Genetic losses and duplications may cause schizophrenia

The research group, known as the International Schizophrenia Consortium, studied 3,391 cases of schizophrenia and 3,181 comparison subjects. They found that one per cent of the people with schizophrenia had large deletions and duplications on chromosomes 1, 15 and 22. The consortium, from Europe and the USA, was initially organised by Professor Hugh Gurling at UCL (University College London) and Dr Pamela Sklar at Harvard University. Their study is the largest and most complete of its type to date.

Schizophrenia is a common and often devastating brain disorder diagnosed by observing the symptoms of abnormal beliefs, bizarre behaviour, hearing voices, change in personality, difficulty concentrating on tasks, poor cognitive performance and often lack of self care. It affects approximately 1 person in 100. The onset is usually during the teens and the illness can have a tragic effect on the whole of someone's life. All available treatments are limited by unacceptable side effects. The hope for the future relies strongly on understanding the underlying genetic causes and by designing new drugs based on the brain proteins and their systems that have been disturbed by genetic effects.

Professor Hugh Gurling, UCL Mental Health Sciences, said: "Finding so many large and small deletions and duplications was no surprise because we have known for many years that schizophrenia is highly genetic. The surprise was how efficiently and quickly the new technology of studying genes using microarrays has propelled our understanding of schizophrenia, our knowledge about this disorder has been revolutionised and the text books on psychiatry now need rewriting."

Formed in 2006, the International Schizophrenia Consortium is led by senior researchers from 11 institutes in Europe and the USA (see complete list below). The investigators used new genomic technologies and novel analytical techniques developed at the Broad Institute USA to screen these samples for structural variants in the genome, sites where a portion of a chromosome is missing or duplicated. "The Consortium should be recognized for taking the important first step towards unearthing the full underlying genomic architecture of schizophrenia and other psychotic disorders," said Edward Scolnick, MD, Director of the Stanley Center for Psychiatric Research at the Broad Institute. "Only by doing such a large study could we have uncovered these stunning findings to such a high degree of confidence, thus setting the stage for an even more complete understanding of the full genomic contributions to disease. This study could only have been done with the open collaboration of many individuals and institutions dedicated to understanding - and treating - this terrifying disease."

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Notes for Editors

1. For more information, please contact Dr Andrew McQuillin tel: +44 (0)20 7679 9436, mobile: +44 (0)7946538515 or Dr Nick Bass tel: +44 (0)20 7679 9436

2. Alternatively, please contact Ruth Metcalfe in the UCL Media Relations Office on tel: +44 (0)20 7679 9739, mobile: +44 (0)7990 675 947, out of hours +44 (0)7917 271 364, e-mail: r.metcalfe@ucl.ac.uk

3. The paper 'Rare chromosomal deletions and duplications increase risk of schizophrenia' will be published online ahead of print in Nature on Wednesday 30 July at 6pm UK time (1pm US Eastern Time). For copies of the paper, please contact Ruth Metcalfe in UCL Media Relations.

4. Institutional Members of the International Schizophrenia Consortium

Molecular Psychiatry Laboratory, Research Department of Mental Health Sciences, UCL Medical School, Windeyer Institute of Medical Sciences, London, England

Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland

School of Medicine, Cardiff University, Cardiff, Wales

School of Molecular and Clinical Medicine, University of Edinburgh, Edinburgh, Scotland

Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden

Department of Psychiatry, Center for Human Genetic Research, Massachusetts General Hospital,

Departments of Genetics, Psychiatry, and Epidemiology, University of North Carolina at Chapel Hill Queensland Institute of Medical Research, Queensland, Australia

Center for Genomic Psychiatry, University of Southern California, Los Angeles

Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Mass.

Department of Psychiatry and Institute of Molecular Medicine, Trinity College Dublin, Ireland

Additional international contributors include:

The Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Mass.

Department of Neuroscience, Psychiatry, Ulleråker, Uppsala University, Uppsala, Sweden

Department of Medical Genetics, University Hospital Maichin Dom, Sofia, Bulgaria

Department of Psychiatry, First Psychiatric Clinic, Alexander University Hospital, Sofia, Bulgaria

Molecular and Cellular Therapeutics and RCSI Research Institute, Royal College of Surgeons in Ireland, Dublin, Ireland

Camden and Islington NHS Foundation Trust, West Berkshire NHS Trust, West London Mental Health Trust, East London and City NHS Foundation Trust, Queen Mary College, University of London.

Ravenscraig Hospital, Greenock, Scotland

State University of New York - Upstate Medical University, Syracuse, N.Y.

Washington VA Medical Center, Washington, D.C.

Department of Psychiatry, Georgetown University School of Medicine, Washington, D.C.

Department of Psychiatry, Virginia Commonwealth University, Richmond, Virginia

Department of Psychiatry, Sao Miguel, Azores, Portugal

Department of Psychiatry, University of Coimbra, Coimbra, Portugal

5. The study was supported by grants from the Stanley Medical Research Foundation , the National Institute of Mental Health, the Sylvan Herman Foundation. The Wellcome Trust, the Science Foundation Ireland, The UK Neuroscience Research Charitable Trust, The National Alliance for Research into Schizophrenia and Affective disorders USA (NARSAD), the UK Medical Research Council, and many UK NHS Mental Health Trusts.