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Summary: Background: With increasing recognition of the value of incorporating prognostic markers into amyotrophic lateral sclerosis (ALS) trial design and analysis plans, there is a pressing need to understand which among the prevailing clinical and biochemical markers have real value, and how they can be optimally used. Methods: A subset of patients with ALS recruited through the multi-center Phenotype-Genotype-Biomarker study (clinicaltrials.gov: NCT02327845) was identified as “trial-like” based on meeting common trial eligibility criteria. Clinical phenotyping was performed by evaluators trained in relevant assessments. Serum neurofilament light (NfL) and phosphorylated neurofilament heavy (pNfH), urinary p75ECD, plasma microRNA-181, and an array of biochemical and clinical measures were evaluated for their prognostic value. Associations with functional progression were estimated by random-slopes mixed models of ALS functional rating scale-revised (ALSFRS-R) score. Associations with survival were estimated by log-rank test and Cox proportional hazards regression. Potential sample size savings from adjusting for given biomarkers in a hypothetical trial were estimated. Findings: Baseline serum NfL is a powerful prognostic biomarker, predicting survival and ALSFRS-R rate of decline. Serum NfL 100 pg/mL correspond to future ALSFRS-R slopes of ∼0.5 and ∼1.5 points/month, respectively. Serum NfL also adds value to the best available clinical predictors, encapsulated by the European Network to Cure ALS (ENCALS) predictor score. In models of functional decline, the addition of NfL yields ∼25% sample size saving above those achieved by inclusion of either clinical predictors or ENCALS score alone. The prognostic value of serum pNfH, urinary p75ECD, and plasma miR-181ab is more limited. Interpretation: Among the multitude of biomarkers considered, only blood NfL adds value to the ENCALS prediction model and should be incorporated into analysis plans for all ongoing and future ALS trials. Defined thresholds of NfL might also be used in trial design, for enrichment or stratified randomisation, to improve trial efficiency. Funding: NIH (U01-NS107027, U54-NS092091). ALSA (16-TACL-242).

Abstract Objectives To assess the safety, tolerability, and key pharmacodynamic effects of subcutaneous batoclimab, a fully human anti‐neonatal Fc receptor monoclonal antibody, in patients with generalized myasthenia gravis and anti‐acetylcholine receptor antibodies. Methods A Phase 2a, proof‐of‐concept, randomized, double‐blind, placebo‐controlled trial is described. Eligible patients were randomized (1:1:1) to receive once‐weekly subcutaneous injections of batoclimab 340 mg, batoclimab 680 mg, or matching placebo for 6 weeks. Subsequently, all patients could enter an open‐label extension study where they received batoclimab 340 mg once every 2 weeks for 6 weeks. Primary endpoints were safety, tolerability, and change from baseline in total immunoglobulin G, immunoglobulin G subclasses, and anti‐acetylcholine receptor antibodies at 6 weeks post‐baseline. Secondary endpoints included changes from baseline to 6 weeks post‐baseline for Myasthenia Gravis Activities of Daily Living, Quantitative Myasthenia Gravis, Myasthenia Gravis Composite, and revised 15‐item Myasthenia Gravis Quality of Life scores. Results Seventeen patients were randomized to batoclimab 680 mg (n = 6), batoclimab 340 mg (n = 5), or placebo (n = 6). Batoclimab was associated with significantly greater reductions in total immunoglobulin G and anti‐acetylcholine receptor antibodies from baseline to 6 weeks post‐baseline than placebo. Reductions in immunoglobulin G subclasses were generally consistent with total immunoglobulin G. While clinical measures showed directionally favorable improvements over time, the study was not powered to draw conclusions about therapeutic efficacy. No safety issues were identified. Interpretation The safety profile, pharmacodynamics, and preliminary clinical benefits observed in this study support further investigation of subcutaneous batoclimab injections as a potential patient‐administered therapy for seropositive generalized myasthenia gravis.

Introduction Batoclimab, a fully human monoclonal antibody that inhibits the neonatal fragment crystallisable receptor, has shown promising phase 2 clinical trial results in patients with generalised myasthenia gravis (gMG).Methods and analysis In this phase 3, randomised, quadruple-blind, placebo-controlled study, adults with gMG will be randomised 1:1:1 to induction therapy with batoclimab 680 mg, batoclimab 340 mg, or placebo, administered once weekly (QW) for 12 weeks as a subcutaneous injection. The primary endpoint is the change from baseline to week 12 on the Myasthenia Gravis Activities of Daily Living (MG-ADL) score. Batoclimab-treated patients achieving a ≥2-point improvement from baseline on MG-ADL at week 10 or week 12 will be re-randomised to maintenance treatment with batoclimab 340 mg QW, batoclimab 340 mg every other week (Q2W), or placebo for 12 weeks; batoclimab-treated patients with a

Abstract A summit held March 2023 in Scottsdale, Arizona (USA) focused on the intronic hexanucleotide expansion in the C9ORF72 gene and its relevance in frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS; C9ORF72-FTD/ALS). The goal of this summit was to connect basic scientists, clinical researchers, drug developers, and individuals affected by C9ORF72-FTD/ALS to evaluate how collaborative efforts across the FTD-ALS disease spectrum might break down existing disease silos. Presentations and discussions covered recent discoveries in C9ORF72-FTD/ALS disease mechanisms, availability of disease biomarkers and recent advances in therapeutic development, and clinical trial design for prevention and treatment for individuals affected by C9ORF72-FTD/ALS and asymptomatic pathological expansion carriers. The C9ORF72-associated hexanucleotide repeat expansion is an important locus for both ALS and FTD. C9ORF72-FTD/ALS may be characterized by loss of function of the C9ORF72 protein and toxic gain of functions caused by both dipeptide repeat (DPR) proteins and hexanucleotide repeat RNA. C9ORF72-FTD/ALS therapeutic strategies discussed at the summit included the use of antisense oligonucleotides, adeno-associated virus (AAV)-mediated gene silencing and gene delivery, and engineered small molecules targeting RNA structures associated with the C9ORF72 expansion. Neurofilament light chain, DPR proteins, and transactive response (TAR) DNA-binding protein 43 (TDP-43)–associated molecular changes were presented as biomarker candidates. Similarly, brain imaging modalities (i.e., magnetic resonance imaging [MRI] and positron emission tomography [PET]) measuring structural, functional, and metabolic changes were discussed as important tools to monitor individuals affected with C9ORF72-FTD/ALS, at both pre-symptomatic and symptomatic disease stages. Finally, summit attendees evaluated current clinical trial designs available for FTD or ALS patients and concluded that therapeutics relevant to FTD/ALS patients, such as those specifically targeting C9ORF72, may need to be tested with composite endpoints covering clinical symptoms of both FTD and ALS. The latter will require novel clinical trial designs to be inclusive of all patient subgroups spanning the FTD/ALS spectrum.

Nitrous oxide-induced myelopathy is a relatively well-known clinical entity. Less well-known, however, is the rare inverse Lhermitte phenomenon, where neck flexion elicits an ascending, rather than descending, electric shock-like sensation. This is a characteristic symptom and sign that may occur in nitrous oxide toxicity. In this article, we present the case of a patient who was admitted to our hospital with suspected Guillain-Barré syndrome due to her ascending numbness and unsteady gait. We describe her examination and laboratory features leading to the correct diagnosis, along with a historical review of the various subtypes of the Lhermitte phenomenon and the pathophysiology of nitrous oxide-induced myelopathy.

BackgroundWith more than 103 million cases and 1.1 million deaths, the COVID-19 pandemic has had devastating consequences for the health system and the well-being of the entire US population. The Rare Diseases Clinical Research Network funded by the National Institutes of Health was strategically positioned to study the impact of the pandemic on the large, vulnerable population of people living with rare diseases (RDs). ObjectiveThis study was designed to describe the characteristics of COVID-19 in the RD population, determine whether patient subgroups experienced increased occurrence or severity of infection and whether the pandemic changed RD symptoms and treatment, and understand the broader impact on respondents and their families. MethodsUS residents who had an RD and were 9 symptoms vs none: OR 82.5, 95% CI 29-234 and 5-9: OR 44.8, 95% CI 18.7-107). Median symptom duration was 16 (IQR 9-30) days. Hospitalization (7/71, 10%) and ventilator support (4/71, 6%) were uncommon. Respondents who acquired COVID-19 reported increased occurrence and severity of RD symptoms and use or dosage of select medications; those who did not acquire COVID-19 reported decreased occurrence and severity of RD symptoms and use of medications; those who did not know had an intermediate pattern. The pandemic made it difficult to access care, receive treatment, get hospitalized, and caused mood changes for respondents and their families. ConclusionsSelf-reported COVID-19 was more frequent than expected and was associated with increased prevalence and severity of RD symptoms and greater use of medications. The pandemic negatively affected access to care and caused mood changes in the respondents and family members. Continued surveillance is necessary.

Objective: The corticospinal tract (CST) reveals progressive microstructural alterations in ALS measurable by DTI. The aim of this study was to evaluate fractional anisotropy (FA) along the CST as a longitudinal marker of disease progression in ALS. Methods: The study cohort consisted of 114 patients with ALS and 110 healthy controls from the second prospective, longitudinal, multicentre study of the Canadian ALS Neuroimaging Consortium (CALSNIC-2). DTI and clinical data from a harmonized protocol across 7 centres were collected. Thirty-nine ALS patients and 61 controls completed baseline and two follow-up visits and were included for longitudinal analyses. Whole brain-based spatial statistics and hypothesis-guided tract-of-interest analyses were performed for cross-sectional and longitudinal analyses. Results: FA was reduced at baseline and longitudinally in the CST, mid-corpus callosum (CC), frontal lobe, and other ALS-related tracts, with alterations most evident in the CST and mid-CC. CST and pontine FA correlated with functional impairment (ALSFRS-R), upper motor neuron function, and clinical disease progression rate. Reduction in FA was largely located in the upper CST; however, the longitudinal decline was greatest in the lower CST. Effect sizes were dependent on region, resulting in study group sizes between 17 and 31 per group over a 9-month interval. Cross-sectional effect sizes were maximal in the upper CST; whereas, longitudinal effect sizes were maximal in mid-callosal tracts. Conclusions: Progressive microstructural alterations in ALS are most prominent in the CST and CC. DTI can provide a biomarker of cerebral degeneration in ALS, with longitudinal changes in white matter demonstrable over a reasonable observation period, with a feasible number of participants, and within a multicentre framework.

A hexanucleotide repeat expansion in C9ORF72 is the most common genetic cause of ALS and FTD. Here, the authors demonstrate CRISPR/Cas9 excision of the expansion results in a rescue of disease mechanisms in vivo and in vitro.

IntroductionLimited diagnostics are available for inherited neuromuscular diseases (NMD) in South Africa and (excluding muscle disease) are mainly aimed at the most frequent genes underlying genetic neuropathy (GN) and spastic ataxias in Europeans. In this study, we used next-generation sequencing to screen 61 probands with GN, hereditary spastic paraplegia (HSP), and spastic ataxias for a genetic diagnosis.MethodsAfter identifying four GN probands with PMP22 duplication and one spastic ataxia proband with SCA1, the remaining probands underwent whole exome (n = 26) or genome sequencing (n = 30). The curation of coding/splice region variants using gene panels was guided by allele frequencies from internal African-ancestry control genomes (n = 537) and the Clinical Genome Resource's Sequence Variant Interpretation guidelines.ResultsOf 32 GN probands, 50% had African-genetic ancestry, and 44% were solved: PMP22 (n = 4); MFN2 (n = 3); one each of MORC2, ATP1A1, ADPRHL2, GJB1, GAN, MPZ, and ATM. Of 29 HSP probands (six with predominant ataxia), 66% had African-genetic ancestry, and 48% were solved: SPG11 (n = 3); KIF1A (n = 2); and one each of SPAST, ATL1, SPG7, PCYT2, PSEN1, ATXN1, ALDH18A1, CYP7B1, and RFT1. Structural variants in SPAST, SPG11, SPG7, MFN2, MPZ, KIF5A, and GJB1 were excluded by computational prediction and manual visualisation.DiscussionIn this preliminary cohort screening panel of disease genes using WES/WGS data, we solved ~50% of cases, which is similar to diagnostic yields reported for global cohorts. However, the mutational profile among South Africans with GN and HSP differs substantially from that in the Global North.

Summary: Background: As novel therapeutic interventions are being developed and tested in the amyotrophic lateral sclerosis (ALS) population, there is a need to better understand the symptoms and issues that have the greatest impact on the lives of individuals with ALS. We aimed to determine the frequency and relative importance of symptoms experienced by adults in a national ALS sample and to identify factors that are associated with the greatest disease burden in this population. Methods: We conducted 15 qualitative interviews of individuals with varied ALS phenotypes and analyzed 732 quotes regarding the symptomatic disease burden of ALS between August 2018 and March 2019. We subsequently conducted a national, cross-sectional study of 497 participants with ALS and ALS variants through the Centers for Disease Control and Prevention's (CDC) National ALS Registry between July 2019 and December 2019. Participants reported on the prevalence and relative importance of 189 symptomatic questions representing 17 symptomatic themes that were previously identified through qualitative interviews. Analysis was performed to determine how age, sex, education, employment, time since onset of symptoms, location of symptom onset, feeding tube status, breathing status and speech status relate to symptom and symptomatic theme prevalence. Findings: Symptomatic themes with the highest prevalence in our sample were an inability to do activities (93.8%), fatigue (92.6%), problems with hands or fingers (87.7%), limitations with mobility or walking (86.7%), and a decreased performance in social situations (85.7%). Participants identified inability to do activities and limitations with mobility or walking as having the greatest overall effect on their lives. Interpretation: Individuals with ALS experience a variety of symptoms that affect their lives. The prevalence and importance of these symptoms differ among the ALS population. The most prevalent and important symptoms offer potential targets for improvements in future therapeutic interventions. Funding: Research funding was provided by ALS Association.

Abstract Objective To appraise the utility as biomarkers of blood antibodies and immune complexes to neurofilaments and dipeptide repeat proteins, the products of translation of the most common genetic mutation in amyotrophic lateral sclerosis (ALS). Methods Antibodies and immune complexes against neurofilament light, medium, heavy chains as well as poly‐(GP)‐(GR) dipeptide repeats were measured in blood samples from the ALS Biomarkers (n = 107) and the phenotype–genotype biomarker (n = 129) studies and in 140 healthy controls. Target analyte levels were studied longitudinally in 37 ALS cases. Participants were stratified according to the rate of disease progression estimated before and after baseline and C9orf72 genetic status. Survival and longitudinal analyses were undertaken with reference to matched neurofilament protein expression. Results Compared to healthy controls, total neurofilament proteins and antibodies, neurofilament light immune complexes (p

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized primarily by progressive loss of motor neurons. Although ALS occurs worldwide and the frequency and spectrum of identifiable genetic causes of disease varies across populations, very few studies have included African subjects. In addition to a hexanucleotide repeat expansion (RE) in C9orf72, the most common genetic cause of ALS in Europeans, REs in ATXN2, NIPA1 and ATXN1 have shown variable associations with ALS in Europeans. Intermediate range expansions in some of these genes (e.g. ATXN2) have been reported as potential risk factors, or phenotypic modifiers, of ALS. Pathogenic expansions in NOP56 cause spinocerebellar ataxia-36, which can present with prominent motor neuron degeneration. Here we compare REs in these genes in a cohort of Africans with ALS and population controls using whole genome sequencing data. Targeting genotyping of short tandem repeats at known loci within ATXN2, NIPA1, ATXN1 and NOP56 was performed using ExpansionHunter software in 105 Southern African (SA) patients with ALS. African population controls were from an in-house SA population control database (n = 25), the SA Human Genome Program (n = 24), the Simons Genome Diversity Project (n = 39) and the Illumina Polaris Diversity Cohort (IPDC) dataset (n = 50). We found intermediate RE alleles in ATXN2 (27–33 repeats) and ATXN1 (33–35 repeats), and NIPA1 long alleles (≥8 repeats) were rare in Africans, and not associated with ALS (p > 0.17). NOP56 showed no expanded alleles in either ALS or controls. We also compared the differences in allele distributions between the African and n = 50 European controls (from the IPDC). There was a statistical significant difference in the distribution of the REs in the ATXN1 between African and European controls (Chi-test p 8) in Europeans vs. Africans (Fisher’s p = 0.016). The distribution of RE alleles in ATXN2 and NOP56 were similar amongst African and European controls. In conclusion, repeat expansions in ATXN2, NIPA1 and ATXN1, which showed associations with ALS in Europeans, were not replicated in Southern Africans with ALS.

Abstract Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive muscle weakness. Skeletal muscle is a prime source for biomarker discovery since it is one of the earliest sites to manifest disease pathology. From a prior RNA sequencing project, we identified FGF23 as a potential muscle biomarker in ALS. Here, we validate this finding with a large collection of ALS muscle samples and found a 13-fold increase over normal controls. FGF23 was also increased in the SOD1G93A mouse, beginning at a very early stage and well before the onset of clinical symptoms. FGF23 levels progressively increased through end-stage in the mouse. Immunohistochemistry of ALS muscle showed prominent FGF23 immunoreactivity in the endomysial connective tissue and along the muscle membrane and was significantly higher around grouped atrophic fibers compared to non-atrophic fibers. ELISA of plasma samples from the SOD1G93A mouse showed an increase in FGF23 at end-stage whereas no increase was detected in a large cohort of ALS patients. In conclusion, FGF23 is a novel muscle biomarker in ALS and joins a molecular signature that emerges in very early preclinical stages. The early appearance of FGF23 and its progressive increase with disease progression offers a new direction for exploring the molecular basis and response to the underlying pathology of ALS.

Abstract Amyotrophic lateral sclerosis (ALS) is a multi‐system disease characterized primarily by progressive muscle weakness. Cognitive dysfunction is commonly observed in patients; however, factors influencing risk for cognitive dysfunction remain elusive. Using sparse canonical correlation analysis (sCCA), an unsupervised machine‐learning technique, we observed that single nucleotide polymorphisms collectively associate with baseline cognitive performance in a large ALS patient cohort (N = 327) from the multicenter Clinical Research in ALS and Related Disorders for Therapeutic Development (CReATe) Consortium. We demonstrate that a polygenic risk score derived using sCCA relates to longitudinal cognitive decline in the same cohort and also to in vivo cortical thinning in the orbital frontal cortex, anterior cingulate cortex, lateral temporal cortex, premotor cortex, and hippocampus (N = 90) as well as post‐mortem motor cortical neuronal loss (N = 87) in independent ALS cohorts from the University of Pennsylvania Integrated Neurodegenerative Disease Biobank. Our findings suggest that common genetic polymorphisms may exert a polygenic contribution to the risk of cortical disease vulnerability and cognitive dysfunction in ALS.

Abstract Objective To evaluate the CSF levels of chitinase proteins during the presymptomatic and early symptomatic phases of amyotrophic lateral sclerosis (ALS). Methods CSF samples were obtained from 16 controls, 55 individuals at‐risk for ALS (including 18 carrying a mutation in C9ORF72, 33 in SOD1), 12 ALS patients, and 7 phenoconverters (individuals diagnosed with ALS during follow‐up). At‐risk individuals and phenoconverters were enrolled through the Pre‐fALS study, which includes individuals carrying an ALS‐associated gene mutation without disease manifestations at initial assessment. Longitudinal CSF collections, where possible, took place every 3‐12 months for ALS patients and every 1‐2 years for others. CSF levels of chitotriosidase 1 (CHIT1), chitinase‐3‐like protein 1 (CHI3L1, YKL‐40) and chitinase‐3‐like protein 2 (CHI3L2, YKL‐39) were measured by ELISA, along with CHIT1 activity. Longitudinal changes in at‐risk individuals and phenoconverters were fitted to linear mixed effects models. Results Slowly rising levels of CHIT1 were observed over time in the at‐risk individuals (slope 0.059 log10[CHIT1] per year, P

Abstract Background The C9ORF72 hexanucleotide repeat expansion is the most common known genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), two fatal age-related neurodegenerative diseases. The C9ORF72 expansion encodes five dipeptide repeat proteins (DPRs) that are produced through a non-canonical translation mechanism. Among the DPRs, proline-arginine (PR), glycine-arginine (GR), and glycine-alanine (GA) are the most neurotoxic and increase the frequency of DNA double strand breaks (DSBs). While the accumulation of these genotoxic lesions is increasingly recognized as a feature of disease, the mechanism(s) of DPR-mediated DNA damage are ill-defined and the effect of DPRs on the efficiency of each DNA DSB repair pathways has not been previously evaluated. Methods and results Using DNA DSB repair assays, we evaluated the efficiency of specific repair pathways, and found that PR, GR and GA decrease the efficiency of non-homologous end joining (NHEJ), single strand annealing (SSA), and microhomology-mediated end joining (MMEJ), but not homologous recombination (HR). We found that PR inhibits DNA DSB repair, in part, by binding to the nucleolar protein nucleophosmin (NPM1). Depletion of NPM1 inhibited NHEJ and SSA, suggesting that NPM1 loss-of-function in PR expressing cells leads to impediments of both non-homologous and homology-directed DNA DSB repair pathways. By deleting NPM1 sub-cellular localization signals, we found that PR binds NPM1 regardless of the cellular compartment to which NPM1 was directed. Deletion of the NPM1 acidic loop motif, known to engage other arginine-rich proteins, abrogated PR and NPM1 binding. Using confocal and super-resolution immunofluorescence microscopy, we found that levels of RAD52, a component of the SSA repair machinery, were significantly increased iPSC neurons relative to isogenic controls in which the C9ORF72 expansion had been deleted using CRISPR/Cas9 genome editing. Western analysis of post-mortem brain tissues confirmed that RAD52 immunoreactivity is significantly increased in C9ALS/FTD samples as compared to controls. Conclusions Collectively, we characterized the inhibitory effects of DPRs on key DNA DSB repair pathways, identified NPM1 as a facilitator of DNA repair that is inhibited by PR, and revealed deficits in homology-directed DNA DSB repair pathways as a novel feature of C9ORF72-related disease.

Amyotrophic lateral sclerosis (ALS) is a multisystem neurodegenerative disorder characterized by progressive degeneration of upper motor neurons and lower motor neurons, and frontotemporal regions resulting in impaired bulbar, limb, and cognitive function. Magnetic resonance imaging studies have reported cortical and subcortical brain involvement in the pathophysiology of ALS. The present study investigates the functional integrity of resting-state networks (RSNs) and their importance in ALS. Intra- and inter-network resting-state functional connectivity (Rs-FC) was examined using an independent component analysis approach in a large multi-center cohort. A total of 235 subjects (120 ALS patients; 115 healthy controls (HC) were recruited across North America through the Canadian ALS Neuroimaging Consortium (CALSNIC). Intra-network and inter-network Rs-FC was evaluated by the FSL-MELODIC and FSLNets software packages. As compared to HC, ALS patients displayed higher intra-network Rs-FC in the sensorimotor, default mode, right and left fronto-parietal, and orbitofrontal RSNs, and in previously undescribed networks including auditory, dorsal attention, basal ganglia, medial temporal, ventral streams, and cerebellum which negatively correlated with disease severity. Furthermore, ALS patients displayed higher inter-network Rs-FC between the orbitofrontal and basal ganglia RSNs which negatively correlated with cognitive impairment. In summary, in ALS there is an increase in intra- and inter-network functional connectivity of RSNs underpinning both motor and cognitive impairment. Moreover, the large multi-center CALSNIC dataset permitted the exploration of RSNs in unprecedented detail, revealing previously undescribed network involvement in ALS.

AbstractNumerous reports have suggested that infectious agents could play a role in neurodegenerative diseases, but specific etiological agents have not been convincingly demonstrated. To search for candidate agents in an unbiased fashion, we have developed a bioinformatic pipeline that identifies microbial sequences in mammalian RNA-seq data, including sequences with no significant nucleotide similarity hits in GenBank. Effectiveness of the pipeline was tested using publicly available RNA-seq data and in a reconstruction experiment using synthetic data. We then applied this pipeline to a novel RNA-seq dataset generated from a cohort of 120 samples from amyotrophic lateral sclerosis patients and controls, and identified sequences corresponding to known bacteria and viruses, as well as novel virus-like sequences. The presence of these novel virus-like sequences, which were identified in subsets of both patients and controls, were confirmed by quantitative RT-PCR. We believe this pipeline will be a useful tool for the identification of potential etiological agents in the many RNA-seq datasets currently being generated.

Objectives To approximate the rate of familial myasthenia gravis and the coexistence of other autoimmune disorders in the patients and their families.Design Retrospective cohort study.Setting Clinics across North America.Participants The study included 1032 patients diagnosed with acetylcholine receptor antibody (AChR)-positive myasthenia gravis.Methods Phenotype information of 1032 patients diagnosed with AChR-positive myasthenia gravis was obtained from clinics at 14 centres across North America between January 2010 and January 2011. A critical review of the epidemiological literature on the familial rate of myasthenia gravis was also performed.Results Among 1032 patients, 58 (5.6%) reported a family history of myasthenia gravis. A history of autoimmune diseases was present in 26.6% of patients and in 28.4% of their family members.Discussion The familial rate of myasthenia gravis was higher than would be expected for a sporadic disease. Furthermore, a high proportion of patients had a personal or family history of autoimmune disease. Taken together, these findings suggest a genetic contribution to the pathogenesis of myasthenia gravis.

Amyotrophic lateral sclerosis (ALS) is a progressive and fatal neurodegenerative disease with available treatments only marginally slowing progression or improving survival. A hexanucleotide repeat expansion mutation in the C9ORF72 gene is the most commonly known genetic cause of both sporadic and familial cases of ALS and frontotemporal dementia (FTD). The C9ORF72 expansion mutation produces five dipeptide repeat proteins (DPRs), and while the mechanistic determinants of DPR-mediated neurotoxicity remain incompletely understood, evidence suggests that disruption of nucleocytoplasmic transport and increased DNA damage contributes to pathology. Therefore, characterizing these disturbances and determining the relative contribution of different DPRs is needed to facilitate the development of novel therapeutics for C9ALS/FTD. To this end, we generated a series of nucleocytoplasmic transport “biosensors”, composed of the green fluorescent protein (GFP), fused to different classes of nuclear localization signals (NLSs) and nuclear export signals (NESs). Using these biosensors in conjunction with automated microscopy, we investigated the role of the three most neurotoxic DPRs (PR, GR, and GA) on seven nuclear import and two export pathways. In addition to other DPRs, we found that PR had pronounced inhibitory effects on the classical nuclear export pathway and several nuclear import pathways. To identify compounds capable of counteracting the effects of PR on nucleocytoplasmic transport, we developed a nucleocytoplasmic transport assay and screened several commercially available compound libraries, totaling 2714 compounds. In addition to restoring nucleocytoplasmic transport efficiencies, hits from the screen also counteract the cytotoxic effects of PR. Selected hits were subsequently tested for their ability to rescue another C9ALS/FTD phenotype—persistent DNA double strand breakage. Overall, we found that DPRs disrupt multiple nucleocytoplasmic transport pathways and we identified small molecules that counteract these effects—resulting in increased viability of PR-expressing cells and decreased DNA damage markers in patient-derived motor neurons. Several HDAC inhibitors were validated as hits, supporting previous studies that show that HDAC inhibitors confer therapeutic effects in neurodegenerative models.

Abstract Background Amyotrophic Lateral Sclerosis (ALS) is a fatal and progressive neurodegenerative disorder with identified genetic causes representing a significant minority of all cases. A GGGGCC hexanucleotide repeat expansion (HRE) mutation within the C9ORF72 gene has recently been identified as the most frequent known cause of ALS. The expansion leads to partial heterochromatinization of the locus, yet mutant RNAs and dipeptide repeat proteins (DPRs) are still produced in sufficient quantities to confer neurotoxicity. The levels of these toxic HRE products positively correlate with cellular toxicity and phenotypic severity across multiple disease models. Moreover, the degree of epigenetic repression inversely correlates with some facets of clinical presentation in C9-ALS patients. Recently, bacterial artificial chromosomes (BAC) have been used to generate transgenic mice that harbor the HRE mutation, complementing other relevant model systems such as patient-derived induced pluripotent stem cells (iPSCs). While epigenetic features of the HRE have been investigated in various model systems and post-mortem tissues, epigenetic dysregulation at the expanded locus in C9-BAC mice remains unexplored. Methods and Results Here, we sought to determine whether clinically relevant epigenetic perturbations caused by the HRE are mirrored in a C9-BAC mouse model. We used complementary DNA methylation assessment and immunoprecipitation methods to demonstrate that epigenetic aberrations caused by the HRE, such as DNA and histone methylation, are recapitulated in the C9-BAC mice. Strikingly, we found that cytosine hypermethylation within the promoter region of the human transgene occurred in a subset of C9-BAC mice similar to what is observed in patient populations. Moreover, we show that partial heterochromatinization of the C9 HRE occurs during the first weeks of the mouse lifespan, indicating age-dependent epigenetic repression. Using iPSC neurons, we found that preventing R-loop formation did not impede heterochromatinization of the HRE. Conclusions Taken together, these observations provide further insight into mechanism and developmental time-course of epigenetic perturbations conferred by the C9ORF72 HRE. Finally, we suggest that epigenetic repression of the C9ORF72 HRE and nearby gene promoter could impede or delay motor neuron degeneration in C9-BAC mouse models of ALS/FTD.

Objectives: Disease-modifying therapies for amyotrophic lateral sclerosis (ALS) are still not satisfactory. The Rho kinase (ROCK) inhibitor fasudil has demonstrated beneficial effects in cell culture and animal models of ALS. For many years, fasudil has been approved in Japan for the treatment of vasospasm in patients with subarachnoid hemorrhage with a favorable safety profile. Here we describe a clinical trial protocol to repurpose fasudil as a disease-modifying therapy for ALS patients.Methods: ROCK-ALS is a multicenter, double-blind, randomized, placebo-controlled phase IIa trial of fasudil in ALS patients (EudraCT: 2017-003676-31, NCT: 03792490). Safety and tolerability are the primary endpoints. Efficacy is a secondary endpoint and will be assessed by the change in ALSFRS-R, ALSAQ-5, slow vital capacity (SVC), ECAS, and the motor unit number index (MUNIX), as well as survival. Efficacy measures will be assessed before (baseline) and immediately after the infusion therapy as well as on days 90 and 180. Patients will receive a daily dose of either 30 or 60 mg fasudil, or placebo in two intravenous applications for a total of 20 days. Regular assessments of safety will be performed throughout the treatment period, and in the follow-up period until day 180. Additionally, we will collect biological fluids to assess target engagement and evaluate potential biomarkers for disease progression. A total of 120 patients with probable or definite ALS (revised El Escorial criteria) and within 6–18 months of the onset of weakness shall be included in 16 centers in Germany, Switzerland and France.Results and conclusions: The ROCK-ALS trial is a phase IIa trial to evaluate the ROCK-inhibitor fasudil in early-stage ALS-patients that started patient recruitment in 2019.

Splined joints are commonly used to transmit rotary motion from a shaft to machine elements such as gears. While computationally efficient spline load distribution models have recently been proposed, there is no validated load distribution model of a splined joint due to lack of high-fidelity experimental data. Accordingly, this study aims to establish an extensive experimental database on load distributions of splined joints subject to both spur and helical gear loading conditions. A quasi-static, spline-specific test setup is developed and instrumented. A test matrix covering various loading conditions is executed in order to form a spline load distribution database. The experimental data illustrates the cyclic nature of loads and resultant stresses on spline teeth caused by rotation of the spline teeth in relation to the gear mesh that loads the splined joint. A nonlinear relationship between torque applied and resultant stress is revealed, as well as the relationship between the location of maximum stress along the face width and the amount of lead crown modification applied. Lastly, simulation results from the model of Hong et al. (2014b) are compared to the experimental data under spur and helical gear loading conditions to assess the premise of such models.

Therapeutic success in the superoxide dismutase (SOD1) mouse model of amyotrophic lateral sclerosis (ALS) has not translated into effective therapy for human ALS, calling into question the utility of such preclinical data for identifying therapeutic agents that are worthy of further study in humans. This random effects meta-analysis of treatment trials in the superoxide dismutase (SOD1) mouse was undertaken in order to explore possible reasons for this failure of translational research and to identify potential pharmacological interventions that might be used in either a preventative or therapeutic trial in familial ALS. Among studies in which treatment was initiated presymptomatically, the weighted mean differences (WMDs) comparing the active treatment to control treated animals were 12 days (onset), 13 days (survival) and 5 days (survival interval). Among studies in which treatment was initiated at the time of symptom onset, the WMDs were 15 days (survival) and 8 days (survival interval). Subgroup analysis suggests that drugs such as minocycline and Cox-2 inhibitors with an anti-inflammatory mechanism of action, and anti-oxidative agents such as creatine or the manganese porphyrin AEOL-10150, appear to be the most promising for preventative and therapeutic trials respectively in patients with familial ALS. These conclusions should be tempered by the methodological limitations of the relevant literature.