Science for Health
15 October 2012
Researchers from UCL, Birkbeck, Queen Mary and NIMR have been granted a Wellcome Trust Strategic Award to understand how learning disabilities develop in people with Down Syndrome and to identify the processes involved in the decline that often occurs as people with Down Syndrome age.
Down Syndrome is the most common condition involving learning disability, and arises because people have an extra copy of chromosome number 21. Adults with Down syndrome are at greater risk of developing Alzheimer’s disease than the general population and onset tends to occur at an earlier age. One of the reasons for this is believed to be the fact that one of the key genes implicated in Alzheimer’s – the amyloid beta (A4) precursor protein, or APP, gene - is found on chromosome 21; people with Down syndrome carry three copies of this chromosome.
The London Down Syndrome Consortium – LonDownS – will bring together researchers from several institutions and aims to understand individual differences in the genetic, molecular and cellular basis of Down Syndrome with respect to brain changes during infant development and ageing, associated with specific cognitive phenotypes including Alzheimer’s disease.
The consortium includes researchers working in disciplines such as adult and child psychiatry, cognitive neuroscience, genetics and stem cell research: Dr André Strydom (UCL Mental Health Sciences Unit), Professors Elizabeth Fisher and John Hardy (both from UCL Institute of Neurology), Professor Dean Nizetic (Queen Mary, University of London), Dr Victor Tybulewicz (NIMR), Professor Annette Karmiloff-Smith (Birkbeck Centre for Brain & Cognitive Development, University of London).
The project builds upon earlier work by Victor Tybulewicz (pictured) at NIMR and Elizabeth Fisher at UCL. They put human chromosome 21 into a mouse to create a new strain of mouse that was an animal model of human Down Syndrome. This mouse has three copies of the genes on chromosome 21 instead of the normal two, just as humans with Down Syndrome do, and exhibited learning and memory defects, heart defects and other characteristic alterations. In effect, they made a ‘super transgenic’ mouse which carries 250 human genes. The researchers will study the function of analogous genes in these mice.
There are some unusual characteristics of Alzheimer’s, such as the link with Down syndrome and the fact that some cases are asymptomatic, that may in fact provide a key to understanding the disease. Our Consortium will use a variety of disciplines to help us investigate the link between Down Syndrome and Alzheimer’s disease. We hope the insights this provides will help us diagnose the disease sooner and design novel treatments to benefit people with Down Syndrome as well as those with Alzheimer’s Disease.
Principal Applicant, André Strydom
This Award will enable us to translate our work on Down Syndrome from animal models to humans, and will provide new insights into the pathological changes underlying this complex human syndrome.
The new research consortium is asking a very important and timely question: why people with Down syndrome should also be at greater risk of developing Alzheimer’s. We hope that by examining this link, the researchers will provide valuable insights into the neurodegenerative disorder which will benefit the patients themselves, but also offer hope to the many families who are affected by dementia in general.
Dr John Williams, Head of Neuroscience and Mental Health at the Wellcome Trust
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