To investigate whether antidiabetic drugs have a biological basis to be repurposed in PD prevention, we applied a drug target Mendelian randomization framework to assess associations between genetic variation in antidiabetic drug targets and PD risk or age at onset (AAO). Instrumental variables (IVs) were derived from GWAS summary statistics on fasting glucose (FG), glycated hemoglobin (HbA1c), and gene expression data from GTEx. Apart from SGLT2 inhibitors, all other antidiabetic drugs of interest could be instrumented through our methods. Positive and negative control analyses were carried out to validate 20 IVs in the FG arm and 23 IVs in the HbA1c arm. DPP-4 inhibitors failed the positive control. GWAS summary statistics for PD risk and AAO data were sourced from the IPDGC and COURAGE-PD consortia, resulting in 42 083 cases/457 090 controls for risk and 37 103 PD cases for AAO. MR analyses showed no significant associations across consortia or in meta-analysis. These findings do not support a causal role of genetic variation in antidiabetic drug targets in PD risk or AAO.

We investigated the role of copy number variations (CNVs) in Parkinson's disease (PD) using genotyping data from 10,815 patients (2731 early-onset PD, EOPD) and 8901 controls from the COURAGE-PD consortium. CNVs were analyzed using a sliding window genome-wide association and burden approach. No genome-wide significant CNVs were detected in the overall cohort, but a robust deletion spanning exons 2-6 of PRKN was identified in EOPD cases, validated by MLPA, and replicated in the GP2 dataset (23,089 cases, 18,824 controls). CNV burden was significantly enriched in PD-related genes, primarily driven by PRKN, with the strongest effect observed in EOPD. PRKN CNV carriers showed earlier age at onset, confirmed by survival analysis. No association was observed for genome-wide or large CNV burden. Our findings reinforce the pivotal role of PRKN deletions in early-onset PD and highlight the need for high-resolution CNV analysis in large cohorts to uncover additional rare contributors to PD risk.

Amyotrophic lateral sclerosis (ALS) is a heritable disorder where rare variants with low-to-moderate penetrance are thought to dominate genetic risk. To identify such rare variants, we harmonized and analyzed exome data from 22 cohorts, totaling 17,919 individuals with ALS and 200,703 controls across discovery and replication phases. Rare variant analyses identified several new risk genes, with replication confirming association of YKT6 and supporting HTR3C, GBGT1 and KNTC1. We also provide strong, independent validation for genes with limited previous evidence: ARPP21, DNAJC7 and CFAP410. Notably, in ARPP21, we identified a new high-effect variant (p.P747L) and confirmed that p.P563L is an ALS-associated variant leading to an aggressive disease course. Beyond new discoveries, our analyses largely recapitulated the known genetic architecture of ALS, identifying risk variants in over 20% of cases and supporting a cumulative oligogenic risk model. These findings highlight new translational targets and show that rare variant analyses capture substantially more genetic risk than common variant genome-wide association studies.

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.

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).

Objective:To investigate the impact of copy number variations (CNVs) on Parkinson's disease (PD) pathogenesis using genome-wide data and explore their role in sporadic PD. Methods:We analyzed CNV data from 11,035 PD patients (including 2,731 early-onset PD (EOPD)) and 8,901 controls from the COURAGE-PD consortium using a sliding window CNV-GWAS and genome-wide burden analysis. The independent dataset from the Global Parkinson Genetics Program (GP2) consisted of 23,089 cases and 18,824 controls were used to validate our initial findings. Results:The exploratory dataset identifies multiple CNV regions associated with PD risk. The nominated CNV loci were not confirmed in an independent dataset, except that only a deletion in the PRKN gene, a well-established EOPD locus, remained genome-wide significant and robustly supported. CNV burden analysis showed a higher prevalence of CNVs in PD-related genes in patients compared to controls (OR=1.56 [1.18-2.09], p=0.0013), with PRKN showing the highest burden (OR=1.47 [1.10-1.98], p=0.026). Patients with CNVs in PRKN had an earlier disease onset. Burden analysis with controls and EOPD patients showed similar results. Interpretation:The largest CNV-based GWAS on PD highlights both the promise and pitfalls of array-based CNV detection in PD and underscores the relevance of whole-genome sequencing approaches in resolving the role of CNV in PD. The array-based findings are prone towards false positive findings that might arise either from platform limitations and/or cohort biases. Future studies require improved genotyping resolution and rigorous cross-cohort validation to reliably assess CNV contributions to PD risk.

Introduction Wolfram syndrome (WFS1-Spectrum Disorder) is an ultra-rare monogenic form of progressive neurodegeneration and diabetes mellitus. In common with most rare diseases, there are no therapies to slow or stop disease progression. Sodium valproate, an anticonvulsant with neuroprotective properties, is anticipated to mediate its effect via alteration of cell cycle kinetics, increases in p21cip1 expression levels and reduction in apoptosis and increase in Wolframin protein expression. To date, there have been no multicentre randomised controlled trials investigating the efficacy of treatments for neurodegeneration in patients with Wolfram syndrome.Methods and analysis TREATWOLFRAM is an international, multicentre, double-blind, placebo-controlled, randomised clinical trial designed to investigate whether 36-month treatment with up to 40 mg/kg/day of sodium valproate will slow the rate of loss of visual acuity as a biomarker for neurodegeneration in patients with Wolfram syndrome. Patients who satisfied the eligibility criteria were randomly assigned (2:1) to receive two times per day oral gastro-resistant sodium valproate tablets up to a maximum dose of 800 mg 12 hourly or sodium valproate-matched placebo. Using hierarchical repeated measures analyses with a 5% significance level, 80% power and accounting for an estimated 15% missing data rate, a sample size of 70 was set. The primary outcome measure, visual acuity, will be centrally reviewed and analysed on an intention-to-treat population.Ethics and dissemination The protocol was approved by the National Research Ethics Service (West of Scotland; 18/WS/0020) and by the Medicines and Healthcare products Regulatory Agency. Recruitment into TREATWOLFRAM started in January 2019 and ended in November 2021. The treatment follow-up of TREATWOLFRAM participants is ongoing and due to finish in November 2024. Updates on trial progress are disseminated via Wolfram Syndrome UK quarterly newsletters and at family conferences for patient support groups. The findings of this trial will be disseminated through peer-reviewed publications and international presentations.Trial registration number NCT03717909.

Background and Objectives The role of body mass index (BMI) in Parkinson disease (PD) is unclear. Based on the Comprehensive Unbiased Risk Factor Assessment for Genetics and Environment in PD (Courage-PD) consortium, we used 2-sample Mendelian randomization (MR) to replicate a previously reported inverse association of genetically predicted BMI with PD and investigated whether findings were robust in analyses addressing the potential for survival and incidence-prevalence biases. We also examined whether the BMI-PD relation is bidirectional by performing a reverse MR. Methods We used summary statistics from a genome-wide association study (GWAS) to extract the association of 501 single-nucleotide polymorphisms (SNPs) with BMI and from the Courage-PD and international Parkinson Disease Genomics Consortium (iPDGC) to estimate their association with PD. Analyses are based on participants of European ancestry. We used the inverse-weighted method to compute odds ratios (ORIVW per 4.8 kg/m(2) [95% CI]) of PD and additional pleiotropy robust methods. We performed analyses stratified by age, disease duration, and sex. For reverse MR, we used SNPs associated with PD from 2 iPDGC GWAS to assess the effect of genetic liability toward PD on BMI. Results Summary statistics for BMI are based on 806,834 participants (54% women). Summary statistics for PD are based on 8,919 (40% women) cases and 7,600 (55% women) controls from Courage-PD, and 19,438 (38% women) cases and 24,388 (51% women) controls from iPDGC. In Courage-PD, we found an inverse association between genetically predicted BMI and PD (ORIVW 0.82 [0.70-0.97], p = 0.012) without evidence for pleiotropy. This association tended to be stronger in younger participants (<= 67 years, ORIVW 0.71 [0.55-0.92]) and cases with shorter disease duration (<= 7 years, ORIVW 0.75 [0.62-0.91]). In pooled Courage-PD + iPDGC analyses, the association was stronger in women (ORIVW 0.85 [0.74-0.99], p = 0.032) than men (ORIVW 0.92 [0.80-1.04], p = 0.18), but the interaction was not statistically significant (p-interaction = 0.48). In reverse MR, there was evidence for pleiotropy, but pleiotropy robust methods showed a significant inverse association. Discussion Using an independent data set (Courage-PD), we replicate an inverse association of genetically predicted BMI with PD, not explained by survival or incidence-prevalence biases. Moreover, reverse MR analyses support an inverse association between genetic liability toward PD and BMI, in favor of a bidirectional relation.

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.

Repeat expansions in the C9orf72 gene are the most common genetic cause of (ALS) and frontotemporal dementia (FTD). Like other genetic forms of neurodegeneration, pinpointing the precise mechanism(s) by which this mutation leads to neuronal death remains elusive, and this lack of knowledge hampers the development of therapy for C9orf72-related disease. We used an agnostic approach based on genomic data (n = 41,273 ALS and healthy samples, and n = 1,516 C9orf72 carriers) to overcome these bottlenecks. Our drug-repurposing screen, based on gene- and expression-pattern matching and information about the genetic variants influencing onset age among C9orf72 carriers, identified acamprosate, a γ-aminobutyric acid analog, as a potentially repurposable treatment for patients carrying C9orf72 repeat expansions. We validated its neuroprotective effect in cell models and showed comparable efficacy to riluzole, the current standard of care. Our work highlights the potential value of genomics in repurposing drugs in situations where the underlying pathomechanisms are inherently complex. VIDEO ABSTRACT.

The role of body mass index (BMI) in Parkinson disease (PD) is unclear. Based on the Comprehensive Unbiased Risk Factor Assessment for Genetics and Environment in PD (Courage-PD) consortium, we used 2-sample Mendelian randomization (MR) to replicate a previously reported inverse association of genetically predicted BMI with PD and investigated whether findings were robust in analyses addressing the potential for survival and incidence-prevalence biases. We also examined whether the BMI-PD relation is bidirectional by performing a reverse MR.

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

BACKGROUND AND OBJECTIVES:The role of body mass index (BMI) in Parkinson disease (PD) is unclear. Based on the Comprehensive Unbiased Risk Factor Assessment for Genetics and Environment in PD (Courage-PD) consortium, we used 2-sample Mendelian randomization (MR) to replicate a previously reported inverse association of genetically predicted BMI with PD and investigated whether findings were robust in analyses addressing the potential for survival and incidence-prevalence biases. We also examined whether the BMI-PD relation is bidirectional by performing a reverse MR. METHODS:We used summary statistics from a genome-wide association study (GWAS) to extract the association of 501 single-nucleotide polymorphisms (SNPs) with BMI and from the Courage-PD and international Parkinson Disease Genomics Consortium (iPDGC) to estimate their association with PD. Analyses are based on participants of European ancestry. We used the inverse-weighted method to compute odds ratios (ORIVW per 4.8 kg/m2 [95% CI]) of PD and additional pleiotropy robust methods. We performed analyses stratified by age, disease duration, and sex. For reverse MR, we used SNPs associated with PD from 2 iPDGC GWAS to assess the effect of genetic liability toward PD on BMI. RESULTS:Summary statistics for BMI are based on 806,834 participants (54% women). Summary statistics for PD are based on 8,919 (40% women) cases and 7,600 (55% women) controls from Courage-PD, and 19,438 (38% women) cases and 24,388 (51% women) controls from iPDGC. In Courage-PD, we found an inverse association between genetically predicted BMI and PD (ORIVW 0.82 [0.70-0.97], p = 0.012) without evidence for pleiotropy. This association tended to be stronger in younger participants (≤67 years, ORIVW 0.71 [0.55-0.92]) and cases with shorter disease duration (≤7 years, ORIVW 0.75 [0.62-0.91]). In pooled Courage-PD + iPDGC analyses, the association was stronger in women (ORIVW 0.85 [0.74-0.99], p = 0.032) than men (ORIVW 0.92 [0.80-1.04], p = 0.18), but the interaction was not statistically significant (p-interaction = 0.48). In reverse MR, there was evidence for pleiotropy, but pleiotropy robust methods showed a significant inverse association. DISCUSSION:Using an independent data set (Courage-PD), we replicate an inverse association of genetically predicted BMI with PD, not explained by survival or incidence-prevalence biases. Moreover, reverse MR analyses support an inverse association between genetic liability toward PD and BMI, in favor of a bidirectional relation.

Humans are thought to be more susceptible to neurodegeneration than equivalently-aged primates. It is not known whether this vulnerability is specific to anatomically-modern humans or shared with other hominids. The contribution of introgressed Neanderthal DNA to neurodegenerative disorders remains uncertain. It is also unclear how common variants associated with neurodegenerative disease risk are maintained by natural selection in the population despite their deleterious effects. In this study, we aimed to quantify the genome-wide contribution of Neanderthal introgression and positive selection to the heritability of complex neurodegenerative disorders to address these questions.We used stratified-linkage disequilibrium score regression to investigate the relationship between five SNP-based signatures of natural selection, reflecting different timepoints of evolution, and genome-wide associated variants of the three most prevalent neurodegenerative disorders: Alzheimer's disease, amyotrophic lateral sclerosis and Parkinson's disease.We found no evidence for enrichment of positively-selected SNPs in the heritability of Alzheimer's disease, amyotrophic lateral sclerosis and Parkinson's disease, suggesting that common deleterious disease variants are unlikely to be maintained by positive selection. There was no enrichment of Neanderthal introgression in the SNP-heritability of these disorders, suggesting that Neanderthal admixture is unlikely to have contributed to disease risk.These findings provide insight into the origins of neurodegenerative disorders within the evolution of Homo sapiens and addresses a long-standing debate, showing that Neanderthal admixture is unlikely to have contributed to common genetic risk of neurodegeneration in anatomically-modern humans.

Abstract With the advent of gene therapies for amyotrophic lateral sclerosis (ALS), there is a surge in gene testing for this disease. Although there is ample experience with gene testing for C9orf72, SOD1, FUS and TARDBP in familial ALS, large studies exploring genetic variation in all ALS-associated genes in sporadic ALS (sALS) are still scarce. Gene testing in a diagnostic setting is challenging, given the complex genetic architecture of sALS, for which there are genetic variants with large and small effect sizes. Guidelines for the interpretation of genetic variants in gene panels and for counselling of patients are lacking. We aimed to provide a thorough characterization of genetic variability in ALS genes by applying the American College of Medical Genetics and Genomics (ACMG) criteria on whole genome sequencing data from a large cohort of 6013 sporadic ALS patients and 2411 matched controls from Project MinE. We studied genetic variation in 90 ALS-associated genes and applied customized ACMG-criteria to identify pathogenic and likely pathogenic variants. Variants of unknown significance were collected as well. In addition, we determined the length of repeat expansions in C9orf72, ATXN1, ATXN2 and NIPA1 using the ExpansionHunter tool. We found C9orf72 repeat expansions in 5.21% of sALS patients. In 50 ALS-associated genes, we did not identify any pathogenic or likely pathogenic variants. In 5.89%, a pathogenic or likely pathogenic variant was found, most commonly in SOD1, TARDBP, FUS, NEK1, OPTN or TBK1. Significantly more cases carried at least one pathogenic or likely pathogenic variant compared to controls (odds ratio 1.75; P-value 1.64 × 10−5). Isolated risk factors in ATXN1, ATXN2, NIPA1 and/or UNC13A were detected in 17.33% of cases. In 71.83%, we did not find any genetic clues. A combination of variants was found in 2.88%. This study provides an inventory of pathogenic and likely pathogenic genetic variation in a large cohort of sALS patients. Overall, we identified pathogenic and likely pathogenic variants in 11.13% of ALS patients in 38 known ALS genes. In line with the oligogenic hypothesis, we found significantly more combinations of variants in cases compared to controls. Many variants of unknown significance may contribute to ALS risk, but diagnostic algorithms to reliably identify and weigh them are lacking. This work can serve as a resource for counselling and for the assembly of gene panels for ALS. Further characterization of the genetic architecture of sALS is necessary given the growing interest in gene testing in 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.

Background: Epidemiological studies that examined the association between Parkinson's disease (PD) and cancers led to inconsistent results, but they face a number of methodological difficulties. Objective: We used results from genome-wide association studies (GWASs) to study the genetic correlation between PD and different cancers to identify common genetic risk factors. Methods: We used individual data for participants of European ancestry from the Courage-PD (Comprehensive Unbiased Risk Factor Assessment for Genetics and Environment in Parkinson's Disease; PD, N = 16,519) and EPITHYR (differentiated thyroid cancer, N = 3527) consortia and summary statistics of GWASs from iPDGC (International Parkinson Disease Genomics Consortium; PD, N = 482,730), Melanoma Meta-Analysis Consortium (MMAC), Breast Cancer Association Consortium (breast cancer), the Prostate Cancer Association Group to Investigate Cancer Associated Alterations in the Genome (prostate cancer), International Lung Cancer Consortium (lung cancer), and Ovarian Cancer Association Consortium (ovarian cancer) (N comprised between 36,017 and 228,951 for cancer GWASs). We estimated the genetic correlation between PD and cancers using linkage disequilibrium score regression. We studied the association between PD and polymorphisms associated with cancers, and vice versa, using cross-phenotypes polygenic risk score (PRS) analyses. Results: We confirmed a previously reported positive genetic correlation of PD with melanoma (G(corr) = 0.16 [0.04; 0.28]) and reported an additional significant positive correlation of PD with prostate cancer (G(corr) = 0.11 [0.03; 0.19]). There was a significant inverse association between the PRS for ovarian cancer and PD (odds ratio [OR] = 0.89 [0.84; 0.94]). Conversely, the PRS of PD was positively associated with breast cancer (OR = 1.08 [1.06; 1.10]) and inversely associated with ovarian cancer (OR = 0.95 [0.91; 0.99]). The association between PD and ovarian cancer was mostly driven by rs183211 located in an intron of the NSF gene (17q21.31). Conclusions: We show evidence in favor of a contribution of pleiotropic genes to the association between PD and specific cancers. (c) 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Introduction A gastrostomy tube (GT) may be offered to people living with motor neurone disease (plwMND) to administer food, fluids and medication when eating and drinking become difficult. However, the evidence base for GT benefit is lacking. Patient decision aids (DA) support shared decision making by providing evidence-based information, elucidating personal preferences and checking understanding.1 Methods The three-phased DiAMoND study aimed to co-produce and pilot test a web-based DA to support people with MND deciding whether to have a GT. Participants included plwMND, carers and healthcare professionals (HCPs). In Phase 1, the content and design of the DA was informed by semi-structured interviews, literature reviews and prioritisation survey. In Phase 2, the prototype DA was tested with users and developed iteratively with feedback from surveys and 'think-aloud' interviews. In Phase 3 the DA was evaluated using validated questionnaires.2–5 Results In total, 16 plwMND, 16 carers and 25 HCPs took part in Phases 1 and 2. Interviews and the literature review generated a prioritisation survey with 82 content items. Seventy-seven percent (63/82) of the content of the DA was retained. A prototype DA, which conforms to international DA standards1, was produced and improved during Phase 2. In Phase 3, 17 plwMND completed questionnaires after using the DA. Most plwMND (94%) found the DA completely acceptable and would recommend it to others in their position, had no decisional conflict (88%), and were well prepared (82%) and satisfied with their decision making (100%). Conclusion Gastrostomy Tube Is it for me? was co-produced with stakeholders and found to be acceptable, practical and useful to plwMND. It is freely available from the MND Association website. The DA is a valuable tool to support plwMND and HCPs through the GT shared decision making process. References International Patient Decision Aid Standards (IPDAS) (Accessed June 23, 2022, at www.ipdas.ohri.ca.) O'Connor A. User Manual – Stage of Decision Making 2000 [updated 2003] [Available from: https://decisionaid.ohri.ca/docs/develop/user_manuals/um_stage_decision_making.pdf]. Ferron Parayre A, Labrecque M, Rousseau M, Turcotte S, Légaré F. Validation of SURE, a four-item clinical checklist for detecting decisional conflict in patients. Medical Decision Making : An International Journal Of The Society For Medical Decision Making. 2014;34(1):54–62. C Bennett, ID Graham, E Kristjansson, SA Kearing, KF Clay, O'Connor A. Validation of a preparation for decision making scale. Patient Educ Couns. 2010;78(1):130–3. Holmes-Rovner M, Kroll J, Schmitt N, Rovner DR, Breer ML, Rothert ML, et al. patient satisfaction with health care decisions:the satisfaction with decision scale. Medical Decision Making. 1996;16(1):58–64.

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.

Neurofilament levels are elevated in many neurodegenerative diseases and have shown promise as diagnostic and prognostic biomarkers in Amyotrophic Lateral Sclerosis (ALS), the most common form of Motor Neuron Disease (MND). This study assesses serum neurofilament light (NFL) and neurofilament heavy (NFH) chain concentrations in patients with ALS, other variants of motor neuron disease such as Progressive Muscular Atrophy (PMA) and Primary Lateral Sclerosis (PLS), and a range of other neurological diseases. It aims to evaluate the use of NFL and NFH to differentiate these conditions and for the prognosis of MND disease progression. NFL and NFH levels were quantified using electrochemiluminescence immunoassays (ECLIA). Both were elevated in 47 patients with MND compared to 34 patients with other neurological diseases and 33 healthy controls. NFL was able to differentiate patients with MND from the other groups with a Receiver Operating Characteristic (ROC) curve area under the curve (AUC) of 0.90 (p < 0.001). NFL correlated with the rate of disease progression in MND (rho 0.758, p < 0.001) and with the ALS Functional Rating Scale (rho −0.335, p = 0.021). NFL levels were higher in patients with ALS compared to both PMA (p = 0.032) and PLS (p = 0.012) and were able to distinguish ALS from both PMA and PLS with a ROC curve AUC of 0.767 (p = 0.005). These findings support the use of serum NFL to help diagnose and differentiate types of MND, in addition to providing prognostic information to patients and their families.