Publications by authors named "Guy Rouleau"

Biallelic variants in GLDN have recently been associated with lethal congenital contracture syndrome 11 (LCCS11), a form of fetal akinesia deformation sequence (FADS) with high neonatal mortality. In this report, we describe five individuals from two Canadian Inuit families originating from different communities in Nunavik all affected with FADS and harboring a rare homozygous missense variant, [NM_181789.4:c.

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The hyper-unstable Chr9p21 locus, harbouring the interferon gene cluster, oncogenes and , is linked to multiple diseases. (GGGGCC)n expansions (Exp) are associated with incompletely penetrant amyotrophic lateral sclerosis, frontotemporal dementia and autoimmune disorders. Exp patients display hyperactive cGAS-STING-linked interferon immune and DNA damage responses, but the source of immunostimulatory or damaged DNA is unknown.

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This study focuses on the modulatory effects of gold nanoclusters with 25 gold atoms and 18 acetyl cysteines (AuAcCys) in human microglia, human iPSC-derived neurons and SH-SY5Y differentiated human neuronal cells. The combination of chemical, biological, and computational methods shows the well-retained viability of these human cells treated with AuAcCys, interactions between AuAcCys and transcription factor TFEB (computational approach), interactions between TFEB and HMGB1 (proximity ligation assay and molecular modeling using AlphaFold), modulation of the abundance and location of acHMGB1 by AuAcCys (immunocytochemistry), and the reduction of ROS in cells treated with AuAcCys (CellROX live imaging). These novel findings in human neural cells, particularly neurons, encourage further studies in experimental animal models of neurological disorders and/or human organoids to exploit the unique structural and photophysical properties of gold nanoclusters and to better understand their ability to modulate molecular mechanisms in human cells.

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The hyper-unstable Chr9p21 locus, harbouring the interferon gene cluster, oncogenes and is linked to multiple diseases. (GGGGCC)n expansions ( Exp) are associated with incompletely penetrant amyotrophic lateral sclerosis, frontotemporal dementia and autoimmune disorders. Exp patients display hyperactive cGAS-STING-linked interferon immune and DNA damage responses, but the source of immuno-stimulatory or damaged DNA is unknown.

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Background: The findings of variants of uncertain significance (VUS) on a clinical genetic testing report pose a challenge for attending healthcare professionals (HCPs) in patient care. Here, we describe the outcomes of multidisciplinary VUS Rounds, implemented at a neurological disease tertiary care centre, which aid in interpreting and communicating VUS identified in our neurogenetics patient population.

Methods: VUS Rounds brought together genetic counsellors, molecular geneticists and scientists to evaluate VUS against genomic and phenotypic evidence and assign an internal temperature classification of 'VUS Hot', 'True VUS' or 'VUS Cold', corresponding to potential pathogenicity.

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Although the first signs of autism are often observed as early as 18-36 months of age, there is a broad uncertainty regarding future development, and clinicians lack predictive tools to identify those who will later be diagnosed with co-occurring intellectual disability (ID). Here, we developed predictive models of ID in autistic children (n=5,633 from three cohorts), integrating different classes of genetic variants alongside developmental milestones. The integrated model yielded an AUC ROC=0.

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Reactive changes of glial cells during neuroinflammation impact brain disorders and disease progression. Elucidating the mechanisms that control reactive gliosis may help us to understand brain pathophysiology and improve outcomes. Here, we report that adult ablation of autism spectrum disorder (ASD)-associated CHD8 in astrocytes attenuates reactive gliosis via remodeling chromatin accessibility, changing gene expression.

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Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the progressive death of motor neurons (MNs). Glial cells play roles in MN degeneration in ALS. More specifically, astrocytes with mutations in the ALS-associated gene Cu/Zn superoxide dismutase 1 (SOD1) promote MN death.

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Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative spinocerebellar ataxia caused by a polyglutamine-coding CAG repeat expansion in the ATXN3 gene. While the CAG length correlates negatively with the age at onset, it accounts for approximately 50% of its variability only. Despite larger efforts in identifying contributing genetic factors, candidate genes with a robust and plausible impact on the molecular pathogenesis of MJD are scarce.

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Article Synopsis
  • Restless legs syndrome (RLS) is a neurological disorder characterized by uncomfortable leg sensations and an urge to move, especially during rest, but its genetic causes are not fully known.
  • Researchers conducted a large-scale study analyzing the genomes of nearly 10,000 RLS cases and over 38,000 controls, discovering 9 genetic risk loci, including one novel locus (LMX1B).
  • The findings suggest significant genetic overlaps between RLS and other conditions like neuroticism, depression, and even intelligence, advancing the understanding of RLS's genetic determinants.
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Although large-scale genetic association studies have proven useful for the delineation of neurodegenerative disease processes, we still lack a full understanding of the pathological mechanisms of these diseases, resulting in few appropriate treatment options and diagnostic challenges. To mitigate these gaps, the Neurodegenerative Disease Knowledge Portal (NDKP) was created as an open-science initiative with the aim to aggregate, enable analysis, and display all available genomic datasets of neurodegenerative disease, while protecting the integrity and confidentiality of the underlying datasets. The portal contains 218 genomic datasets, including genotyping and sequencing studies, of individuals across ten different phenotypic groups, including neurological conditions such as Alzheimer's disease, amyotrophic lateral sclerosis, Lewy body dementia, and Parkinson's disease.

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Article Synopsis
  • Restless legs syndrome (RLS) affects nearly 10% of older adults, but many face delays in diagnosis and treatment.
  • A large-scale genetic study identified 164 risk loci for RLS, enhancing our understanding of its genetic basis and showing similarities in genetic predispositions between sexes.
  • Findings suggest potential drug targets, a relationship between RLS and diabetes, and highlight the effectiveness of machine learning in predicting RLS risk using genetic and other data.
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Background: Bipolar disorder (BD) is a multifactorial psychiatric illness affecting ∼1% of the global adult population. Lithium (Li), is the most effective mood stabilizer for BD but works only for a subset of patients and its mechanism of action remains largely elusive.

Methods: In the present study, we used iPSC-derived neurons from patients with BD who are responsive (LR) or not (LNR) to lithium.

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Introduction: Rare copy number variants (CNVs) and polygenic risk for intelligence (PRS-IQ) both confer susceptibility for autism spectrum disorder (ASD) but have opposing effects on cognitive ability. The field has struggled to disentangle the effects of these two classes of genomic variants on cognitive ability from their effects on ASD susceptibility, in part because previous studies did not include controls with cognitive measures. We aim to investigate the impact of these genomic variants on ASD risk while adjusting for their known effects on cognitive ability.

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Sleep disorders affect millions of people around the world and have a high comorbidity with psychiatric disorders. While current hypnotics mostly increase non-rapid eye movement sleep (NREMS), drugs acting selectively on enhancing rapid eye movement sleep (REMS) are lacking. This polysomnographic study in male rats showed that the first-in-class selective melatonin MT receptor partial agonist UCM871 increases the duration of REMS without affecting that of NREMS.

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Background: To examine the association between race, ethnicity, and parental educational attainment on tic-related outcomes among Tourette Syndrome (TS) participants in the Tourette Association of America International Consortium for Genetics (TAAICG) database.

Methods: 723 participants in the TAAICG dataset aged ≤21 years were included. The relationships between tic-related outcomes and race and ethnicity were examined using linear and logistic regressions.

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Article Synopsis
  • Lithium is the primary treatment for bipolar disorder (BD), but how it works and predicts outcomes is not fully understood.
  • A previous study identified key cellular pathways linked to lithium response, including focal adhesion and PI3K-Akt signaling.
  • In this new study, researchers confirmed these pathways in a larger group of 2039 patients but found no connection with the extracellular matrix, suggesting that issues with neuronal growth signaling may impact lithium effectiveness.
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Background: Congenital mirror movements (CMM) is a rare neurodevelopmental disorder characterized by involuntary movements from one side of the body that mirror voluntary movements on the opposite side. To date, five genes have been associated with CMM, namely DCC, RAD51, NTN1, ARHGEF7, and DNAL4.

Objective: The aim of this study is to characterize the genetic landscape of CMM in a large group of 80 affected individuals.

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Background And Objective: Tourette Syndrome (TS) and Persistent Motor or Vocal Tic Disorders (PMVT) are more prevalent in males (vs. females). Females with TS may have a delay in diagnosis, and more complex tic features (vs.

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Article Synopsis
  • Restless legs syndrome (RLS) is a neurological condition characterized by uncomfortable leg sensations and an urge to move, especially during rest; the causes are not fully understood.
  • A study involving genome sequencing of nearly 10,000 RLS cases and almost 39,000 controls identified nine genetic risk loci, including one new locus, which contributes to understanding the genetics behind RLS.
  • The research also found correlations between RLS and other conditions like neuroticism, depression, and intelligence, suggesting that common genetic variants play a significant role in this widespread disorder.
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