2-A3 genetic analysis, the interpretation of which can be challenging.

Objective: To refine the phenotypical spectrum associated with the frequent COL6A3 missense variant c.