Genetic study brings new schizophrenia insights

Jul 23 2014

Professor Rodney Scott

University of Newcastle researchers have helped unearth more than 100 genetic variants associated with schizophrenia, after contributing to the largest genome-wide study of the disease ever conducted.

The results, published today in the world-leading publication Nature, offer significant insights into susceptibility factors and provide promising therapeutic targets. Previously, only 30 genetic regions (loci) had been identified.

Professor Rodney Scott, Associate Professor Carmel Loughland, Professor Ulli Schall, Emeritus Professor Patricia Michie and Associate Professor Frans Henskens were part of the Psychiatric Genomics Consortium – comprising more than 80 institutions – that coordinated the investigation.

Data from the Newcastle-run Australian Schizophrenia Research Bank (ASRB) was pooled into a sample of 150,000 people, of whom almost 37,000 had been diagnosed with schizophrenia. This enabled researchers to detect 108 loci where the DNA sequence for schizophrenia patients differed from those in people without the disease.

An algorithm developed during the study can calculate a ‘risk score’ for each variant’s contribution to overall disease risk.
Professor Scott said family history studies had indicated a genetic component but researchers now had leads to follow rather than “scrambling about in the dark”.

“It doesn’t mean we can predict who will develop schizophrenia but it gives us tremendous insight into the underlying biology,” he said.
“The few drugs currently developed for the disease are designed to subdue the patient, they don’t target the mechanisms giving rise to schizophrenic behaviours.”

Many of the variants discovered are involved in neurotransmission, highlighting a potential therapeutic avenue, while associations were also found in genes that function in immune processes.

“Intriguingly, there is appears to be some similarities to the loci identified in Multiple Sclerosis, indicating the strong likelihood of an immune response element to schizophrenia,” Professor Scott added. “Something is going on in terms of environment, which is just as powerful as in MS, and without that trigger a person possibly won’t get schizophrenia.”

Associate Professor Loughland, manager of the ASRB, said findings of a biological association between synaptic transmission and inflammation provided a new pathway for investigating the mental, emotional and social impairment experienced by people with schizophrenia.

“Schizophrenia is also associated with extensive co-morbitity. The findings will have implications for clinical practice by highlighting the need for a more holistic approach to treating mental illness, and not just focusing on symptom abatement,” she said.

HMRI is a partnership between the University of Newcastle, Hunter New England Health and the community.