Mental deficiency: researchers identify gene mutations that affect learning, memory in children
Jacques L. Michaud, a geneticist at the
“NSMD is a disorder that has many causes,” says Dr. Michaud. “By linking this gene to one kind of NSMD, we better understand the causes and we can work towards a way of identifying and treating this incapacitating condition”.
The identified mutations affect the function of SYNGAP1, a gene that codes for a protein involved in the development and function of the connections between brain cells, also called synapses. The disruption of this gene has been shown to impair memory and learning in mice.
A new approach
Dr. Michaud’s research team hypothesized that new mutations that arise in children - while not present in their parents - may represent a common cause of mental deficiency. “Several observations indicate that new mutations are a frequent cause of neurodevelopmental disorders, but their identification has been difficult because it requires the study of a large fraction of genes, which represents a challenging task,” says Dr. Fadi F. Hamdan, first author of the study.
In order to identify these new mutations, the team took advantage of the platform developed by the Synapse to Diseases consortium, based in
“This discovery illustrates the power of novel technologies that allow researchers to study hundreds of genes in large groups of individuals, and provides validation for the use of such an approach for the exploration of neurodevelopmental disorders,” says Dr. Guy A. Rouleau, Director of Sainte-Justine Research Center and Head of the Synapse to Diseases consortium.
Dr. Michaud and his colleagues are continuing to recruit children and adults with unexplained NSMD for their study. “Mental deficiency is a complicated disorder, whose causes we are only now beginning to understand. In this study, we are looking for subjects in whom there is no clear cause,” adds Dr. Michaud. Families interested in participating in the study can contact Dr. Michaud through the web site www.chu-sainte-justine.org/recruitment_deficiency.
The article “Mutations in SYNGAP1 in Autosomal Non-Syndromic Mental Retardation,” published in the New England Journal of Medicine, was authored by Fadi F. Hamdan, Julie Gauthier, Dan Spiegelman, Anne Noreau, Yan Yang, Stéphanie Pellerin, Sylvia Dobrzeniecka, Mélanie Côté, Elizabeth Perreault-Linck, Lionel Carmant, Guy D’Anjou, Laurent Mottron, Pierre Drapeau, Claude Marineau, Ronald G. Lafrenière, Jean Claude Lacaille, Guy A. Rouleau and Jacques L. Michaud of the Centre of Excellence in Neuromics of Université de Montréal with the collaboration of Éric Fombonne and Ridha Joober of McGill University; Anjene M. Addington and Judith L. Rapoport of the National Institute of Mental Health, Bethesda, Maryland; Lynn E. Delisi of the Nathan S Kline Institute, Orangeburg, New York;Marie-Odile Krebs and Faycal Mouaffak of the Université Paris Descartes, France.
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Source: Nicole Saint-Pierre,
International press attaché
Université de Montréal
Public affairs and communications