Publications by authors named "Dionne Laporte"

Purpose: People with severe mental illness (SMI) experience high levels of unemployment. We aimed to better understand the associations between clinical, social, and demographic inequality indicators and unemployment.

Methods: Data were extracted from de-identified health records of people with SMI in contact with secondary mental health services in south London, UK.

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haploinsufficiency in humans causes intellectual disability (ID). SYNGAP1 is highly expressed in cortical excitatory neurons and, reducing its expression in mice accelerates the maturation of excitatory synapses during sensitive developmental periods, restricts the critical period window for plasticity, and impairs cognition. However, its specific role in interneurons remains largely undetermined.

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  • Biallelic variants in the TBC1D24 gene are often linked to DOORS syndrome, which includes symptoms like deafness and intellectual disability.
  • This study aimed to find genetic causes in families with DOORS syndrome that lacked TBC1D24 variants through genetic sequencing methods.
  • A significant finding was the identification of a specific truncating variant in the ATP6V1B2 gene among multiple families with DOORS syndrome, suggesting a shared genetic basis and a potential connection between DOORS and another condition known as DDOD syndrome.
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"Oligogenic inheritance" is used to describe cases where more than one rare pathogenic variant is observed in the same individual. While multiple variants can alter disease presentation, the necessity of multiple variants to instigate pathogenesis has not been addressed in amyotrophic lateral sclerosis (ALS). We sequenced ALS-associated genes in C9orf72-expansion-positive and negative ALS patients, alongside unaffected controls, to test the importance of oligogenicity and variant deleteriousness in ALS.

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  • This study used machine learning to analyze genomic data of schizophrenia (SCZ) and autism spectrum disorder (ASD) to identify key genetic differences.
  • The researchers implemented gradient boosted machines on whole-exome sequencing data, leading to an 86-88% accuracy in distinguishing between SCZ and ASD cases based on genetic information.
  • The findings indicated specific gene "hubs" and biological pathways linked to each disorder, revealing both genetic similarities and distinct differences between the two conditions.
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Restless legs syndrome is a common complex disorder with different genetic and environmental risk factors. Here we used human cell lines to conduct an RNA-Seq study and observed how the gene showing the most significant association with RLS, MEIS1, acts as a regulator of the expression of many other genes. Some of the genes affected by its expression level are linked to pathways previously reported to be associated with RLS.

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Cadherins constitute a family of transmembrane proteins that mediate calcium-dependent cell-cell adhesion. The extracellular domain of cadherins consists of extracellular cadherin (EC) domains, separated by calcium binding sites. The EC interacts with other cadherin molecules in cis and in trans to mechanically hold apposing cell surfaces together.

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More than 80 known or suspected genes/loci have been reported to be involved in hereditary spastic paraplegia (HSP). Genetic and clinical overlap have been reported between HSP and other neurological condition, yet about 50% of HSP patients remain genetically undiagnosed. To identify novel genes involved in HSP, we performed a genetic analysis of 383 HSP patients from 289 families with HSP.

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  • The study focuses on the genetic background of the Nunavik Inuit, revealing that they have a unique genetic profile that is distinct from both contemporary Europeans and Native Americans.
  • It finds that the Nunavik Inuit population has experienced a small effective population size of 3,000 and a historical split from Greenlandic Inuit around 10,500 years ago.
  • The research identifies specific genomic adaptations in Nunavik Inuit related to fatty acid metabolism and links an exonic variant to a significantly increased risk of intracranial aneurysms (IAs).
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  • Autism spectrum disorder (ASD) is a complex genetic condition, with known associations primarily to a small set of genes, making it difficult to pinpoint genetic causes in many cases.
  • Researchers sequenced the whole genomes of 119 individuals with ASD to identify likely harmful genetic variants, focusing on the predicted impact and existing evidence for each variant.
  • The study discovered five new damaging variants and confirmed two novel variants in a well-known ASD gene, SCN2A, enhancing understanding of genetic factors and their link to ASD symptoms.
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  • SMPD1 gene variants, particularly p.L302P and p.fsP330, are associated with an increased risk of developing Parkinson's disease (PD) in certain populations, specifically the Ashkenazi Jewish cohort.
  • Analysis revealed that lower acid-sphingomyelinase activity in PD patients is linked to an earlier onset of the disease, indicating its potential role as a biomarker.
  • Experimental findings showed that SMPD1 mutations disrupt the normal function of acid-sphingomyelinase, leading to higher levels of α-synuclein in dopaminergic cells, which may contribute to the pathogenesis of PD.
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  • This study aimed to find rare, protein-altering genetic variants linked to restless legs syndrome (RLS) in families of French-Canadian descent.
  • Researchers analyzed whole-exome sequences from 7 families with multiple RLS-afflicted members, looking for relevant genetic variants.
  • Despite identifying 43 rare variants, none were associated with RLS in the families, suggesting that the condition might stem from noncoding regulatory variants or other unidentified genetic locations.
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  • * A whole exome sequencing study was conducted on several families with NTDs, combining new data with previously collected data to identify genetic variants linked to these defects.
  • * The study found four new loss-of-function variants in genes associated with NTD and highlighted a potential new candidate gene, MYO1E, suggesting advancements in understanding the genetic causes of NTD through next-generation sequencing.
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Background: Hereditary spastic paraplegia (HSP) is a group of rare disorders characterized by spastic paraparesis and other symptoms. Often, other diseases can mimic HSP, which may delay diagnosis and treatment.

Methods: Whole exome sequencing was performed in families with clinically suspected HSP without a genetic diagnosis.

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Childhood-onset schizophrenia (COS) is a rare and severe form of schizophrenia, defined as having an onset before the age of 13. The male COS cases have a slightly younger age of onset than female cases. They also present with a higher rate of comorbid developmental disorders.

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  • Non-invasive prenatal aneuploidy testing (NIPT) uses next-generation sequencing to analyze fetal DNA in maternal blood, focusing on chromosomal ratios to detect abnormalities.
  • The study examines how the fraction of fetal DNA (FF) in maternal plasma affects the test's specificity and positive predictive values (PPV), utilizing both theoretical models and data from three NIPT assays for validation.
  • Findings indicate that small changes in FF and the variability in chromosomal measurements significantly influence test accuracy, highlighting the need for precise FF and measurement variability data for reliable NIPT results.
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Childhood-onset schizophrenia (COS) is a rare and severe form of schizophrenia defined as onset before age of 13. Here we report on two unrelated cases diagnosed with both COS and alternating hemiplegia of childhood (AHC), and for whom two distinct pathogenic de novo variants were identified in the ATP1A3 gene. ATP1A3 encodes the α-subunit of a neuron-specific ATP-dependent transmembrane sodium-potassium pump.

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Brain arteriovenous malformations (AVMs) are abnormal connections between arteries and veins that can result in hemorrhagic stroke. A genetic basis for AVMs is suspected, and we investigated potential mutations in a 14-year-old girl who developed a recurrent brain AVM. Whole-exome sequencing (WES) of AVM lesion tissue and blood was performed accompanied by modeling, protein expression observation in lesion tissue and zebrafish modeling.

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  • The original article included a mistake in the author's name.
  • Bouchra Ouled Amar Bencheikh was misrepresented as Bouchra Oulad Amar Bencheikh.
  • This correction was highlighted after the article was published.
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Epilepsy will affect nearly 3% of people at some point during their lifetime. Previous copy number variants (CNVs) studies of epilepsy have used array-based technology and were restricted to the detection of large or exonic events. In contrast, whole-genome sequencing (WGS) has the potential to more comprehensively profile CNVs but existing analytic methods suffer from limited accuracy.

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  • Intracranial Aneurysm (IA) is prevalent worldwide, affecting 1-3% of the population, with a notably higher incidence in the French-Canadian population due to a founder effect and a familial pattern of occurrence.
  • The study genotyped a cohort of 257 familial IA patients alongside 1,992 controls, identifying a significant locus at 3p14.2 (FHIT) linked to IA, confirmed through further testing in Inuit families and additional cohorts.
  • Two new potential IA loci were identified in the French-Canadian population: FHIT, related to hypertensive IA, and CCDC80, suggesting genetic relevance to IA development, alongside the confirmation of an existing locus at 18q11
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Background: Epilepsy regroups a common and diverse set of chronic neurological disorders that are characterized by spontaneous, unprovoked, and recurrent epileptic seizures. Epilepsies have a highly heterogeneous background with a strong genetic contribution and various mode of inheritance. X-linked epilepsy usually manifests as part of a syndrome or epileptic encephalopathy.

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RAD51D is a key player in DNA repair by homologous recombination (HR), and truncating variant carriers have an increased risk for ovarian cancer. However, the contribution of nontruncating variants to cancer predisposition remains uncertain. Using deep sequencing and case-control genotyping studies, we show that in French Canadians, the missense variant c.

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Neural tube defects, including spina bifida, are among the most common birth defects caused by failure of neural tube closure during development. They have a complex etiology involving largely undetermined environmental and genetic factors. Previous studies in mouse models have implicated the transcription factor Grhl3 as an important factor in the pathogenesis of spina bifida.

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