Gene that doubles the risk of schizophrenia identified

Researchers claim to have identified a gene that may double the risk of schizophrenia after being damaged.
This is one of the first times that researchers have uncovered genetic evidence for the underlying causes of schizophrenia, researchers said.
The team found that a disruption of the gene TOP3B, an exceedingly rare occurrence in most parts of the world, is fairly common in a uniquely genetically distinct founder population from North-eastern Finland.
In this population, which has grown in relative isolation for several centuries, the disruption of TOP3B is associated with an increased risk of schizophrenia as well as with impairment in intellectual function and learning.

The biochemical investigation of the protein encoded by the TOP3B gene allowed the researchers to gain first insight into the cellular processes that might be disturbed in the affected individuals.
The study uncovers an important biological pathway that appears to underlie schizophrenia and could contribute to the cognitive impairment that is an important component of this disorder.

"This is a tremendous discovery for our team; not only have we uncovered vital information about the biology behind schizophrenia, but we have also linked this same biological process to a disorder associated with learning difficulties," says Dr Aarno Palotie, lead author from the Wellcome Trust Sanger Institute, the Broad Institute of MIT and Harvard and the Institute for Molecular Medicine Finland.

"Our findings offer great hope for future studies into the genetic basis of schizophrenia and other brain disorders, potentially finding new drug targets against them," said Palotie.
The North-eastern population of Finland has three times the frequency of schizophrenia compared to the national average in Finland, as well as a higher rate of intellectual impairment and learning difficulties.
The team used data collected from this unique population to sift through genomic data for genetic deletions that may influence people's susceptibility to schizophrenia.
They identified a rare genetic deletion affecting TOP3B in the North-eastern Finnish population that increases a person's susceptibility to schizophrenia two-fold and that also is associated with an increased frequency of other disorders of brain development such as intellectual impairment.

They speculate that this deletion directly disrupts the TOP3B gene to cause its effects on the brain.