AsianScientist (Sep. 23, 2011) – A team of 250 researchers from more than 20 countries has discovered that common genetic variations contribute to a person’s risk of suffering from schizophrenia and bipolar disorder.
The genome-wide association study included more than 50,000 adults aged 18 or older and provides new molecular evidence that 11 DNA regions in the human genome have strong association with these diseases. This includes six regions not previously observed.
The researchers also found that many of these DNA variants contribute to both schizophrenia and bipolar disorder.
The findings, reported by the Psychiatric Genome-Wide Association Study Consortium and published online in two papers in the journal Nature Genetics, represent significant advances in understanding the causes of these chronic, severe, and debilitating disorders.
“This is the largest study of its kind by far,” said principal investigator of the study, Prof. Patrick F. Sullivan of the University of North Carolina at Chapel Hill.
The study that focused on schizophrenia found strong evidence for seven different places in the human genome, five of which were new and two previously implicated, that contain DNA changes that are significantly associated with schizophrenia, Sullivan said.
And in a joint analysis of a schizophrenia and bipolar disorder sample, the Consortium found three different DNA regions, or loci, in which both disorders reached genome-wide statistical significance.
“This tells us that these disorders, which many of us have considered to be different, actually share fundamental similarity,” Sullivan said.
Schizophrenia and bipolar disorder are common and often devastating brain disorders. Some of the most prominent symptoms in schizophrenia are persistent delusions, hallucinations, and cognitive problems. Bipolar disorder (or manic-depressive illness) is characterized by episodes of severe mood problems including mania and depression.
Both illnesses affect about one percent of the world’s population and usually strike in late adolescence or early adulthood.
Despite the availability of treatments, these illnesses are usually chronic, and response to treatment is often incomplete leading to prolonged disability and personal suffering.
Family history, which reflects genetic inheritance, is a strong risk factor for both schizophrenia and bipolar disorder, and it has generally been assumed that dozens of genes, along with environmental factors, contribute to disease risk.
“The consortium is the largest research consortium ever in psychiatry and [this] is certainly the largest biological experiment we’ve ever done in the field,” Sullivan said.
“We are studying on the order of 90,000 individuals across multiple disorders, while trying to do something for the greater good, which is effectively to go as far and as deep as we can in understanding the genomics of mental illness.”
The two article can be found at:
Ripke S et al. (2011) Genome-wide association study identifies five new schizophrenia loci.
Sklar P et al. (2011) Large-scale genome-wide association analysis of bipolar disorder identifies a new susceptibility locus near ODZ4.
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Source: University of North Carolina, Chapel Hill.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.
#Australia #Graylands Hospital #Hunter Medical Research Institute #Queensland Institute of Medical Research #Schizophrenia Research Institute #The Park Center for Mental Health #University of Melbourne #University of New South Wales #University of Newcastle #University of Queensland #University of Western Australia
