An international team of researchers has uncovered five new genetic variants that may play a part in influencing a person’s susceptibility to schizophrenia and bipolar disorder – findings which may provide insight into the possible molecular causes of this debilitating disease characterized by hallucinations, delusion and other symptoms.
In the study, published online Sept. 18 in the Advance Online Publication section of Nature Genetics, researchers from the Schizophrenia Psychiatric Genome-Wide Association Study Consortium, an arm of the Psychiatric Genome-Wide Association Study Consortium, reported seven genes – five of which are new, and two of which were previously associated in schizophrenia risk.
One of these genes was found to have a region within it that contained a regulator, MIR137, known for its role in neuronal development and functioning. Four other loci contain predicted targets of MIR137 as well, suggesting that MIR137-mediated dysregulation may be a mechanism involved in schizophrenia.
Researchers from Virginia Commonwealth University, led by Kenneth S. Kendler, M.D., professor of psychiatry, and human and molecular genetics in the VCU School of Medicine, contributed to this study.
“The most important result from this study was our ability to replicate, in a large series of independent samples, the genetic signals we obtained in our first sample. This shows that, with large enough samples and careful statistical analysis, we can detect genetic signals for this critical and severe psychiatric disorder,” said Kendler, director of the Virginia Institute for Psychiatric and Behavioral Genetics at VCU, and third author of the study.
“This now opens up the possibility of clarifying the biological basis of this disorder which could eventually lead to new preventive and treatment possibilities,” he said.
The findings could help researchers better understand the molecular pathways involved in schizophrenia and be used to develop potential target therapies directed at specific molecular pathways.
The consortium conducted a mega-analysis of 17 separate studies, including a two-stage analysis of data from nearly 51,700 individuals of European ancestry.
In the same issue of Nature Genetics, the Psychiatric Genome-Wide Association Study Consortium published findings of a second study which found that many of the DNA variations contribute to both diseases.
Schizophrenia and bipolar disorder 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 study was funded by more than 40 US National Institutes of Health grants and similar numbers of government grants from other countries, along with substantial private and foundation support.
The Psychiatric Genome-Wide Association Study Consortium includes more than 250 researchers from more than 20 countries who have come together to advance knowledge of the genetic causes of mental illness.
EDITOR’S NOTE: A copy of the study is available for reporters by email request from the journal by contacting Neda Afsarmanesh at 212-726-9231 or [email protected].
Sathya Achia Abraham
VCU Communications and Public Relations