A variety of common and rare genetic factors have been implicated in the development of amyotrophic lateral sclerosis (ALS), and the evidence is that a genetic component is present in most affected individuals. However, our current understanding of ALS genetics causally explains only a small proportion of sporadic ALS, which accounts for over 90

Background Despite several studies suggesting a potential oligogenic risk model in amyotrophic lateral sclerosis (ALS), case–control statistical evidence implicating oligogenicity with disease risk or clinical outcomes is limited. Considering its direct clinical and therapeutic implications, we aim to perform a large-scale robust investigation of oligogenicity in ALS risk and in the disease clinical course. Methods We leveraged Project MinE genome sequencing datasets (6711 cases and 2391 controls) to identify associations between oligogenicity in known ALS genes and disease risk, as well as clinical outcomes. Results In both the discovery and replication cohorts, we observed that the risk imparted from carrying multiple ALS rare variants was significantly greater than the risk associated with carrying only a single rare variant, both in the presence and absence of variants in the most well-established ALS genes. However, in contrast to risk, the relationships between oligogenicity and ALS clinical outcomes, such as age of onset and survival, did not follow the same pattern. Conclusions Our findings represent the first large-scale, case–control assessment of oligogenicity in ALS and show that oligogenic events involving known ALS risk genes are relevant for disease risk in ~6% of ALS but not necessarily for disease onset and survival. This must be considered in genetic counselling and testing by ensuring to use comprehensive gene panels even when a pathogenic variant has already been identified. Moreover, in the age of stratified medication and gene therapy, it supports the need for a complete genetic profile for the correct choice of therapy in all ALS patients.

ABSTRACT:Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting primarily the motor system. However, an association with sensory neuronopathy has been scarcely described. We described 3 unrelated patients (2 males) with sporadic spinal-onset ALS and sensory neuronopathy. Mean onset age was 63.7 years and mean Revised Amyotrophic Lateral Sclerosis Functional Rating Scale at diagnosis was 42. Sensory disturbances emerged before or overlap with motor symptoms in the same onset region and followed the same pattern of lower motor neuron involvement over disease progression. Two patients have also bilateral trigeminal sensory fibers affection. None had cognitive abnormalities. Genetic testing for the most common ALS-associated genes was unrevealing. Mean disease duration and ALS functional rating scale-revised at last visit was 47 months and 27, respectively. One patient is still alive, dependent on nocturnal noninvasive ventilation. Motor neuron disease is now considered a multisystem neurodegenerative disorder, and sensory neuronopathy, although very rare, should not be neglected as a possible part of the disease spectrum.

A variety of common and rare genetic factors have been implicated in the development of amyotrophic lateral sclerosis (ALS), and the evidence is that a genetic component is present in most affected individuals. However, our current understanding of ALS genetics causally explains only a small proportion of sporadic cases which represent over 90% of all people with ALS. This limits the utility of genetic testing in screening, diagnosis and management to the 15-20% of people with ALS who carry a known pathogenic variant. Capsule Networks (CapsNets) constitute a deep learning method that has demonstrated strong performance in using genotyping data to predict individuals at risk for ALS. However, their use is constrained by a lack of generalised, flexible, and validated implementations across comprehensive datasets that account for the technical, biological, and clinical heterogeneity found in real-world disease scenarios. In this study, we build upon this method to address existing limitations, to develop a new model that is validated across diverse ALS populations, can handle discrepancies between genotyping technologies, and is applicable to individual external samples. Using large-scale datasets from over 47,000 individuals from 13 countries, genotyped with nine different genotyping platforms, our model achieved high precision and sensitivity in distinguishing between individuals with ALS and non-affected controls. Moreover, in simulations of population screening for ALS, its performance was comparable to that of conventional genetic screening for known ALS gene mutations, such as FUS and C9orf72. Our results demonstrate that this flexible and validated method could support the development of a genetic screening test for identifying individuals at risk and expediting ALS diagnosis. This would be applicable to all individuals, regardless of their family history or presence of known ALS mutations. ### Competing Interest Statement VS received compensation for consulting services and/or speaking activities from AveXis, Cytokinetics, Italfarmaco, Liquidweb S.r.l., Amylyx, Novartis Pharma AG, Zambon Biotech SA, and Biogen. VS is in the Editorial Board of Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, European Neurology, American Journal of Neurodegenerative Diseases, Frontiers in Neurology, and Exploration of Neuroprotective Therapy. AAC reports receiving nonfinancial support from the National Institute for Health and Care Research (NIHR); consultant fees from Amylyx, Clene Therapeutics, GenieUs, GSK, Eli Lilly, Mitsubishi Tanabe Pharma, Novartis, OrionPharma, Quralis, SanoGenetics, Sanofi, Voyager Therapeutics, and Wave Pharmaceuticals; and having a patent for use of CSF-neurofilament determinations and CSF-neurofilament thresholds of prognostic and stratification value with regards to response to therapy in neuromuscular and neurodegenerative diseases pending. ### Funding Statement This is an EU Joint Programme-Neurodegenerative Disease Research (JPND) project. The project is supported through the following funding organisations under the aegis of JPND http://www.neurodegenerationresearchneurodegenerati onresearch.eu/ (UK, Medical Research Council (MR/L501529/1 and MR/R024804/1) and Economic and Social Research Council (ES/L008238/1). AA-C is an NIHR Senior Investigator. AA-C receives salary support from the National Institute for Health and Care Research (NIHR) Dementia Biomedical Research Unit at South London and Maudsley NHS Foundation Trust and King's College London. The work leading up to this publication was funded by the European Community's Health Seventh Framework Program (FP7/2007-2013; grant agreement number 259867) and Horizon 2020 Program (H2020-PHC-2014-two-stage; grant agreement number 633413). This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (grant agreement no. 772376-EScORIAL. This study represents independent research part funded by the NIHR Maudsley Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London. AI is funded by South London and Maudsley NHS Foundation Trust, MND Scotland, Motor Neurone Disease Association, National Institute for Health and Care Research, Spastic Paraplegia Foundation, Rosetrees Trust, Darby Rimmer MND Foundation, the Medical Research Council (UKRI), LifeArc, and Alzheimer's Research UK. Project MinE Belgium was supported by a grant from IWT (n 140935), the ALS Liga Belgie, the National Lottery of Belgium and the KU Leuven Opening the Future Fund. AAK is funded by The Motor Neurone Disease Association (MNDA), NIHR Maudsley Biomedical Research Centre and ALS Association Milton Safenowitz Research Fellowship, the Darby Rimmer MND Foundation, LifeArc, and the Dementia Consortium. AAK is supported by the UK Dementia Research Institute through UK DRI Ltd, principally funded by the Medical Research Council. VS Receives or has received research supports from the Italian Ministry of Health, AriSLA, E-Rare Joint Transnational Call, and the ERN Euro-NMD. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The datasets used in your study were individual-level data all individual-level data had been de-identified. All data used in this study are publicly available. The ALS genome data and GWAS data used in this study are from Project MinE and can be accessed via online application (www.projectmine.com). Other data utilized in this study include the following: the Wellcome Trust Case Control Consortium (https://www.wtccc.org.uk/) and dbGaP datasets (phs000101.v3.p1, phs000101.v3.p1, phs000101.v3.p1, phs000101.v3.p1, phs000126.v1.p1, phs000196.v1.p1, phs000344.v1.p1, phs000344.v1.p1, phs000344.v1.p1). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data used in this study are publicly available. The ALS genome data and GWAS data used in this study are from Project MinE and can be accessed via online application (www.projectmine.com). Other data utilized in this study include the following: the Wellcome Trust Case Control Consortium (https://www.wtccc.org.uk/) and dbGaP datasets (phs000101.v3.p1, phs000101.v3.p1, phs000101.v3.p1, phs000101.v3.p1, phs000126.v1.p1, phs000196.v1.p1, phs000344.v1.p1, phs000344.v1.p1, phs000344.v1.p1).

BACKGROUND:C9orf72 gene repeat expansion (C9RE) is the most frequent gene variant associated with amyotrophic lateral sclerosis (ALS). We aimed to study the phenotype of motor neurone disease (MND) patients with C9RE in a Portuguese cohort. METHODS:Demographical and clinical data of MND patients with (C9RE+) and without C9RE were compared. ALS al Rating Scale-Revised (ALSFRS-R) and Edinburgh Cognitive and Behavioural ALS Screen (ECAS) were used to evaluate functional and cognitive performance, respectively. Survival analysis was performed using Kaplan Meier log-rank test and Cox proportional hazards model. RESULTS:We included 761 patients of whom 61 (8.0 %) were C9RE+. C9RE+ patients had a higher frequency of ALS (95.1 vs 78.4 %, p = 0.002), and lower frequency of progressive muscular atrophy (3.3 vs 16.7 %, p = 0.006). C9RE+ was associated with earlier age of onset (58.1 vs 62.6 years, p = 0.003) and more frequent MND family history (65.5 vs 11.4 %, p < 0.001). Gender, ethnicity, onset site, diagnostic delay, disease progression rate until diagnosis (ΔF), ALSFRS-R and time until non-invasive ventilation did not differ between groups. Cognitive/behavioural symptoms and ECAS did not differ between groups, except a worse visuospatial score in C9RE+ group (p = 0.035). Death rate was 1.8 and 1.6 times higher in C9RE+ patients with MND and ALS, respectively. Significant survival prognostic factors in C9RE+ group were diagnosis delay (HR = 0.96, 95 %CI 0.92-0.99, p = 0.008) and ΔF (HR = 1.93, 95 %CI 1.26-2.96, p = 0.002). CONCLUSION:Our study corroborates most previous cohorts' findings, but harbours some singularities regarding onset site, phenotype, and cognitive profile, that contribute to a better understanding of C9RE epidemiology.

BACKGROUND:The rate of disease progression, measured by the decline of ALS Functional Rating Scale-Revised (ALSFRS-R) from symptom onset to diagnosis (ΔFS) is a well-established prognostic biomarker for predicting survival. Objectives: This study aims to categorize a large patient cohort based on the initial ΔFS and subsequently investigate survival deviations from the expected prognosis defined by ΔFS. METHODS:1056 ALS patients were stratified into three progression categories based on their ΔFS: slow progressors (below 25th percentile), intermediate progressors (between 25th and 75th percentiles), and fast progressors (above 75th percentile). Survival outcomes were classified as short survivors (<2 years), average survivors (2-5 years), and long survivors (>5 years). Clinical and demographic characteristics within each subgroup were then analyzed. RESULTS:ΔFS stratification yielded cutoff values of <0.29, 0.29-1.03, and >1.03 points/month. Long survivors comprised 26% and 21% were short survivors. Six percent of the fast progressors had a life expectancy of more than 5 years, and none of the clinical and demographic characteristics analyzed could fully explain this discrepancy. Conversely, 13% of intermediate progressors lived less than 2 years, according to a short-diagnostic delay in these patients. DISCUSSION:Our study reaffirms ΔFS as a prognostic biomarker for ALS. We disclosed outliers defying anticipated patterns. The observed shift in progression categories underscores the non-linear nature of disease progression. Genetic and unknown biological reasons may explain these deviations. Further research is needed to fully understand modulation of ALS survival.

ABSTRACT Objective Genetic variation in the neurofilament heavy chain gene ( NEFH ) has been convincingly linked to the pathogenesis of multiple neurodegenerative diseases, however, the relationship between NEFH mutations and ALS susceptibility has not been robustly explored. We therefore wanted to determine if genetic variants in NEFH modify ALS risk. Methods We performed fixed and random effects model meta-analysis of published case-control studies reporting NEFH variant frequencies using next-generation sequencing, microarray or PCR-based approaches. Comprehensive screening and rare variant burden analysis of NEFH variation in the Project MinE ALS whole-genome sequencing data set was also conducted. Results We identified 12 case-control studies that reported NEFH variant frequencies, for a total of 9,496 samples (4,527 ALS cases and 4,969 controls). Fixed effects meta-analysis found that rare (MAF<1%) missense variants in the tail domain of NEFH increase ALS risk (OR 4.56, 95% CI 2.13-9.72, p<0.0001). A total of 591 rare NEFH variants, mostly novel (78.2%), were found in the Project MinE dataset (8,903 samples: 6,469 cases and 2,434 controls). Burden analysis showed ultra-rare (MAF <0.1%) pathogenic missense variants in the tail domain are associated with ALS (OR 1.94, 95% CI 0.86-4.37, Madsen-Browning p=0.039), replicating and confirming the meta-analysis finding. High-frequency rare (MAF 0.1-1%) tail in-frame deletions also confer susceptibility to ALS (OR 1.18, 95% CI 0.67-2.07, SKAT-O p=0.03), which supports previous findings. Interpretation This study shows that NEFH tail domain variants are a risk factor of ALS and supports the inclusion of missense and in-frame deletion NEFH variants in ALS genetic screening panels.

Recently, large-scale case-control analyses have been prioritized in the study of ALS. Yet the same effort has not been put forward to investigate additive moderate phenotypic effects of genetic variants in genes driving ALS risk, despite case-level evidence suggesting a potential oligogenic risk model. Considering its direct clinical and therapeutic implications, a large-scale robust investigation of oligogenicity in ALS is greatly needed. Here, we leveraged the Project MinE ALS Sequencing Consortium genome sequencing datasets of individuals with ALS (n = 6711) and controls (n = 2391) to identify signals of association between oligogenicity in known ALS genes (n=26) and disease risk, as well as clinical outcomes. Applying regression models to a discovery and replication cohort, we observed that the risk imparted from carrying rare variants in multiple known ALS genes was significant and was greater than the risk associated with carrying only a single rare variant, both in the presence and absence of variants in the most well-established ALS genes, such as C9orf72 . However, in contrast to risk, the relationships between oligogenicity and ALS clinical outcomes, such as age of onset and survival, might not follow the same pattern as we did not observe any associations. Our findings represent the first large-scale, case-control assessment of oligogenic associations in ALS to date and confirm that oligogenic events involving known ALS risk genes are indeed relevant for the risk of disease in approximately 6% of ALS but not necessarily for disease onset and survival. This must be considered in genetic counselling and testing by ensuring the use of comprehensive gene panels even when a potential pathogenic variant has already been identified. Moreover, in the age of stratified medication and gene therapy, it supports the need of a complete genetic profile for the correct choice of therapy in all ALS patients. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This is an EU Joint Programme Neurodegenerative Disease Research (JPND) project. The project is supported through the following funding organizations under the aegis of JPND http://www.neurodegenerationresearch.eu/ [United Kingdom, Medical Research Council (MR/L501529/1 and MR/R024804/1) and Economic and Social Research Council (ES/L008238/1)]. AAC is a NIHR Senior Investigator. AAC receives salary support from the National Institute for Health and Care Research (NIHR) Dementia Biomedical Research Unit at South London and Maudsley NHS Foundation Trust and King's College London. The work leading up to this publication was funded by the European Community's Health Seventh Framework Program (FP7/2007 2013; grant agreement number 259867) and Horizon 2020 Program (H2020-PHC-2014-two-stage; grant agreement number 633413). This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (grant agreement no. 772376 EScORIAL. This study represents independent research part funded by the NIHR Maudsley Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, King's College London, or the Department of Health and Social Care. AAD is supported by the Canadian Institute of Health Research Banting Postdoctoral Fellowship Program. AI is funded by South London and Maudsley NHS Foundation Trust, MND Scotland, Motor Neurone Disease Association, National Institute for Health and Care Research, Spastic Paraplegia Foundation, Rosetrees Trust, Darby Rimmer MND Foundation, the Medical Research Council (UKRI) and Alzheimer's Research UK. SMKF is supported by grants from ALS Canada, Brain Canada, the Michael J. Fox Foundation, and the Montreal Neurological Institute Hospital. Project MinE Belgium was supported by a grant from IWT (n 140935), the ALS Liga Belgie, the National Lottery of Belgium and the KU Leuven Opening the Future Fund. AAK is funded by the ALS Association Milton Safenowitz Research Fellowship, The Motor Neurone Disease Association (MNDA) Fellowship, The Darby Rimmer Foundation, and The NIHR Maudsley Biomedical Research Centre. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Individual whole-genome sequencing data are available and can be requested through Project MinE (<https://www.projectmine.com/research/data-sharing/>). A data access committee controls access to raw data, ensuring a FAIR data setup (<https://www.datafairport.org>). Details on the frequencies and gene burden test results are available on the ProjectMinE databrowser [29][1] (<http://databrowser.projectmine.com>). [1]: #ref-29

Objective To describe the clinical features and progression of patients with respiratory onset amyotrophic lateral sclerosis (ALS). Methods: We analyzed the clinical features, including respiratory tests, functional score, noninvasive ventilation (NIV) time and survival of ALS patients with respiratory-onset in our database consisting of 1688 patients. In a subset of 625 ALS patients we analyzed the spreading pattern to other bodily regions. Results: We included 1579 patients with ALS. Sixty-three patients (4%) presented respiratory-onset (79.4% men, mean onset-age 67.7 +/- 8.9yrs). All had predominant LMN involvement, and significant weight loss (>10%) was identified in 38.9%. The respiratory tests were abnormal in these respiratory-onset patients (p < 0.001). ALSFRS-R respiratory subscore was lower in this population (p < 0.001). NIV was adapted in 84.1%, sooner than in the larger group of ALS patients (p < 0.001), and survival from disease onset was shorter (p < 0.001). Respiratory-onset was a predictor of time to NIV (X-2=42.0, p < 0.001) and of survival (X-2=7.1, p = 0.008). The spreading pattern was studied in 18 patients with isolated respiratory-onset. The progression interval to the 2nd region was 4.7 +/- 5.7mo and to a 3rd region 6.1 +/- 8.7mo. Different patterns of spread had no impact on survival. Conclusions: This phenotype is typically seen in emaciated older men with predominant lower motor neuron involvement, and is associated with diaphragm paresis and central respiratory involvement. NIV adaptation is rapid but total survival is shorter than in the other patients. Spreading pattern did not affect time to NIV adaptation or total survival, as NIV support is a modifying treatment in the course of ALS.

ABSTRACT Primary lateral sclerosis (PLS) is the rarest form of motor neurone disease (MND). It is characterized by upper motor neuron degeneration, leading to progressive weakness, spasticity and functional disability. Although PLS does not typically shorten life substantially, it gradually impacts quality of life as the diseases progresses. There is no established genetic cause of PLS. One of the biggest challenges faced by people with PLS is delayed diagnosis and misdiagnosis, since the initial symptoms can be similar to amyotrophic lateral sclerosis (ALS), the most common form of MND. In the absence of a concrete genetic test that differentiates PLS from other MNDs, this delay in diagnosis is inevitable. Understanding the genetic basis of PLS might help in reducing the time from the onset of symptoms to diagnosis, and it will improve our understanding of the disease biology favouring the development of a treatment. The aim of our study is to collect a large international PLS genetic and clinical dataset to investigate its genetic and phenotypic landscapes as well as to evaluate whether genetic testing should be advised in PLS. Through Project MinE and AnswerALS, we accessed whole-genome sequencing data of 120 PLS, 7405 ALS and 2444 controls. We identified variants in several MND genes such as FIG4, FUS, SPG7, SPG11 and SQSTM1 genes among others and repeat expansions in the ATXN1 (12.2%) and NIPA1 (7.3%) genes, but none in the C9orf72 and ATXN2 genes. Overall PLS patients harboured fewer clinically actionable MND-associated variants than ALS patients (p = 0.0001), however, depending on the panel, up to 11% of people with PLS might benefit from genetic testing. By looking at the clinical characteristics of these cohorts, the age of symptom onset was not younger for people with PLS than for those with ALS in both Project MinE and AnswerALS. On such bases, we advise that the current diagnostic criteria that discourage the use of genetic testing and rely on age of onset should be reconsidered.

Respiratory insufficiency and its complications are the main cause of death in amyotrophic lateral sclerosis (ALS). Respiratory symptoms are scored in questions Q10 (dyspnoea) and Q11 (orthopnoea) of the Amyotrophic Lateral Sclerosis Functional Rating Scale–Revised (ALSFRS‐R). The association of respiratory test alterations with respiratory symptoms is unclear.

Abstract Objective Motor Neuron Diseases (MND) have a large clinical spectrum, being the most common amyotrophic lateral sclerosis (ALS) but there is significant clinical heterogeneity. Our goal was to investigate this heterogeneity and any potential changes during a long period. Methods We performed a retrospective cohort study among a large Portuguese cohort of MND patients (n = 1550) and investigated changing patterns in clinical and demographic characteristics over the 27-year period of our database. With that aim, patients were divided into three 9-year groups according to the date of their first visit to our unit: P1, 1994–2002; P2, 2003–2011; P3, 2012–2020. Results The overall cohort’s clinical and demographic characteristics are consistent with clinical experience, but our findings point to gradual changes over time. Time pattern analysis revealed statistically significant differences in the distribution of clinical phenotypes, the average age of onset, diagnostic delay, the proportin of patients using respiratory support with noninvasive ventilation (NIV), time to NIV, and survival. Across time, in the overall cohort, we found an increasing age at onset (p = 0.029), a decrease of two months in diagnostic delay (p < 0.001) and a higher relative frequency of progressive muscular atrophy patients. For ALS patients with spinal onset, from P1 to P2, there was a more widespread (54.8% vs 69.4%, p = 0.005) and earlier (36.9 vs 27.2 months, p = 0.05) use of NIV and a noteworthy 13-month increase in median survival (p = 0.041). Conclusions Our results probably reflect better comprehensive care, and they are relevant for future studies exploring the impact of new treatments on ALS patients.

Background Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease with a median survival of 2–5 years. An early diagnosis is essential for providing ALS patients the finest management possible. Studies from different countries report a similar median diagnostic delay of around 12 months, which is still far from desirable. We analyzed the diagnostic pathway in different countries in order to identify the major challenges. Methods We studied a cohort of 1,405 ALS patients from five different centers, in four different countries (Turkey, Germany, Poland, and Portugal), which collaborated in a common database. Demographic, disease and sociocultural factors were collected. Time from first symptom onset to first medical evaluation and to diagnosis, the specialist assessment and investigations requested were analyzed. Factors contributing to diagnostic delay were evaluated by multivariate linear regression. Results The median diagnostic delay from first symptom onset was 11 months and was similar between centers. Major differences were seen in the time from symptom onset to first medical evaluation. An earlier first medical evaluation was associated with a longer time to diagnosis, highlighting that ALS diagnosis is not straightforward in the early stages of the disease. The odds for ALS diagnosis were superior when evaluated by a neurologist and increased over time. Electromyography was decisive in establishing the diagnosis. Conclusions We suggest that a specific diagnostic test for ALS—a specific biomarker—will be needed to achieve early diagnosis. Early referral to a neurologist and to electromyography is important for early ALS diagnosis.

"Determining the need for caregiver support using ALSFRS-R and its limitations." Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, ahead-of-print(ahead-of-print), pp. 1–2

Abstract Objective: The flail-arm syndrome (FAS), one of the Amyotrophic lateral sclerosis (ALS) phenotypes, is characterized by slow progression and predominantly lower motor neuron (LMN) involvement with proximal upper limb (UL) weakness. We aim to characterize the clinical features, progression and survival of FAS associated with distal or proximal onset and presence or absence of upper motor neuron signs (UMN) signs at diagnosis. Methods: Data from 704 ALS patients was analyzed. Of the 190 patients with UL onset; 134 were excluded as not respecting the published criteria for FAS. The included patients were divided into four groups according to distal/proximal onset and presence/absence of UMN signs. Results: 56 FAS patients (8% of the population), median age at onset 59.9 years (Q1/Q3, 50.3–68.1), 75% men, were studied. Distal onset with UMN signs occurred in 37.5%, distal onset without UMN signs in 28.6%, proximal onset with UMN signs in 8.9% and proximal onset without UMN signs in 25%. Age of onset, sex, fasciculations at onset, diagnostic delay, progression rate, time to respiratory involvement and survival were similar among the four groups. Sex ratio was more balanced in patients with UMN signs (p = 0.032) and survival was shorter (69.5 months, 95% CI: 55.4–110.4 vs 152.6 months, 95% CI: 69.0–177.3; p = 0.035). The Cox regression identified rate of progression (p < 0.001) and UMN signs (p = 0.003) as independent predictors of shorter survival. Conclusions: Distal or proximal onset had no influence on clinical characteristics and prognosis but UMN signs at diagnosis are a negative prognostic predictor.

Introduction: Caveolin-1 and Caveolin-2 (CAV1 and CAV2) are proteins associated with intercellular neurotrophic signalling. There is converging evidence that CAV1 and CAV2 (CAV1/2) genes have a role in amyotrophic lateral sclerosis (ALS). Disease-associated variants have been identified within CAV1/2 enhancers, which reduce gene expression and lead to disruption of membrane lipid rafts. Methods: Using large ALS whole-genome sequencing and post-mortem RNA sequencing datasets (5,987 and 365 tissue samples, respectively), and iPSC-derived motor neurons from 55 individuals, we investigated the role of CAV1/2 expression and enhancer variants in the ALS phenotype. Results: We report a differential expression analysis between ALS cases and controls for CAV1 and CAV2 genes across various post-mortem brain tissues and three independent datasets. CAV1 and CAV2 expression was consistently higher in ALS patients compared to controls, with significant results across the primary motor cortex, lateral motor cortex, and cerebellum. We also identify increased survival among carriers of CAV1/2 enhancer mutations compared to non-carriers within Project MinE and slower progression as measured by the ALSFRS. Carriers showed a median increase in survival of 345 days. Discussion: These results add to an increasing body of evidence linking CAV1 and CAV2 genes to ALS. We propose that carriers of CAV1/2 enhancer mutations may be conceptualised as an ALS subtype who present a less severe ALS phenotype with a longer survival duration and slower progression. Upregulation of CAV1/2 genes in ALS cases may indicate a causal pathway or a compensatory mechanism. Given prior research supporting the beneficial role of CAV1/2 expression in ALS patients, we consider a compensatory mechanism to better fit the available evidence, although further investigation into the biological pathways associated with CAV1/2 is needed to support this conclusion.

BACKGROUND AND PURPOSE Respiratory insufficiency and its complications are the main cause of death in amyotrophic lateral sclerosis (ALS). The impact of diabetes mellitus (DM) on respiratory function of ALS patients is uncertain. METHODS A retrospective cohort study was carried out. From the 1710 patients with motor neuron disease followed in our unit, ALS and progressive muscular atrophy patients were included. We recorded demographic characteristics, functional ALS rating scale (Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised [ALSFRS-R]) and its subscores at first visit, respiratory function tests, arterial blood gases, phrenic nerve amplitude (PhrenAmpl), and mean nocturnal oxygen saturation (SpO2 mean). We excluded patients with other relevant diseases. Two subgroups were analysed: DIAB (patients with DM) and noDIAB (patients without DM). Independent t-test, χ2 , or Fisher exact test was applied. Binomial logistic regression analyses assessed DM effects. Kaplan-Meier analysis assessed survival. p < 0.05 was considered significant. RESULTS We included 1639 patients (922 men, mean onset age = 62.5 ± 12.6 years, mean disease duration = 18.1 ± 22.0 months). Mean survival was 43.3 ± 40.7 months. More men had DM (p = 0.021). Disease duration was similar between groups (p = 0.063). Time to noninvasive ventilation (NIV) was shorter in DIAB (p = 0.004); total survival was similar. No differences were seen for ALSFRS-R or its decay rate. At entry, DIAB patients were older (p < 0.001), with lower forced vital capacity (p = 0.001), arterial oxygen pressure (p = 0.01), PhrenAmpl (p < 0.001), and SpO2 mean (p = 0.014). CONCLUSIONS ALS patients with DM had increased risk of respiratory impairment and should be closely monitored. Early NIV allowed for similar survival rate between groups.

Abstract Background: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterised by a highly variable clinical presentation and multifaceted genetic and biological bases that translate into great patient heterogeneity. The identification of homogeneous subgroups of patients in terms of both clinical presentation and biological causes, could favour the development of effective treatments, healthcare, and clinical trials. We aimed to identify and characterise homogenous clinical subgroups of ALS, examining whether they represent underlying biological trends. Methods: Latent class clustering analysis, an unsupervised machine-learning method, was used to identify homogenous subpopulations in 6,523 people with ALS from Project MinE, using widely collected ALS-related clinical variables. The clusters were validated using 7,829 independent patients from STRENGTH. We tested whether the identified subgroups were associated with biological trends in genetic variation across genes previously linked to ALS, polygenic risk scores of ALS and related neuropsychiatric traits, and in gene expression data from post-mortem motor cortex samples. Results: We identified five ALS subgroups based on patterns in clinical data which were general across international datasets. Distinct genetic trends were observed for rare variants in the SOD1 and C9orf72 genes, and across genes implicated in biological processes relevant to ALS. Polygenic risk scores of ALS, schizophrenia and Parkinson's disease were also higher in distinct clusters with respect to controls. Gene expression analysis identified different altered biological processes across clusters reflecting the genetic differences. We developed a machine learning classifier based on our model to assign subgroup membership using clinical data available at first visit, and made it available on a public webserver at http://latentclusterals.er.kcl.ac.uk. Conclusion: ALS subgroups characterised by highly distinct clinical presentations were discovered and validated in two large independent international datasets. Such groups were also characterised by different underlying genetic architectures and biology. Our results showed that data-driven patient stratification into more clinically and biologically homogeneous subtypes of ALS is possible and could help develop more effective and targeted approaches to the biomedical and clinical study of ALS.