Scientists have discovered 13 new locations in our genetic code that could help explain the cause of schizophrenia.
The researchers conducted an analysis over 59,000 people, publishing their findings in Nature Genetics. The study included 5,001 schizophrenia patients alongside 6,243 controls. This analysis was followed by a type of review that combines studies, a meta-analysis of studies into genome-wide associations.
They also replicated single nucleotide polymorphisms (SNPs) within 168 genomic regions of independent brain samples. SNPs are the most common type of genetic variation found within the human genome.
The study was done through a collaboration of researchers from the University of North Carolina School of Medicine, the Karolinska Institutet in Sweden, the Stanley Center for Psychiatric Research at the Broad Institute of MIT and Harvard, and the Mt. Sinai School of Medicine in New York.
The results of the analysis identified 22 genome locations, with 13 new locations that they believe are involved in the development of schizophrenia.
Researchers found 13 locations in our genetic code that could play a part in the cause of schizophrenia.
Two genetically determined processes were of particular importance to schizophrenia, the researchers say - the "calcium channel pathway" and the "micro-RNA 137" pathway.
The calcium channel pathway includes the genes CACNA1C and CACNB2. The proteins determined by these genes play an important part in nerve cell processes, the researchers say.
The micro-RNA 137 pathway includes the gene MIR137, a known "regulator of neuronal development," and many other genes are regulated by it.
Professor Patrick Sullivan, lead author and director of the Center for Psychiatric Genomics at the University of North Carolina School of Medicine, says:
"This study gives us the clearest picture to date of two different pathways that might be going wrong in people with schizophrenia.
Now we need to concentrate our research very urgently on these two pathways in our quest to understand what causes this disabling mental illness."
Around 2.4 million American adults have schizophrenia, or 1.1% of the US population over the age of 18, according to mental health statistics from the National Institute of Mental Health. The mental health experts say schizophrenia has long been known to run in families but that the cause has been debated, with some scientists suggesting explanations from brain chemistry and structure, while others have pointed to a particular gene.
However, the researchers of the present study believe their findings mean they are a step closer to identifying the real cause of the mental disorder, and potentially developing new treatments.
"If finding the causes of schizophrenia is like solving a jigsaw puzzle, then these new results give us the corners and some of the pieces on the edge. We have debated this for a century, and we are now zeroing in on answers," says Prof. Sullivan.
"What is really exciting about this is that now we can use standard, off-the-shelf genomic technologies to help us fill in the missing pieces.
We now have a clear and obvious path to getting a fairly complete understanding of the genetic part of schizophrenia. That would not have been possible five years ago."
In other recent news about schizophrenia, an August 2013 study from the University of British Columbia suggested that the mental disorder may be affected by poor ability to track moving objects.
Written by Honor Whiteman