Publications by authors named "Yves Dion"

Tourette syndrome (TS) is a neuropsychiatric disorder of complex genetic architecture involving multiple interacting genes. Here, we sought to elucidate the pathways that underlie the neurobiology of the disorder through genome-wide analysis. We analyzed genome-wide genotypic data of 3581 individuals with TS and 7682 ancestry-matched controls and investigated associations of TS with sets of genes that are expressed in particular cell types and operate in specific neuronal and glial functions.

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Article Synopsis
  • The study investigates the genetic basis of Tourette's syndrome through a genome-wide association study (GWAS) involving a large sample of case subjects and controls to identify shared genetic factors and predict tic severity.
  • A significant genetic association was found with the FLT3 gene on chromosome 13, but it was not confirmed in a follow-up study; nonetheless, most of the heritability was linked to genetic variants in conserved regions.
  • The findings suggest that genetic risk scores for Tourette's are linked to the severity of tics and are higher in individuals with a family history of tic disorders, indicating a potential genetic influence on the manifestation of the syndrome.
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Triticale (x Wittmack) is an important feed crop which suffers severe yield, grade and end-use quality losses due to head blight (FHB). Development of resistant triticale cultivars is hindered by lack of effective genetic resistance sources. To dissect FHB resistance, a doubled haploid spring triticale population produced from the cross TMP16315/AC Ultima using a microspore culture method, was phenotyped for FHB incidence, severity, visual rating index (VRI), deoxynivalenol (DON) and some associated traits (ergot, grain protein content, test weight, yield, plant height and lodging) followed by single nucleotide polymorphism (SNP) genotyping.

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Trichotillomania/hair pulling disorder (HPD) and excoriation/skin picking disorder (SPD) are childhood-onset, body-focused repetitive behaviors that are thought to share genetic susceptibility and underlying pathophysiology with obsessive-compulsive disorder (OCD) and Tourette syndrome (TS). We sought to determine the prevalence of DSM-5 HPD and SPD in TS patients, and to identify clinical factors most associated with their co-morbidity with TS. Participants included 811 TS patients recruited from TS specialty clinics for a multi-center genetic study.

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Objective: Tourette's disorder (TD) and autism spectrum disorder (ASD) share clinical features and possibly an overlapping etiology. The aims of this study were to examine ASD symptom rates in participants with TD, and to characterize the relationships between ASD symptom patterns and TD, obsessive-compulsive disorder (OCD), and attention-deficit/hyperactivity disorder (ADHD).

Method: Participants with TD (n = 535) and their family members (n =234) recruited for genetic studies reported TD, OCD, and ADHD symptoms and completed the Social Responsiveness Scale Second Edition (SRS), which was used to characterize ASD symptoms.

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Tourette syndrome (TS) is a model neuropsychiatric disorder thought to arise from abnormal development and/or maintenance of cortico-striato-thalamo-cortical circuits. TS is highly heritable, but its underlying genetic causes are still elusive, and no genome-wide significant loci have been discovered to date. We analyzed a European ancestry sample of 2,434 TS cases and 4,093 ancestry-matched controls for rare (< 1% frequency) copy-number variants (CNVs) using SNP microarray data.

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Objective: Phenotypic heterogeneity in Tourette syndrome is partly due to complex genetic relationships among Tourette syndrome, obsessive-compulsive disorder (OCD), and attention deficit hyperactivity disorder (ADHD). Identifying symptom-based endophenotypes across diagnoses may aid gene-finding efforts.

Method: Assessments for Tourette syndrome, OCD, and ADHD symptoms were conducted in a discovery sample of 3,494 individuals recruited for genetic studies.

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Objective: To identify heritable symptom-based subtypes of Tourette syndrome (TS).

Methods: Forty-nine motor and phonic tics were examined in 3,494 individuals (1,191 TS probands and 2,303 first-degree relatives). Item-level exploratory factor and latent class analyses (LCA) were used to identify tic-based subtypes.

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Fusarium head blight (FHB), caused by Fusarium graminearum, is one of the most devastating diseases of wheat and barley. Resistance to FHB is highly complex and quantitative in nature, and is most often classified as resistance to spikelet infection and resistance to spread of pathogen through the rachis. In the present study, a resistant (CI9831) and a susceptible (H106-371) two-row barley genotypes, with contrasting levels of spikelet resistance to FHB, pathogen or mock-inoculated, were profiled for metabolites based on liquid chromatography and high resolution mass spectrometry.

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Importance: Tourette syndrome (TS) is characterized by high rates of psychiatric comorbidity; however, few studies have fully characterized these comorbidities. Furthermore, most studies have included relatively few participants (<200), and none has examined the ages of highest risk for each TS-associated comorbidity or their etiologic relationship to TS.

Objective: To characterize the lifetime prevalence, clinical associations, ages of highest risk, and etiology of psychiatric comorbidity among individuals with TS.

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Objective: Obsessive-compulsive disorder (OCD) and Tourette's syndrome are highly heritable neurodevelopmental disorders that are thought to share genetic risk factors. However, the identification of definitive susceptibility genes for these etiologically complex disorders remains elusive. The authors report a combined genome-wide association study (GWAS) of Tourette's syndrome and OCD.

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Objective: Obsessive-compulsive disorder (OCD) and Tourette syndrome (TS) are heritable neurodevelopmental disorders with a partially shared genetic etiology. This study represents the first genome-wide investigation of large (>500 kb), rare (<1%) copy number variants (CNVs) in OCD and the largest genome-wide CNV analysis in TS to date.

Method: The primary analyses used a cross-disorder design for 2,699 case patients (1,613 ascertained for OCD, 1,086 ascertained for TS) and 1,789 controls.

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The direct estimation of heritability from genome-wide common variant data as implemented in the program Genome-wide Complex Trait Analysis (GCTA) has provided a means to quantify heritability attributable to all interrogated variants. We have quantified the variance in liability to disease explained by all SNPs for two phenotypically-related neurobehavioral disorders, obsessive-compulsive disorder (OCD) and Tourette Syndrome (TS), using GCTA. Our analysis yielded a heritability point estimate of 0.

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Article Synopsis
  • This clinical guideline focuses on nonpharmacological treatments for tic disorders, highlighting strong recommendations for habit reversal therapy and exposure and response prevention, ideally combined with a supportive psychoeducational program and pharmacotherapy.
  • Although deep brain stimulation (DBS) shows some efficacy for severe tics, its evidence quality is low, and it should only be considered experimental, performed by experts within research settings.
  • Transcranial magnetic stimulation (TMS) lacks supportive evidence for treating tics but may be safe for further study.
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This article seeks to provide the practising clinician with guidance on the pharmacological management of tic disorders in children and adults. We performed a systematic review of the literature on the treatment of tic disorders. A multi-institutional group of 14 experts in psychiatry, child psychiatry, neurology, pediatrics, and psychology engaged in a consensus meeting.

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Fusarium head blight (FHB) is a serious disease in the wet conditions of eastern Canada. Tillage practices and herbicide applications have been reported to influence disease intensity. This study aimed to determine the effect of glyphosate on FHB development in wheat and barley and on Fusarium graminearum inoculum production under different soil tillages.

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Fusarium head blight (FHB) is an economically important disease of the family Triticeae, as, apart from yield reduction it also causes quality deterioration by producing mycotoxins. Host resistance is the most promising way to control the disease. Metabolic profiling was applied to identify resistance related (RR) metabolites against Fusarium graminearum in five FHB-resistant genotypes ('Chevron', 'H5277-44', 'H5277-164', 'M92-513' and 'M122') relative to one FHB-susceptible genotype ('Stander').

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Article Synopsis
  • Resistance to fusarium head blight (FHB) in barley is inherited quantitatively, and a study used metabolomics to identify biomarkers for this resistance.
  • Five FHB-resistant barley genotypes and one susceptible genotype were inoculated to assess disease severity and analyze metabolites, leading to the identification of significant treatment peaks.
  • Key metabolites indicative of resistance included phenylalanine, p-coumaric acid, and jasmonate, with specific findings on toxin levels and detoxification processes suggesting potential biomarkers for enhancing FHB resistance.
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Article Synopsis
  • More than 100 resistance quantitative trait loci (QTLs) have been found in wheat and barley that contribute to resistance against Fusarium head blight (FHB), indicating multiple mechanisms of resistance.
  • The study focused on using metabolomics to identify specific metabolites in barley genotypes that correlate with FHB resistance, comparing the resistant Chevron genotype with the more susceptible Stander.
  • A significant number of resistance-related metabolites were identified, primarily from phenylpropanoid, flavonoid, fatty acid, and terpenoid pathways, suggesting their potential use as biomarkers in resistance screening and for further understanding of related genetic functions.
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Objective: To test the association between Tourette syndrome (TS) and genetic variants in genomic loci MEIS1, MAP2K5/LBXCOR1, and BTBD9, for which genome-wide association studies in restless legs syndrome and periodic limb movements during sleep revealed common risk variants.

Design: Case-control association study.

Setting: Movement disorder clinic in Montreal.

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Previous studies have found association and linkage between Tourette syndrome (TS) and markers at the 11q24 region, mainly with markers D11S1377 and D11S933. In order to determine if these positive findings could be replicated in our sample, we undertook a family-based association study in 199 French Canadian TS nuclear families. We genotyped 572 individuals from 174 complete and 25 incomplete TS trios.

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Vascular surgery is evolving, as other specialities, toward minimally invasive techniques. Presently, 3 approaches to aortoiliac disease are suggested as minimally invasive. Besides the endovascular procedures, laparoscopic techniques and minilaparotomy are being advocated.

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Tourette syndrome (TS) is a complex neuropychiatric disorder with a strong genetic basis. Although no specific susceptibility genes have been identified for TS, cytogenetic studies in selected cases suggest the existence of a predisposing gene located in the 7q31 chromosomal region. In order to test the hypothesis of a possible relationship between this region and TS at the population level, we undertook a family based association study in a sample of French Canadian patients from Quebec.

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Background: Depression is a common comorbid condition in patients with Tourette's disorder. While risperidone is not usually known to induce dysphoria or depression in patients treated for other psychiatric disorders, previous short-term 4- to 12-week trials of risperidone for Tourette's disorder have reported a 2.6% to 30.

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