‘Unprecedented’ study identifies specific genes linked to schizophrenia

Researchers are hopeful their analysis of DNA from more than 300,000 people could inspire ‘radically new treatments’, Andy Gregory reports

Schizophrenia affects around one in 300 people worldwide, according to the WHO (Getty Images/iStockphoto)

The largest-ever genetic study of schizophrenia has identified more than 100 specific genes suspected to be linked to the mental health condition.

In the “unprecedented” study, which it is hoped could inspire “radically new treatments” for the psychiatric disorder, hundreds of researchers across 45 different countries analysed DNA from more than 75,000 people with schizophrenia and nearly 245,000 people without it.

The Cardiff University-led study found a much larger number of genetic links to schizophrenia than ever before – in 287 different regions of the genome, the DNA blueprint of the human body.

Within these regions, the researchers then identified 120 genes likely to contribute to the disorder.

Significantly, the study published in the journal Nature found that genetic risk for schizophrenia is seen in genes concentrated in neurons – nerve cells found in the brain – but not in any other tissue or cell type, suggesting that these cells play a crucial role in the condition.

“These results, achieved through a global collaboration unprecedented in scope, mark an important step forward in our understanding of the origins of schizophrenia,” said Dr Joshua Gordon, director of the US-based National Institute of Mental Health, which funds the Psychiatric Genomics Consortium responsible for the study.

“The findings will allow researchers to focus on specific brain pathways in the ongoing hunt for novel therapies for this serious mental illness.”

While previous research has shown associations between schizophrenia and many anonymous DNA sequences, it has rarely been possible to link the findings to specific genes, according to co-lead author Professor Michael O’Donovan, of Cardiff University.

“The present study not only vastly increased the number of those associations, but we have now been able to link many of them to specific genes, a necessary step in what remains a difficult journey towards understanding the causes of this disorder and identifying new treatments,” Prof O’Donovan said.

According to the World Health Organisation, schizophrenia affects around one in 300 people worldwide, and typically starts in late adolescence or early adulthood.

The study’s findings suggest that abnormal neuron function in schizophrenia affects many brain areas, which could explain its diverse symptoms – which can include hallucinations, delusions and problems with thinking clearly.

“Whilst people with schizophrenia can recover, many do not respond well to treatments, experience long-term problems with their mental and physical health, as well as impacts on relationships, education and work,” said co-lead author Professor James Walters, of Cardiff University.

“We hope the findings in this, and the companion studies, can be used to advance our understanding of the disorder and facilitate the development of radically new treatments.

“However, those processes are often not straightforward, and a lot of work by other neuroscientists is needed to translate the genetic findings into a detailed understanding of disease mechanisms.”

The team’s ability to link to specific genes and areas of biology was enhanced by co-ordinating their work with a companion study involving many of the same scientists, including those from Cardiff University, led by the Broad Institute of Harvard and MIT, which was also published in Nature.