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1.
Adapt Phys Activ Q ; 37(1): 72-89, 2020 01 01.
Article in English | MEDLINE | ID: mdl-31877560

ABSTRACT

The purpose of this study was to understand the learning experiences and acquisition of knowledge of youth parasport coaches. Five able-bodied male participants (M = 39 years old), who coached youth with a physical disability for an average of 7.4 years, participated in individual interviews. An inductive thematic analysis identified patterns within and across the data, allowing for description and interpretation of the meaning and importance of the themes. The results showed that coaches learned mostly from informal experiences, particularly through mentoring, trial and error, or use of technology. In addition, these learning opportunities were influenced by personal, environmental, and social factors. These findings can help to guide current and future generations of coaches of youth participants with a physical disability by highlighting available resources and addressing several barriers and facilitators to their learning.


Subject(s)
Disabled Persons , Learning , Mentoring , Physical Education and Training , Sports , Adolescent , Humans , Male , Mentors , Qualitative Research
2.
Nature ; 482(7384): 226-31, 2012 Jan 29.
Article in English | MEDLINE | ID: mdl-22286061

ABSTRACT

Glioblastoma multiforme (GBM) is a lethal brain tumour in adults and children. However, DNA copy number and gene expression signatures indicate differences between adult and paediatric cases. To explore the genetic events underlying this distinction, we sequenced the exomes of 48 paediatric GBM samples. Somatic mutations in the H3.3-ATRX-DAXX chromatin remodelling pathway were identified in 44% of tumours (21/48). Recurrent mutations in H3F3A, which encodes the replication-independent histone 3 variant H3.3, were observed in 31% of tumours, and led to amino acid substitutions at two critical positions within the histone tail (K27M, G34R/G34V) involved in key regulatory post-translational modifications. Mutations in ATRX (α-thalassaemia/mental retardation syndrome X-linked) and DAXX (death-domain associated protein), encoding two subunits of a chromatin remodelling complex required for H3.3 incorporation at pericentric heterochromatin and telomeres, were identified in 31% of samples overall, and in 100% of tumours harbouring a G34R or G34V H3.3 mutation. Somatic TP53 mutations were identified in 54% of all cases, and in 86% of samples with H3F3A and/or ATRX mutations. Screening of a large cohort of gliomas of various grades and histologies (n = 784) showed H3F3A mutations to be specific to GBM and highly prevalent in children and young adults. Furthermore, the presence of H3F3A/ATRX-DAXX/TP53 mutations was strongly associated with alternative lengthening of telomeres and specific gene expression profiles. This is, to our knowledge, the first report to highlight recurrent mutations in a regulatory histone in humans, and our data suggest that defects of the chromatin architecture underlie paediatric and young adult GBM pathogenesis.


Subject(s)
Chromatin Assembly and Disassembly/genetics , Chromatin/genetics , Glioblastoma/genetics , Histones/genetics , Mutation/genetics , Adaptor Proteins, Signal Transducing/genetics , Base Sequence , Child , Chromatin/metabolism , Co-Repressor Proteins , DNA Helicases/genetics , DNA Mutational Analysis , Exome/genetics , Gene Expression Profiling , Histones/metabolism , Humans , Molecular Chaperones , Molecular Sequence Data , Nuclear Proteins/genetics , Telomere/genetics , Tumor Suppressor Protein p53/genetics , X-linked Nuclear Protein
3.
BMC Genomics ; 18(1): 96, 2017 01 18.
Article in English | MEDLINE | ID: mdl-28100169

ABSTRACT

BACKGROUND: Epigenetic modifications of DNA, such as 5-methylcytosine and 5-hydroxymethycytosine, play important roles in development and disease. Here, we present a cost-effective and versatile methodology for the analysis of DNA methylation in targeted genomic regions, which comprises multiplexed, PCR-based preparation of bisulfite DNA libraries followed by customized MiSeq sequencing. RESULTS: Using bisulfite and oxidative bisulfite conversion of DNA, we have performed multiplexed targeted sequencing to analyse several kilobases of genomic DNA in up to 478 samples, and achieved high coverage data of 5-methylcytosine and 5-hydroxymethycytosine at single-base resolution. Our results demonstrate the ability of this methodology to detect all levels of cytosine modifications at greater than 100× coverage in large sample sets at low cost compared to other targeted methods. CONCLUSIONS: This approach can be applied to multiple settings, from candidate gene to clinical studies, and is especially useful for validation of differentially methylated or hydroxymethylated regions following whole-genome analyses.


Subject(s)
5-Methylcytosine/analogs & derivatives , 5-Methylcytosine/metabolism , Sequence Analysis, DNA/methods , Sulfites/pharmacology , Adult , DNA Methylation/drug effects , Humans , Male , Oxidation-Reduction
4.
Nat Genet ; 38(1): 93-100, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16311595

ABSTRACT

Methylmalonic aciduria and homocystinuria, cblC type (OMIM 277400), is the most common inborn error of vitamin B(12) (cobalamin) metabolism, with about 250 known cases. Affected individuals have developmental, hematological, neurological, metabolic, ophthalmologic and dermatologic clinical findings. Although considered a disease of infancy or childhood, some individuals develop symptoms in adulthood. The cblC locus was mapped to chromosome region 1p by linkage analysis. We refined the chromosomal interval using homozygosity mapping and haplotype analyses and identified the MMACHC gene. In 204 individuals, 42 different mutations were identified, many consistent with a loss of function of the protein product. One mutation, 271dupA, accounted for 40% of all disease alleles. Transduction of wild-type MMACHC into immortalized cblC fibroblast cell lines corrected the cellular phenotype. Molecular modeling predicts that the C-terminal region of the gene product folds similarly to TonB, a bacterial protein involved in energy transduction for cobalamin uptake.


Subject(s)
Carrier Proteins/genetics , Homocystinuria/genetics , Metabolism, Inborn Errors/genetics , Methylmalonic Acid/urine , Mutation , Amino Acid Sequence , Bacterial Proteins/chemistry , Carrier Proteins/chemistry , Carrier Proteins/metabolism , Cell Line , Chromosome Mapping , Conserved Sequence , Fibroblasts/metabolism , Haplotypes/genetics , Humans , Membrane Proteins/chemistry , Molecular Sequence Data , Oxidoreductases , Protein Folding , Structural Homology, Protein , Vitamin B 12/metabolism
5.
Acta Neuropathol ; 128(1): 111-22, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24839956

ABSTRACT

Individuals harboring germ-line DICER1 mutations are predisposed to a rare cancer syndrome, the DICER1 Syndrome or pleuropulmonary blastoma-familial tumor and dysplasia syndrome [online Mendelian inheritance in man (OMIM) #601200]. In addition, specific somatic mutations in the DICER1 RNase III catalytic domain have been identified in several DICER1-associated tumor types. Pituitary blastoma (PitB) was identified as a distinct entity in 2008, and is a very rare, potentially lethal early childhood tumor of the pituitary gland. Since the discovery by our team of an inherited mutation in DICER1 in a child with PitB in 2011, we have identified 12 additional PitB cases. We aimed to determine the contribution of germ-line and somatic DICER1 mutations to PitB. We hypothesized that PitB is a pathognomonic feature of a germ-line DICER1 mutation and that each PitB will harbor a second somatic mutation in DICER1. Lymphocyte or saliva DNA samples ascertained from ten infants with PitB were screened and nine were found to harbor a heterozygous germ-line DICER1 mutation. We identified additional DICER1 mutations in nine of ten tested PitB tumor samples, eight of which were confirmed to be somatic in origin. Seven of these mutations occurred within the RNase IIIb catalytic domain, a domain essential to the generation of 5p miRNAs from the 5' arm of miRNA-precursors. Germ-line DICER1 mutations are a major contributor to PitB. Second somatic DICER1 "hits" occurring within the RNase IIIb domain also appear to be critical in PitB pathogenesis.


Subject(s)
DEAD-box RNA Helicases/genetics , Mutation , Neoplasms, Complex and Mixed/genetics , Neoplasms, Complex and Mixed/pathology , Pituitary Neoplasms/genetics , Pituitary Neoplasms/pathology , Ribonuclease III/genetics , Child, Preschool , DNA Mutational Analysis , Fatal Outcome , Germ-Line Mutation , Humans , Immunohistochemistry , Infant , Magnetic Resonance Imaging , Neoplasms, Complex and Mixed/surgery , Pedigree , Pituitary Neoplasms/surgery , Radiography, Thoracic , Tomography, X-Ray Computed , Treatment Outcome
6.
Rehabil Psychol ; 2024 Jan 25.
Article in English | MEDLINE | ID: mdl-38271017

ABSTRACT

PURPOSE: Research has examined peer mentorship to understand how it may help people with spinal cord injury (SCI) adapt and thrive. We still lack an in-depth understanding of the perspectives of SCI peer mentors and mentees on their dyadic relationship. This study was to explore the dyadic interactions and relationships between SCI peer mentors and mentees in a peer mentorship program delivered at a rehabilitation center. RESEARCH METHOD: Between 2016 and 2017, we recruited two dyads of peer mentor and mentee with SCI (N = 4). Each participant completed three one-on-one interviews (N = 12). Data were analyzed using a creative nonfiction approach. RESULTS: Three unique dialogical stories were developed. Story 1 (A slow and steady start) described how mentors took a mentee-centered approach in building the relationship. Story 2 (Mentorship and friendship: negotiating the "grey zone") highlighted how mentees and mentors experienced challenges in navigating the boundaries between mentorship and friendship. Story 3 (The "endless" job for mentor) showcased how the relationship could enter a phase in which it could affect mentors' well-being. CONCLUSIONS: The stories highlighted important attributes to the relationships between SCI mentors and mentees. Considerations were suggested for community-based SCI organizations to integrate peer mentorship into rehabilitation settings, including optimizing mentorship introductions and matching, defining mentors' role explicitly, and building support systems for mentors. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

7.
NPJ Genom Med ; 9(1): 8, 2024 Feb 07.
Article in English | MEDLINE | ID: mdl-38326393

ABSTRACT

Whole genome sequencing (WGS) at high-depth (30X) allows the accurate discovery of variants in the coding and non-coding DNA regions and helps elucidate the genetic underpinnings of human health and diseases. Yet, due to the prohibitive cost of high-depth WGS, most large-scale genetic association studies use genotyping arrays or high-depth whole exome sequencing (WES). Here we propose a cost-effective method which we call "Whole Exome Genome Sequencing" (WEGS), that combines low-depth WGS and high-depth WES with up to 8 samples pooled and sequenced simultaneously (multiplexed). We experimentally assess the performance of WEGS with four different depth of coverage and sample multiplexing configurations. We show that the optimal WEGS configurations are 1.7-2.0 times cheaper than standard WES (no-plexing), 1.8-2.1 times cheaper than high-depth WGS, reach similar recall and precision rates in detecting coding variants as WES, and capture more population-specific variants in the rest of the genome that are difficult to recover when using genotype imputation methods. We apply WEGS to 862 patients with peripheral artery disease and show that it directly assesses more known disease-associated variants than a typical genotyping array and thousands of non-imputable variants per disease-associated locus.

8.
Acta Neuropathol ; 125(5): 659-69, 2013 May.
Article in English | MEDLINE | ID: mdl-23417712

ABSTRACT

Recurrent mutations affecting the histone H3.3 residues Lys27 or indirectly Lys36 are frequent drivers of pediatric high-grade gliomas (over 30% of HGGs). To identify additional driver mutations in HGGs, we investigated a cohort of 60 pediatric HGGs using whole-exome sequencing (WES) and compared them to 543 exomes from non-cancer control samples. We identified mutations in SETD2, a H3K36 trimethyltransferase, in 15% of pediatric HGGs, a result that was genome-wide significant (FDR = 0.029). Most SETD2 alterations were truncating mutations. Sequencing the gene in this cohort and another validation cohort (123 gliomas from all ages and grades) showed SETD2 mutations to be specific to high-grade tumors affecting 15% of pediatric HGGs (11/73) and 8% of adult HGGs (5/65) while no SETD2 mutations were identified in low-grade diffuse gliomas (0/45). Furthermore, SETD2 mutations were mutually exclusive with H3F3A mutations in HGGs (P = 0.0492) while they partly overlapped with IDH1 mutations (4/14), and SETD2-mutant tumors were found exclusively in the cerebral hemispheres (P = 0.0055). SETD2 is the only H3K36 trimethyltransferase in humans, and SETD2-mutant tumors showed a substantial decrease in H3K36me3 levels (P < 0.001), indicating that the mutations are loss-of-function. These data suggest that loss-of-function SETD2 mutations occur in older children and young adults and are specific to HGG of the cerebral cortex, similar to the H3.3 G34R/V and IDH mutations. Taken together, our results suggest that mutations disrupting the histone code at H3K36, including H3.3 G34R/V, IDH1 and/or SETD2 mutations, are central to the genesis of hemispheric HGGs in older children and young adults.


Subject(s)
Brain Neoplasms/genetics , Glioma/genetics , Histone-Lysine N-Methyltransferase/genetics , Histone-Lysine N-Methyltransferase/metabolism , Histones/metabolism , Mutation/genetics , Adolescent , Adult , Age Factors , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Case-Control Studies , Child , Cohort Studies , Exome , Glioma/metabolism , Glioma/pathology , Histone Methyltransferases , Humans , Infant , Methylation , Middle Aged , Neoplasm Grading , Young Adult
9.
Transl Behav Med ; 13(7): 486-500, 2023 07 01.
Article in English | MEDLINE | ID: mdl-36999796

ABSTRACT

Community-based physical activity opportunities have been shown to help adults with physical disabilities improve their participation in daily activities and reduce social isolation. Despite the known benefits, substantial barriers and challenges inhibit accessibility to these physical activity opportunities. To facilitate the co-construction of strategies to overcome accessibility issues pertaining to community-based physical activity opportunities. In total, 45 individuals with physical disabilities, patients at a rehabilitation hospital, staff members of disability organizations, staff of local or provincial government agencies/departments, kinesiologists, occupational therapists, graduate students, and peer mentors participated in one of four World Cafés held in their respective cities. World Café is a methodology for fostering collaborative, solution-focused conversation that aims to solve problems through collective intelligence. Participants were divided into groups of three to four people and invited to engage in evolving rounds of discussions responding to prompts about accessibility to physical activity in their communities. Transcripts were analyzed using content analysis. In total, 17 strategies were identified, addressing 5 areas: representation and visibility (e.g., prioritize hiring people with a disability), finances (e.g., reduce direct costs for participants), connection and social support (e.g., foster social networks that provide informational support), education and programming (e.g., enhance awareness of existing services and resources), and government programs and policies (e.g., enforce accessibility standards for indoor and outdoor spaces). The findings of this study provide strategies and practical applications for community programs and governments to consider for increasing access to physical activity opportunities for people with physical disabilities.


Adults living with physical disabilities experience numerous benefits (e.g., greater social connection and ability to complete everyday tasks) from participation in community-based physical activities. Despite the known benefits of physical activity for adults with physical disabilities, accessibility to community-based physical activity opportunities remain limited in Canada. The purpose of this study was to facilitate conversations among members of the disability and physical activity communities and co-develop strategies to improve access to community-based physical activity opportunities. In total, 45 participants in 3 Canadian cities were divided into small groups to engage in evolving rounds of discussions responding to access to physical activity in their communities. Altogether, 17 strategies targeting 5 areas related to accessibility were developed. The five areas included representation and visibility (e.g., prioritize hiring people with a disability), finances (e.g., reduce direct costs for participants), connection and social support (e.g., foster social networks that provide informational support), education and programming (e.g., enhance awareness of existing services and resources), and government programs and policies (e.g., enforce accessibility standards for indoor and outdoor spaces). The findings of this study provide practical strategies that community organizations and governments can implement to improve access to community-based physical activity opportunities for people with physical disabilities.


Subject(s)
Disabled Persons , Adult , Humans , Disabled Persons/rehabilitation , Social Support , Social Isolation , Policy , Exercise
10.
Plant Physiol ; 157(1): 14-28, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21730200

ABSTRACT

Several angiosperm plant genomes, including Arabidopsis (Arabidopsis thaliana), rice (Oryza sativa), poplar (Populus trichocarpa), and grapevine (Vitis vinifera), have been sequenced, but the lack of reference genomes in gymnosperm phyla reduces our understanding of plant evolution and restricts the potential impacts of genomics research. A gene catalog was developed for the conifer tree Picea glauca (white spruce) through large-scale expressed sequence tag sequencing and full-length cDNA sequencing to facilitate genome characterizations, comparative genomics, and gene mapping. The resource incorporates new and publicly available sequences into 27,720 cDNA clusters, 23,589 of which are represented by full-length insert cDNAs. Expressed sequence tags, mate-pair cDNA clone analysis, and custom sequencing were integrated through an iterative process to improve the accuracy of clustering outcomes. The entire catalog spans 30 Mb of unique transcribed sequence. We estimated that the P. glauca nuclear genome contains up to 32,520 transcribed genes owing to incomplete, partially sequenced, and unsampled transcripts and that its transcriptome could span up to 47 Mb. These estimates are in the same range as the Arabidopsis and rice transcriptomes. Next-generation methods confirmed and enhanced the catalog by providing deeper coverage for rare transcripts, by extending many incomplete clusters, and by augmenting the overall transcriptome coverage to 38 Mb of unique sequence. Genomic sample sequencing at 8.5% of the 19.8-Gb P. glauca genome identified 1,495 clusters representing highly repeated sequences among the cDNA clusters. With a conifer transcriptome in full view, functional and protein domain annotations clearly highlighted the divergences between conifers and angiosperms, likely reflecting their respective evolutionary paths.


Subject(s)
Genome, Plant , Tracheophyta/genetics , DNA, Complementary/genetics , Evolution, Molecular , Expressed Sequence Tags , Multigene Family , RNA, Messenger/genetics
11.
Ann Neurol ; 70(6): 881-6, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22190362

ABSTRACT

OBJECTIVE: Multiple sclerosis (MS) is a complex neurological disease. Genetic linkage analysis and genotyping of candidate genes in families with 4 or more affected individuals more heavily loaded for susceptibility genes has not fully explained familial disease clustering. METHODS: We performed whole exome sequencing to further understand the heightened prevalence of MS in these families. RESULTS: Forty-three individuals with MS (1 from each family) were sequenced to find rare variants in candidate MS susceptibility genes. On average, >58,000 variants were identified in each individual. A rare variant in the CYP27B1 gene causing complete loss of gene function was identified in 1 individual. Homozygosity for this mutation results in vitamin D-dependent rickets I (VDDR1), whereas heterozygosity results in lower calcitriol levels. This variant showed significant heterozygous association in 3,046 parent-affected child trios (p = 1 × 10(-5)). Further genotyping in >12,500 individuals showed that other rare loss of function CYP27B1 variants also conferred significant risk of MS, Peto odds ratio = 4.7 (95% confidence interval, 2.3-9.4; p = 5 × 10(-7)). Four known VDDR1 mutations were identified, all overtransmitted. Heterozygous parents transmitted these alleles to MS offspring 35 of 35× (p = 3 × 10(-9)). INTERPRETATION: A causative role for CYP27B1 in MS is supported; the mutations identified are known to alter function having been shown in vivo to result in rickets when 2 copies are present. CYP27B1 encodes the vitamin D-activating 1-alpha hydroxylase enzyme, and thus a role for vitamin D in MS pathogenesis is strongly implicated.


Subject(s)
25-Hydroxyvitamin D3 1-alpha-Hydroxylase/genetics , Genetic Predisposition to Disease , Multiple Sclerosis/genetics , Mutation/genetics , Age of Onset , Cohort Studies , Exome/genetics , Family Health , Female , Gene Frequency , Genetic Association Studies , Genetic Linkage , Genotype , Humans , Male , Multiple Sclerosis/complications , Vitamin D Deficiency/complications , Vitamin D Deficiency/genetics
12.
Acta Neuropathol ; 124(3): 439-47, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22661320

ABSTRACT

Pediatric glioblastomas (GBM) including diffuse intrinsic pontine gliomas (DIPG) are devastating brain tumors with no effective therapy. Here, we investigated clinical and biological impacts of histone H3.3 mutations. Forty-two DIPGs were tested for H3.3 mutations. Wild-type versus mutated (K27M-H3.3) subgroups were compared for HIST1H3B, IDH, ATRX and TP53 mutations, copy number alterations and clinical outcome. K27M-H3.3 occurred in 71 %, TP53 mutations in 77 % and ATRX mutations in 9 % of DIPGs. ATRX mutations were more frequent in older children (p < 0.0001). No G34V/R-H3.3, IDH1/2 or H3.1 mutations were identified. K27M-H3.3 DIPGs showed specific copy number changes, including all gains/amplifications of PDGFRA and MYC/PVT1 loci. Notably, all long-term survivors were H3.3 wild type and this group of patients had better overall survival. K27M-H3.3 mutation defines clinically and biologically distinct subgroups and is prevalent in DIPG, which will impact future therapeutic trial design. K27M- and G34V-H3.3 have location-based incidence (brainstem/cortex) and potentially play distinct roles in pediatric GBM pathogenesis. K27M-H3.3 is universally associated with short survival in DIPG, while patients wild-type for H3.3 show improved survival. Based on prognostic and therapeutic implications, our findings argue for H3.3-mutation testing at diagnosis, which should be rapidly integrated into the clinical decision-making algorithm, particularly in atypical DIPG.


Subject(s)
Brain Stem Neoplasms/genetics , Glioma/genetics , Histones/genetics , Pons/pathology , Adolescent , Brain Stem Neoplasms/mortality , Brain Stem Neoplasms/pathology , Child , Child, Preschool , Female , Gene Expression Profiling , Glioma/mortality , Glioma/pathology , Humans , Infant , Male , Mutation , Prognosis , Survival Rate
13.
Hum Genet ; 129(5): 573-82, 2011 May.
Article in English | MEDLINE | ID: mdl-21279724

ABSTRACT

The incidence of esophageal squamous cell carcinoma (ESCC) is very high in northeastern Iran. Previously, we reported a strong familial component of ESCC among Turkmens, who constitute approximately one-half of the population of this region. We hypothesized that the genes which cause Fanconi anemia might be candidate genes for ESCC. We sequenced the entire coding regions of 12 Fanconi anemia genes in the germline DNA of 190 Turkmen cases of ESCC. We identified three heterozygous insertion/deletion mutations: one in FANCD2 (p.Val1233del), one in FANCE (p.Val311SerfsX2), and one in FANCL (p.Thr367AsnfsX13). All three patients had a strong family history of ESCC. In addition, four patients (out of 746 tested) were homozygous for the FANCA p.Ser858Arg mutation, compared to none of 1,373 matched controls (OR = 16.7, 95% CI = 6.2-44.2, P = 0.01). The p. Lys3326X mutation in BRCA2 (also known as Fanconi anemia gene FANCD1) was present in 27 of 746 ESCC cases and in 16 of 1,373 controls (OR = 3.38, 95% CI = 1.97-6.91, P = 0.0002). In summary, both heterozygous and homozygous mutations in several Fanconi anemia-predisposing genes are associated with an increased risk of ESCC in Iran.


Subject(s)
Carcinoma, Squamous Cell/genetics , Esophageal Neoplasms/genetics , Fanconi Anemia/genetics , Genetic Predisposition to Disease , INDEL Mutation , Adult , Aged , Aged, 80 and over , Fanconi Anemia Complementation Group D2 Protein/genetics , Fanconi Anemia Complementation Group E Protein/genetics , Fanconi Anemia Complementation Group L Protein/genetics , Female , Genes, BRCA2 , Humans , Iran/epidemiology , Male , Middle Aged , Risk
14.
Genome Med ; 13(1): 169, 2021 10 28.
Article in English | MEDLINE | ID: mdl-34706766

ABSTRACT

BACKGROUND: Québec was the Canadian province most impacted by COVID-19, with 401,462 cases as of September 24th, 2021, and 11,347 deaths due mostly to a very severe first pandemic wave. In April 2020, we assembled the Coronavirus Sequencing in Québec (CoVSeQ) consortium to sequence SARS-CoV-2 genomes in Québec to track viral introduction events and transmission within the province. METHODS: Using genomic epidemiology, we investigated the arrival of SARS-CoV-2 to Québec. We report 2921 high-quality SARS-CoV-2 genomes in the context of > 12,000 publicly available genomes sampled globally over the first pandemic wave (up to June 1st, 2020). By combining phylogenetic and phylodynamic analyses with epidemiological data, we quantify the number of introduction events into Québec, identify their origins, and characterize the spatiotemporal spread of the virus. RESULTS: Conservatively, we estimated approximately 600 independent introduction events, the majority of which happened from spring break until 2 weeks after the Canadian border closed for non-essential travel. Subsequent mass repatriations did not generate large transmission lineages (> 50 sequenced cases), likely due to mandatory quarantine measures in place at the time. Consistent with common spring break and "snowbird" destinations, most of the introductions were inferred to have originated from Europe via the Americas. Once introduced into Québec, viral lineage sizes were overdispersed, with a few lineages giving rise to most infections. Consistent with founder effects, the earliest lineages to arrive tended to spread most successfully. Fewer than 100 viral introductions arrived during spring break, of which 7-12 led to the largest transmission lineages of the first wave (accounting for 52-75% of all sequenced infections). These successful transmission lineages dispersed widely across the province. Transmission lineage size was greatly reduced after March 11th, when a quarantine order for returning travellers was enacted. While this suggests the effectiveness of early public health measures, the biggest transmission lineages had already been ignited prior to this order. CONCLUSIONS: Combined, our results reinforce how, in the absence of tight travel restrictions or quarantine measures, fewer than 100 viral introductions in a week can ensure the establishment of extended transmission chains.


Subject(s)
COVID-19/transmission , COVID-19/epidemiology , COVID-19/virology , Canada/epidemiology , Europe/epidemiology , Genome, Viral , Humans , Molecular Epidemiology , Pandemics , Phylogeny , Public Health , Quebec/epidemiology , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Travel
15.
J Clin Invest ; 131(14)2021 07 15.
Article in English | MEDLINE | ID: mdl-34043590

ABSTRACT

A recent report found that rare predicted loss-of-function (pLOF) variants across 13 candidate genes in TLR3- and IRF7-dependent type I IFN pathways explain up to 3.5% of severe COVID-19 cases. We performed whole-exome or whole-genome sequencing of 1,864 COVID-19 cases (713 with severe and 1,151 with mild disease) and 15,033 ancestry-matched population controls across 4 independent COVID-19 biobanks. We tested whether rare pLOF variants in these 13 genes were associated with severe COVID-19. We identified only 1 rare pLOF mutation across these genes among 713 cases with severe COVID-19 and observed no enrichment of pLOFs in severe cases compared to population controls or mild COVID-19 cases. We found no evidence of association of rare LOF variants in the 13 candidate genes with severe COVID-19 outcomes.


Subject(s)
COVID-19/genetics , COVID-19/immunology , Interferon Type I/genetics , Interferon Type I/immunology , Loss of Function Mutation , SARS-CoV-2 , Adolescent , Adult , Aged , Aged, 80 and over , Case-Control Studies , Child , Child, Preschool , Cohort Studies , Female , Genetic Association Studies , Genetic Predisposition to Disease , Humans , Infant , Infant, Newborn , Interferon Regulatory Factor-7/genetics , Male , Middle Aged , Severity of Illness Index , Toll-Like Receptor 3/genetics , Exome Sequencing , Whole Genome Sequencing , Young Adult
16.
Nature ; 427(6975): 636-40, 2004 Feb 12.
Article in English | MEDLINE | ID: mdl-14737177

ABSTRACT

Leprosy is caused by Mycobacterium leprae and affects about 700,000 individuals each year. It has long been thought that leprosy has a strong genetic component, and recently we mapped a leprosy susceptibility locus to chromosome 6 region q25-q26 (ref. 3). Here we investigate this region further by using a systematic association scan of the chromosomal interval most likely to harbour this leprosy susceptibility locus. In 197 Vietnamese families we found a significant association between leprosy and 17 markers located in a block of approx. 80 kilobases overlapping the 5' regulatory region shared by the Parkinson's disease gene PARK2 and the co-regulated gene PACRG. Possession of as few as two of the 17 risk alleles was highly predictive of leprosy. This was confirmed in a sample of 975 unrelated leprosy cases and controls from Brazil in whom the same alleles were strongly associated with leprosy. Variants in the regulatory region shared by PARK2 and PACRG therefore act as common risk factors for leprosy.


Subject(s)
Genetic Predisposition to Disease , Leprosy/genetics , Proteins/genetics , Ubiquitin-Protein Ligases/genetics , Alleles , Brazil , Case-Control Studies , Chromosome Mapping , Chromosomes, Human, Pair 6/genetics , Gene Expression Profiling , Haplotypes , Humans , Microfilament Proteins , Molecular Chaperones , Phenotype , Polymorphism, Single Nucleotide/genetics , RNA, Messenger/analysis , RNA, Messenger/genetics , Vietnam
17.
Aviat Space Environ Med ; 81(10): 961-4, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20922889

ABSTRACT

INTRODUCTION: When a pilot is referred for vestibular schwannoma (VS), his or her fitness to fly may be questioned. The objective of this retrospective study was to describe a series of VS cases in a pilot population and to discuss their fitness to fly options. METHODS: Between September 2002 and March 2010, the ENT/Head and Neck Surgery Department of the National Pilot Expertise Center conducted nearly 120,000 expert consultations for 40,000 pilots. We examined the files of 10 pilots who were referred to our 2 national experts for VS. RESULTS: At the time of the expert consultation, hypoacusis was present in nine cases (four with total deafness), tinnitus in one case, and vertigo in nine cases. In our series, only 2 of the 10 pilots experienced a negative impact on their fitness to fly. DISCUSSION: Decisions on fitness to fly were based on several factors: minimally disturbed audition, i.e., less than a 35-dB hearing loss with a good speech discrimination score; good balance, i.e., no reported difficulties; no spontaneous nystagmus recorded on videonystagmography (VNG); no postural deviation; and a normal head-shaking test. The delay and the VS's evolution between diagnosis and expert consultation are important because the selection of a treatment to control VS is critical in minimizing the possible associated complications. When a pilot is referred for VS, his or her fitness to fly is determined by the size of the tumor, balance, auditory status, and the follow-up results of these findings. The complications that may arise from VS treatments must also be considered.


Subject(s)
Aerospace Medicine , Disability Evaluation , Neuroma, Acoustic/diagnosis , Adult , Aged , Deafness/etiology , Female , Humans , Male , Middle Aged , Neuroma, Acoustic/complications , Vertigo/etiology , Vestibular Diseases/etiology , Young Adult
18.
medRxiv ; 2020 Dec 21.
Article in English | MEDLINE | ID: mdl-33398295

ABSTRACT

A recent report found that rare predicted loss-of-function (pLOF) variants across 13 candidate genes in TLR3- and IRF7-dependent type I IFN pathways explain up to 3.5% of severe COVID-19 cases. We performed whole-exome or whole-genome sequencing of 1,934 COVID-19 cases (713 with severe and 1,221 with mild disease) and 15,251 ancestry-matched population controls across four independent COVID-19 biobanks. We then tested if rare pLOF variants in these 13 genes were associated with severe COVID-19. We identified only one rare pLOF mutation across these genes amongst 713 cases with severe COVID-19 and observed no enrichment of pLOFs in severe cases compared to population controls or mild COVID-19 cases. We find no evidence of association of rare loss-of-function variants in the proposed 13 candidate genes with severe COVID-19 outcomes.

19.
Front Microbiol ; 9: 2043, 2018.
Article in English | MEDLINE | ID: mdl-30233528

ABSTRACT

Previous observations suggested that microbial communities contribute to coral health and the ecological resilience of coral reefs. However, most studies of coral microbiology focused on prokaryotes and the endosymbiotic algae Symbiodinium. In contrast, knowledge concerning diversity of other protists is still lacking, possibly due to methodological constraints. As most eukaryotic DNA in coral samples was derived from hosts, protist diversity was missed in metagenome analyses. To tackle this issue, we designed blocking primers for Scleractinia sequences amplified with two primer sets that targeted variable loops of the 18S rRNA gene (18SV1V2 and 18SV4). These blocking primers were used on environmental colonies of Pocillopora damicornis sensu lato from two regions with contrasting thermal regimes (Djibouti and New Caledonia). In addition to Symbiodinium clades A/C/D, Licnophora and unidentified coccidia genera were found in many samples. In particular, coccidian sequences formed a robust monophyletic clade with other protists identified in Agaricia, Favia, Montastraea, Mycetophyllia, Porites, and Siderastrea coral colonies. Moreover, Licnophora and coccidians had different distributions between the two geographic regions. A similar pattern was observed between Symbiodinium clades C and A/D. Although we were unable to identify factors responsible for this pattern, nor were we able to confirm that these taxa were closely associated with corals, we believe that these primer sets and the associated blocking primers offer new possibilities to describe the hidden diversity of protists within different coral species.

20.
Diabetes ; 55(10): 2896-902, 2006 Oct.
Article in English | MEDLINE | ID: mdl-17003359

ABSTRACT

The adipokine visfatin (PBEF1) exhibits insulin-mimetic effects and correlates strongly with visceral adiposity. We sequenced visfatin gene exons and 1,480 bp of the promoter in 23 individuals, including 18 individuals from the Quebec Family Study (QFS) with varying degrees of abdominal visceral fat, assessed by computed tomography, and 5 individuals from the Saguenay-Lac-Saint-Jean region of Québec. We identified a synonymous polymorphism in exon 7 (SER301SER) but no nonsynonymous mutations. We observed an additional 10 polymorphisms, including 5 intronic, 4 within the promoter, and 1 within the 3' untranslated region. Further promoter sequencing (816 bp) identified five additional single nucleotide polymorphisms (SNPs) in the QFS population. To investigate the role of visfatin gene variants in obesity-related phenotypes, we genotyped a total of 13 SNPs in the promoter region of the gene. From these, we analyzed the seven common SNPs in the QFS sample (918 participants from 208 families). A significant association was found between two SNPs (rs9770242 and rs1319501), in perfect linkage disequilibrium, and fasting insulin levels (P = 0.002). These SNPs were also associated with fasting glucose (P

Subject(s)
Cytokines/genetics , Insulin/blood , Polymorphism, Single Nucleotide , Promoter Regions, Genetic/genetics , Adult , Female , Founder Effect , France/ethnology , Humans , Linkage Disequilibrium , Male , Nicotinamide Phosphoribosyltransferase , Quebec
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