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Projet Bipolaire |
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Le but de ce projet est d'identifier des gènes causant ou prédisposant aux troubles bipolaires dans le but de mieux comprendre le développement de cette maladie et, éventuellement, d'identifier de nouvelles pistes de traitement. D'un point de vie génétique, la maladie bipolaire fait partie des maladies dites complexes car elle résulte de l'interaction de plusieurs gènes entre eux et avec l'environnement. L'identification de mutations génétiques se fera par séquençage de l'ADN des patients eux-mêmes et de celui des membres de leur famille. Grâce aux technologies de séquençage dites de "nouvelle génération", il est maintenant possible de séquencer tous les gènes d'un individu en une seule expéreince. C'est ce type de technologie qui sera utilisé pour le projet bipolaire.
Financement Le fonctionnement du projet Bipolaire est assuré par une subvention de Génome Québec obtenue dans le cadre de la compétition "Santé humain - volet général" lancée en 2009. Le titre du projet de recherche approuvé est "Identification de gènes importants dans les troubles bipolaires en utilisant une approche de séquençage à haut débit "
Traditionally, the favored model for the genetic architecture of complex diseases is the common disease/common variant hypothesis (CD/CV). Unfortunately, there are very few examples to support this hypothesis, particularly in brain diseases. Clinicians agree that developmental diseases such as Schizophrenia, Autism, Mental Retardation and Tourette Syndrome are highly heterogeneous. It would therefore be surprising that they can be explained by single or even a few common variants. The S2D project was therefore designed based on an alternate hypothesis: the frequent occurrence of rare, de novo, variants as the cause of neurodevelopmental diseases. Another alternative, for diseases such as Amyotrophic Lateral Sclerosis and Tourette Syndrome, is to analyze individuals, both affected and non-affected, from the same family.
Given the scale of the S2D project, its realization will not be possible without the involvement of many institutional partners. The following institutions contribute to the S2D project through direct funding, services and infrastructure.
Identification of cases
Identification and screening of candidate genes One the first task of the S2D Team was to review the literature in order to identify the genes playing a role at the synapse. Approximately 5,000 genes were found to met the critera for "synapticity". Originally, one thousand of these synaptic genes were selected as screening candi
Genetic validation of sequence variants Each sequence variant identified during the screening phase is genetically validated by an independent sequencing reaction while its presence/absence is determine in the parent of the individual exhibiting the variant. This validation step allow us to determine is the varaint occured de novo or if it was transmitted from one of the parent. For familial analysis, we will also determin if the variant is present in other affacted member of the family. For the most promising gene(s), we will screen additional cases to determine if the gene's involvement in the disease or the calculate the frequency at which it is mutated. Finally, control samples will be sequenced to determine the absence of specific gene variants in non-affected individuals. We expect to identify over 18,000 gene variants and approximately 3,000 of these will be genetically validated.
Biologic validation of sequence variants In parallel with genetic validation, the most promising variants will be studied in vivo and in vitro to screen for abnormal synaptic function, processing and stability. Four different models (zebrafish, drosophila, nematode and mouse primary neuron cultures) were chosen in order to study the effects of human synaptic gene variants. This will allow us to identify the most promising mutations for future functional genomics analysis, including transgenic mouse models. We expect to biologically validate numerous variants in approximately 12 to 20 different genes.
The impact of the S2D project on the people, society, and economy of Canada will be manifested in many different forms. First, diagnostics will be improved. Our findings will lead to the development of new diagnostic tests which will allow for accurate information to be transmitted to affected individuals and their families. While this may initially seem to be of relatively minor importance, providing an accurate diagnosis is the keystone on which medicine is based. An accurate diagnosis provides great reassurance to individuals and their families that they suffer from a known and definable disease, reassurance that is particularly beneficial when involving diseases of the brain. Additionally, treatment must always be based on accurate diagnosis as an incorrect diagnosis will lead to inappropriate treatment. Finally, for all diseases, early and accurate diagnosis leads to timely intervention and therefore to improved outcomes. Enhancing social skills or raising an IQ by a few points can make the difference between an individual requiring permanent institutionalization to him or her being able to live and work with minimal intervention from caregivers. This alone can have a significant impact on health, society and quality of life.
People, Society, and Economy The impact of the S2D project on the people, society, and economy of Canada will be manifested in many different forms. First, diagnostics will be improved. Our findings will lead to the development of new diagnostic tests which will allow for accurate information to be transmitted to affected individuals and their families. While this may initially seem to be of relatively minor importance, providing an accurate diagnosis is the keystone on which medicine is based. An accurate diagnosis provides great reassurance to individuals and their families that they suffer from a known and definable disease, reassurance that is particularly beneficial when involving diseases of the brain. Additionally, treatment must always be based on accurate diagnosis as an incorrect diagnosis will lead to inappropriate treatment. Finally, for all diseases, early and accurate diagnosis leads to timely intervention and therefore to improved outcomes. Enhancing social skills or raising an IQ by a few points can make the difference between an individual requiring permanent institutionalization to him or her being able to live and work with minimal intervention from caregivers. This alone can have a significant impact on health, society and quality of life.
Genetics Counseling Another impact of the S2D project is improvements in genetics counseling. Many families (parents or siblings) as well as affected individuals often enquire about the risks of passing disorders on to their offspring. The current lack of available genetic testing significantly limits the accuracy of risk estimates as well as professional assistance in making reproductive decisions. The findings of this project have the potential to improve genetics counseling services made available to the public.
Disease Understanding a few predisposing genes with certainty, these pathways can be explored to identify other genes as well as to create specific treatments. Although it is often difficult to predict how the identification of genes can impact on a disease, an example exists where treatments aimed at a specific pathogenic mechanism (expanded CAG tracts diseases) made possible the treatment of other very different brain disorders sharing this mechanism. Identification of mutated genes could also provide insight into the signaling pathways perturbed in a disease, and allow for the identification of other components of the pathways. This would lead to fundamental new insights in the neurosciences, and in turn could be used to design novel drug screening assays for novel or improved treatments for patients. The results of the S2D project will be disseminated through peer-reviewed publications and the information on gene structure, primers sequence and gene variants will be made available on the internet for the benefit of the international neurosciences community.
Training The students, postdoctoral fellows and personnel hired for the S2D project will acquire a unique expertise in a large-scale genomic research project and in bioinformatics analysis. This will contribute to the development of a skilled work force, thereby maintaining Canada’s leading position in genomics research.
Le projet Bipolaire a débuté en octobre 2010. La première étape a consisté à sélectionner, parmi la collection d'échantillons bipolaires, ceux qui seraient utilisés pour la recherche de mutations. Cette sélection s'est faite selon des critères précis parmi lesquels figuraient la précision du diagnostic, l'histoire familiale ainsi que la quantité et la qualité de l'ADN disponible.
Suite à cette sélection, les échantillons ont été envoyés au Centre d'innovation Génome Québec et Université McGill pour les étapes de capture et de séquençage. La capture des portions codantes de l'ADN est faite en utilisant la technologie SureSelect de la compagnie Agilent Technologies. Plus précisément, nous avons utilisé le kit "SureSelect Human All Exon 50Mb" qui permet la capture de 50Mb de séquence codante. L'ADN ainsi capturé est ensuite séquencé en utilisant le système HiSeq 2000 de la compagnie Illumina. Les séquences d'ADN des premiers échantillons sont présentement en cours d'analyse. Le stockage et l'analyse des données de séquençage sont faits en avec le Réseau québécois de calcul de haute performance (RQCHP). Grâce à la collaboration établie entre le laboratoire du Dr Rouleau et le RQCHP, nous profitons des capacités de stockage et d'analyse du Réseau pour accélérer l'identification de mutations qui causeraient ou prédisposeraient aux troubles bipolaires.
The Bipolar project began in October 2010. The first step was to select, from the collection of bipolar samples, those that would be used to search for mutations. This selection was made according to specific criteria which included the accuracy of diagnosis, family history and the quantity and quality of DNA available.
Following this selection, the samples were sent to the McGill University and Genome Quebec Innovation Centre for capture and sequencing. The capture of the genome codion regions is done using the SureSelect technology developed by Agilent Technologies. More specifically, we used the "All SureSelect Human Exon 50Mb" kit to capture up to 50 Mb of coding sequence. The captured DNA is then sequenced using the HiSeq2000 system from Illumina. The data from the first sequenced samples are currently being analyzed. Storage and analysis of the sequence data are made in collaboration with the Réseau québécois de calcul de haute performance (RQCHP). Based on the collaboration established between Dr. Guy Rouleau's laboratory and RQCHP, we can use the storage and computing capacities of the Réseau to accelerate the identification of mutations that cause or predispose to bipolar disorder.
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Le projet de recherche sur la maladie bipolaire a débuté en octobre 2010 suite à l'obtention d'une subvention de Génome Québec. 
All brain functions are based on networks of neurons that communicate at specialized sites of contact termed synapses. Synapses are thought to form in the embryo largely as a result of genetically pre-programmed, activity-independent and evolutionarily conserved mechanisms. During post-natal development, which is the period during which many developmental brain diseases manifest themselves, synaptic activity is required to select, refine and stabilize mature connectivity patterns. We therefore postulate that defects in synaptic formation and function underlie many common developmental brain diseases that are otherwise characterized by grossly normal structure. Because the number of potential disease-causing genes far exceeded the original funding, we use the synaptic gene hypothesis to select the genes included in the original screen. The introduction of new sequencing technologies, which allow for the analysis of much larger data sets at a cost similar to the original proposition, is now making it possible to sequence a significanly higher number of genes. Therefore, the S2D project is no longer limited to the sequecning of synaptic genes. We are now sequencing the entire exome of each individual, a methodology known as "Exome Sequencing". Because the "synaptic gene" hypothesis is still the most promising one for neurodevelopmental diseases, synaptic genes will receive a higher priority during the analysis phase of the project. 
A collection of approximately 40,000 DNA samples from patients and their relatives suffering from over 150 diseases has been built over the last two decades by Dr. Guy A. Rouleau and his collaborators. Samples from this collection have been selected for the S2D project using specific criteria. For example, for neurodevelopmental diseases, we are looking for new or de novo mutations that are not present in the parent of an affected subject. It is therefore important to select samples for which both parent’s DNA is available. Detailed and well-documented diagnosis is also an important selection criterion to ensure the quality of the results. The project now includes 142 autistic individuals, 190 patients suffering from Mental Retardation, 143 individuals with Schizophrenia, 95 cases of Tourette Syndrome, 40 Obsessive-Compulsive cases, 60 individuals from family affected by Amyotrophic Lateral Sclerosis and hundreds of control samples.
dates for this project. These genes encode for pre- and post-synaptic molecules involved in synapse structure and function as well as molecules affecting cognition. Each of these 1,000 candidate gene were annotated and prioritized for screening based on potential disease relevance and importance to the synapse. Before the implementation of next generation sequencing technology, 500 synaptic genes were screened in individuals suffering from Schizophrenia, Autism and Mental Retardation. Early in 2010, we started using Exome Sequencing for the identification of mutations involved in the studied diseases. The first step of this new method is to capture coding sequences using Agilent Technologies' SureSelect Human All Exon Kit. Approximately 38 Mb of coding genomic DNA is selected for each individual selected for analysis. Each sample is then seqeunce using Life Technologies' SOLiD system. The introduction of Exome Sequencing lead to a significant increase in the number of genes analyzed and therefore increases the probability of finding causative mutation(s). 
Dr. Guy A. Rouleau is a Professor in the Department of Medicine at the Université de Montréal. He is Director of the CHU Ste-Justine Research Centre, Director of the Centre of Excellence in Neuromics of Université de Montréal (CENUM), as well as Director of the Réseau de médecine génétique appliquée du Québec. Dr. Rouleau also supervises a laboratory of more than 40 people working on the genetics of neurological and psychiatric diseases. Over the last 20 years Dr. Rouleau’s work has focused on understanding the genetic basis for brain diseases. More specifically, he has mapped over 20 disease loci, significantly contributing to the identification of over 10 disease-causing genes as well as to a better understanding of the pathogenesis of numerous diseases. Dr. Rouleau studies numerous neurological and psychiatric diseases, including amyotrophic lateral sclerosis, stroke, familial aneurysms, cavernous angiomas, epilepsy, spinocerebellar ataxia, spastic paraplegia, autism, Tourette syndrome, restless legs syndrome, schizophrenia, and bipolar disorder. His laboratory is involved in understanding the pathogenesis of amyotrophic lateral sclerosis, oculopharyngeal muscular dystrophy, hereditary sensory and autonomic neuropathy (pain disorder) and CAG repeat disorders using cell and animal models (mouse, drosophila, zebrafish). Dr. Rouleau has trained numerous scientists and physician-scientists, many of whom currently hold academic positions in various universities across Canada, the USA, Japan, Brazil, and Europe. He has published over 350 peer-reviewed papers including multiple articles in Nature, Nature Genetics, and Cell. He has won numerous awards for his contributions to science and society, including Scientist of the Year (1993, Societé Radio-Canada), Un des grands de l’année (1994, Magazine l’Actualité), Prix Leo-Parizeau (1999, Association Canadienne-Francaise pour l’Avancement de la Science (ACFAS)), and the Michael Smith Award (2000, Canadian Institutes for Health Research). In 2007 Dr. Rouleau was nominated Officer of the National Order of Quebec, the highest distinction bestowed by the Government of Quebec. 
Dr. Martin Alda.... .
Béatrice Godard is an Associate Professor at the Department of Preventive and Social Medicine and Director of the Bioethics Programs at the University of Montreal. A medical sociologist with extensive expertise in bioethics, qualitative and quantitative social science research methodologies, she was an active contributor to the development of guidelines including guidelines on Data Storage and DNA Banking for Biomedical Research, Genetic Screening and Provision of Genetic Services published by the European Society of Human Genetics. Her research work also explores emerging ethical responsibilities at the junction of the research and the clinic. More specifically, she focusses on (1) issues surrounding the communication of genetic research results to participants; (2) the possible ethical duty of genetic service providers to re-contact and inform patients if new information comes to light, or if new risk assessment strategies are developed, when either could be beneficial to the patients’ health; (3) issues surrounding the disclosure of genetic information to biological relatives of a patient in cases where such information could allow those relatives to opt for preventive monitoring, potentially avoiding or delaying disease onset. In addition, Dr Godard is engaged in seeking to better understand prevailing attitudes and behaviours with regard to genetic research, especially (1) in the framework of public consultations on population genetics databanks used for research purposes and (2) the use of genetic information for public health purposes, both in terms of bio-ethical needs-assessment and ethical decision-making frameworks. Her research work is funded by Génome Québec, the Canadian Institutes of Health Research and the Fonds de la recherche en santé du Québec. Béatrice Godard sits on a number of ethics committees, including the National Research Council of Canada and the FRSQ Research Ethics Committee.
Dr. Gustavo Turecki... .